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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>36.6. pgtypes Library</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="ecpg-dynamic.html" title="36.5. Dynamic SQL" /><link rel="next" href="ecpg-descriptors.html" title="36.7. Using Descriptor Areas" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">36.6. pgtypes Library</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="ecpg-dynamic.html" title="36.5. Dynamic SQL">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="ecpg.html" title="Chapter 36. ECPG - Embedded SQL in C">Up</a></td><th width="60%" align="center">Chapter 36. <span xmlns="http://www.w3.org/1999/xhtml" class="application">ECPG</span> - Embedded <acronym xmlns="http://www.w3.org/1999/xhtml" class="acronym">SQL</acronym> in C</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="ecpg-descriptors.html" title="36.7. Using Descriptor Areas">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="ECPG-PGTYPES"><div class="titlepage"><div><div><h2 class="title" style="clear: both">36.6. pgtypes Library</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-CSTRINGS">36.6.1. Character Strings</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-NUMERIC">36.6.2. The numeric Type</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-DATE">36.6.3. The date Type</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-TIMESTAMP">36.6.4. The timestamp Type</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-INTERVAL">36.6.5. The interval Type</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-DECIMAL">36.6.6. The decimal Type</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-ERRNO">36.6.7. errno Values of pgtypeslib</a></span></dt><dt><span class="sect2"><a href="ecpg-pgtypes.html#ECPG-PGTYPES-CONSTANTS">36.6.8. Special Constants of pgtypeslib</a></span></dt></dl></div><p>
The pgtypes library maps <span class="productname">PostgreSQL</span> database
types to C equivalents that can be used in C programs. It also offers
functions to do basic calculations with those types within C, i.e., without
the help of the <span class="productname">PostgreSQL</span> server. See the
following example:
</p><pre class="programlisting">
EXEC SQL BEGIN DECLARE SECTION;
date date1;
timestamp ts1, tsout;
interval iv1;
char *out;
EXEC SQL END DECLARE SECTION;
PGTYPESdate_today(&date1);
EXEC SQL SELECT started, duration INTO :ts1, :iv1 FROM datetbl WHERE d=:date1;
PGTYPEStimestamp_add_interval(&ts1, &iv1, &tsout);
out = PGTYPEStimestamp_to_asc(&tsout);
printf("Started + duration: %s\n", out);
PGTYPESchar_free(out);
</pre><p>
</p><div class="sect2" id="ECPG-PGTYPES-CSTRINGS"><div class="titlepage"><div><div><h3 class="title">36.6.1. Character Strings</h3></div></div></div><p>
Some functions such as <code class="function">PGTYPESnumeric_to_asc</code> return
a pointer to a freshly allocated character string. These results should be
freed with <code class="function">PGTYPESchar_free</code> instead of
<code class="function">free</code>. (This is important only on Windows, where
memory allocation and release sometimes need to be done by the same
library.)
</p></div><div class="sect2" id="ECPG-PGTYPES-NUMERIC"><div class="titlepage"><div><div><h3 class="title">36.6.2. The numeric Type</h3></div></div></div><p>
The numeric type offers to do calculations with arbitrary precision. See
<a class="xref" href="datatype-numeric.html" title="8.1. Numeric Types">Section 8.1</a> for the equivalent type in the
<span class="productname">PostgreSQL</span> server. Because of the arbitrary precision this
variable needs to be able to expand and shrink dynamically. That's why you
can only create numeric variables on the heap, by means of the
<code class="function">PGTYPESnumeric_new</code> and <code class="function">PGTYPESnumeric_free</code>
functions. The decimal type, which is similar but limited in precision,
can be created on the stack as well as on the heap.
</p><p>
The following functions can be used to work with the numeric type:
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="function">PGTYPESnumeric_new</code></span></dt><dd><p>
Request a pointer to a newly allocated numeric variable.
</p><pre class="synopsis">
numeric *PGTYPESnumeric_new(void);
</pre><p>
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_free</code></span></dt><dd><p>
Free a numeric type, release all of its memory.
</p><pre class="synopsis">
void PGTYPESnumeric_free(numeric *var);
</pre><p>
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_from_asc</code></span></dt><dd><p>
Parse a numeric type from its string notation.
</p><pre class="synopsis">
numeric *PGTYPESnumeric_from_asc(char *str, char **endptr);
</pre><p>
Valid formats are for example:
<code class="literal">-2</code>,
<code class="literal">.794</code>,
<code class="literal">+3.44</code>,
<code class="literal">592.49E07</code> or
<code class="literal">-32.84e-4</code>.
If the value could be parsed successfully, a valid pointer is returned,
else the NULL pointer. At the moment ECPG always parses the complete
string and so it currently does not support to store the address of the
first invalid character in <code class="literal">*endptr</code>. You can safely
set <code class="literal">endptr</code> to NULL.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_to_asc</code></span></dt><dd><p>
Returns a pointer to a string allocated by <code class="function">malloc</code> that contains the string
representation of the numeric type <code class="literal">num</code>.
</p><pre class="synopsis">
char *PGTYPESnumeric_to_asc(numeric *num, int dscale);
</pre><p>
The numeric value will be printed with <code class="literal">dscale</code> decimal
digits, with rounding applied if necessary.
The result must be freed with <code class="function">PGTYPESchar_free()</code>.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_add</code></span></dt><dd><p>
Add two numeric variables into a third one.
</p><pre class="synopsis">
int PGTYPESnumeric_add(numeric *var1, numeric *var2, numeric *result);
</pre><p>
The function adds the variables <code class="literal">var1</code> and
<code class="literal">var2</code> into the result variable
<code class="literal">result</code>.
The function returns 0 on success and -1 in case of error.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_sub</code></span></dt><dd><p>
Subtract two numeric variables and return the result in a third one.
</p><pre class="synopsis">
int PGTYPESnumeric_sub(numeric *var1, numeric *var2, numeric *result);
</pre><p>
The function subtracts the variable <code class="literal">var2</code> from
the variable <code class="literal">var1</code>. The result of the operation is
stored in the variable <code class="literal">result</code>.
The function returns 0 on success and -1 in case of error.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_mul</code></span></dt><dd><p>
Multiply two numeric variables and return the result in a third one.
</p><pre class="synopsis">
int PGTYPESnumeric_mul(numeric *var1, numeric *var2, numeric *result);
</pre><p>
The function multiplies the variables <code class="literal">var1</code> and
<code class="literal">var2</code>. The result of the operation is stored in the
variable <code class="literal">result</code>.
The function returns 0 on success and -1 in case of error.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_div</code></span></dt><dd><p>
Divide two numeric variables and return the result in a third one.
</p><pre class="synopsis">
int PGTYPESnumeric_div(numeric *var1, numeric *var2, numeric *result);
</pre><p>
The function divides the variables <code class="literal">var1</code> by
<code class="literal">var2</code>. The result of the operation is stored in the
variable <code class="literal">result</code>.
The function returns 0 on success and -1 in case of error.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_cmp</code></span></dt><dd><p>
Compare two numeric variables.
</p><pre class="synopsis">
int PGTYPESnumeric_cmp(numeric *var1, numeric *var2)
</pre><p>
This function compares two numeric variables. In case of error,
<code class="literal">INT_MAX</code> is returned. On success, the function
returns one of three possible results:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
1, if <code class="literal">var1</code> is bigger than <code class="literal">var2</code>
</p></li><li class="listitem"><p>
-1, if <code class="literal">var1</code> is smaller than <code class="literal">var2</code>
</p></li><li class="listitem"><p>
0, if <code class="literal">var1</code> and <code class="literal">var2</code> are equal
</p></li></ul></div><p>
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_from_int</code></span></dt><dd><p>
Convert an int variable to a numeric variable.
</p><pre class="synopsis">
int PGTYPESnumeric_from_int(signed int int_val, numeric *var);
</pre><p>
This function accepts a variable of type signed int and stores it
in the numeric variable <code class="literal">var</code>. Upon success, 0 is returned and
-1 in case of a failure.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_from_long</code></span></dt><dd><p>
Convert a long int variable to a numeric variable.
</p><pre class="synopsis">
int PGTYPESnumeric_from_long(signed long int long_val, numeric *var);
</pre><p>
This function accepts a variable of type signed long int and stores it
in the numeric variable <code class="literal">var</code>. Upon success, 0 is returned and
-1 in case of a failure.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_copy</code></span></dt><dd><p>
Copy over one numeric variable into another one.
</p><pre class="synopsis">
int PGTYPESnumeric_copy(numeric *src, numeric *dst);
</pre><p>
This function copies over the value of the variable that
<code class="literal">src</code> points to into the variable that <code class="literal">dst</code>
points to. It returns 0 on success and -1 if an error occurs.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_from_double</code></span></dt><dd><p>
Convert a variable of type double to a numeric.
</p><pre class="synopsis">
int PGTYPESnumeric_from_double(double d, numeric *dst);
</pre><p>
This function accepts a variable of type double and stores the result
in the variable that <code class="literal">dst</code> points to. It returns 0 on success
and -1 if an error occurs.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_to_double</code></span></dt><dd><p>
Convert a variable of type numeric to double.
</p><pre class="synopsis">
int PGTYPESnumeric_to_double(numeric *nv, double *dp)
</pre><p>
The function converts the numeric value from the variable that
<code class="literal">nv</code> points to into the double variable that <code class="literal">dp</code> points
to. It returns 0 on success and -1 if an error occurs, including
overflow. On overflow, the global variable <code class="literal">errno</code> will be set
to <code class="literal">PGTYPES_NUM_OVERFLOW</code> additionally.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_to_int</code></span></dt><dd><p>
Convert a variable of type numeric to int.
</p><pre class="synopsis">
int PGTYPESnumeric_to_int(numeric *nv, int *ip);
</pre><p>
The function converts the numeric value from the variable that
<code class="literal">nv</code> points to into the integer variable that <code class="literal">ip</code>
points to. It returns 0 on success and -1 if an error occurs, including
overflow. On overflow, the global variable <code class="literal">errno</code> will be set
to <code class="literal">PGTYPES_NUM_OVERFLOW</code> additionally.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_to_long</code></span></dt><dd><p>
Convert a variable of type numeric to long.
</p><pre class="synopsis">
int PGTYPESnumeric_to_long(numeric *nv, long *lp);
</pre><p>
The function converts the numeric value from the variable that
<code class="literal">nv</code> points to into the long integer variable that
<code class="literal">lp</code> points to. It returns 0 on success and -1 if an error
occurs, including overflow. On overflow, the global variable
<code class="literal">errno</code> will be set to <code class="literal">PGTYPES_NUM_OVERFLOW</code>
additionally.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_to_decimal</code></span></dt><dd><p>
Convert a variable of type numeric to decimal.
</p><pre class="synopsis">
int PGTYPESnumeric_to_decimal(numeric *src, decimal *dst);
</pre><p>
The function converts the numeric value from the variable that
<code class="literal">src</code> points to into the decimal variable that
<code class="literal">dst</code> points to. It returns 0 on success and -1 if an error
occurs, including overflow. On overflow, the global variable
<code class="literal">errno</code> will be set to <code class="literal">PGTYPES_NUM_OVERFLOW</code>
additionally.
</p></dd><dt><span class="term"><code class="function">PGTYPESnumeric_from_decimal</code></span></dt><dd><p>
Convert a variable of type decimal to numeric.
</p><pre class="synopsis">
int PGTYPESnumeric_from_decimal(decimal *src, numeric *dst);
</pre><p>
The function converts the decimal value from the variable that
<code class="literal">src</code> points to into the numeric variable that
<code class="literal">dst</code> points to. It returns 0 on success and -1 if an error
occurs. Since the decimal type is implemented as a limited version of
the numeric type, overflow cannot occur with this conversion.
</p></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-DATE"><div class="titlepage"><div><div><h3 class="title">36.6.3. The date Type</h3></div></div></div><p>
The date type in C enables your programs to deal with data of the SQL type
date. See <a class="xref" href="datatype-datetime.html" title="8.5. Date/Time Types">Section 8.5</a> for the equivalent type in the
<span class="productname">PostgreSQL</span> server.
</p><p>
The following functions can be used to work with the date type:
</p><div class="variablelist"><dl class="variablelist"><dt id="PGTYPESDATEFROMTIMESTAMP"><span class="term"><code class="function">PGTYPESdate_from_timestamp</code></span></dt><dd><p>
Extract the date part from a timestamp.
</p><pre class="synopsis">
date PGTYPESdate_from_timestamp(timestamp dt);
</pre><p>
The function receives a timestamp as its only argument and returns the
extracted date part from this timestamp.
</p></dd><dt id="PGTYPESDATEFROMASC"><span class="term"><code class="function">PGTYPESdate_from_asc</code></span></dt><dd><p>
Parse a date from its textual representation.
</p><pre class="synopsis">
date PGTYPESdate_from_asc(char *str, char **endptr);
</pre><p>
The function receives a C char* string <code class="literal">str</code> and a pointer to
a C char* string <code class="literal">endptr</code>. At the moment ECPG always parses
the complete string and so it currently does not support to store the
address of the first invalid character in <code class="literal">*endptr</code>.
You can safely set <code class="literal">endptr</code> to NULL.
</p><p>
Note that the function always assumes MDY-formatted dates and there is
currently no variable to change that within ECPG.
</p><p>
<a class="xref" href="ecpg-pgtypes.html#ECPG-PGTYPESDATE-FROM-ASC-TABLE" title="Table 36.2. Valid Input Formats for PGTYPESdate_from_asc">Table 36.2</a> shows the allowed input formats.
</p><div class="table" id="ECPG-PGTYPESDATE-FROM-ASC-TABLE"><p class="title"><strong>Table 36.2. Valid Input Formats for <code class="function">PGTYPESdate_from_asc</code></strong></p><div class="table-contents"><table class="table" summary="Valid Input Formats for PGTYPESdate_from_asc" border="1"><colgroup><col /><col /></colgroup><thead><tr><th>Input</th><th>Result</th></tr></thead><tbody><tr><td><code class="literal">January 8, 1999</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">1999-01-08</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">1/8/1999</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">1/18/1999</code></td><td><code class="literal">January 18, 1999</code></td></tr><tr><td><code class="literal">01/02/03</code></td><td><code class="literal">February 1, 2003</code></td></tr><tr><td><code class="literal">1999-Jan-08</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">Jan-08-1999</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">08-Jan-1999</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">99-Jan-08</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">08-Jan-99</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">08-Jan-06</code></td><td><code class="literal">January 8, 2006</code></td></tr><tr><td><code class="literal">Jan-08-99</code></td><td><code class="literal">January 8, 1999</code></td></tr><tr><td><code class="literal">19990108</code></td><td><code class="literal">ISO 8601; January 8, 1999</code></td></tr><tr><td><code class="literal">990108</code></td><td><code class="literal">ISO 8601; January 8, 1999</code></td></tr><tr><td><code class="literal">1999.008</code></td><td><code class="literal">year and day of year</code></td></tr><tr><td><code class="literal">J2451187</code></td><td><code class="literal">Julian day</code></td></tr><tr><td><code class="literal">January 8, 99 BC</code></td><td><code class="literal">year 99 before the Common Era</code></td></tr></tbody></table></div></div><br class="table-break" /></dd><dt id="PGTYPESDATETOASC"><span class="term"><code class="function">PGTYPESdate_to_asc</code></span></dt><dd><p>
Return the textual representation of a date variable.
</p><pre class="synopsis">
char *PGTYPESdate_to_asc(date dDate);
</pre><p>
The function receives the date <code class="literal">dDate</code> as its only parameter.
It will output the date in the form <code class="literal">1999-01-18</code>, i.e., in the
<code class="literal">YYYY-MM-DD</code> format.
The result must be freed with <code class="function">PGTYPESchar_free()</code>.
</p></dd><dt id="PGTYPESDATEJULMDY"><span class="term"><code class="function">PGTYPESdate_julmdy</code></span></dt><dd><p>
Extract the values for the day, the month and the year from a variable
of type date.
</p><pre class="synopsis">
void PGTYPESdate_julmdy(date d, int *mdy);
</pre><p>
The function receives the date <code class="literal">d</code> and a pointer to an array
of 3 integer values <code class="literal">mdy</code>. The variable name indicates
the sequential order: <code class="literal">mdy[0]</code> will be set to contain the
number of the month, <code class="literal">mdy[1]</code> will be set to the value of the
day and <code class="literal">mdy[2]</code> will contain the year.
</p></dd><dt id="PGTYPESDATEMDYJUL"><span class="term"><code class="function">PGTYPESdate_mdyjul</code></span></dt><dd><p>
Create a date value from an array of 3 integers that specify the
day, the month and the year of the date.
</p><pre class="synopsis">
void PGTYPESdate_mdyjul(int *mdy, date *jdate);
</pre><p>
The function receives the array of the 3 integers (<code class="literal">mdy</code>) as
its first argument and as its second argument a pointer to a variable
of type date that should hold the result of the operation.
</p></dd><dt id="PGTYPESDATEDAYOFWEEK"><span class="term"><code class="function">PGTYPESdate_dayofweek</code></span></dt><dd><p>
Return a number representing the day of the week for a date value.
</p><pre class="synopsis">
int PGTYPESdate_dayofweek(date d);
</pre><p>
The function receives the date variable <code class="literal">d</code> as its only
argument and returns an integer that indicates the day of the week for
this date.
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
0 - Sunday
</p></li><li class="listitem"><p>
1 - Monday
</p></li><li class="listitem"><p>
2 - Tuesday
</p></li><li class="listitem"><p>
3 - Wednesday
</p></li><li class="listitem"><p>
4 - Thursday
</p></li><li class="listitem"><p>
5 - Friday
</p></li><li class="listitem"><p>
6 - Saturday
</p></li></ul></div><p>
</p></dd><dt id="PGTYPESDATETODAY"><span class="term"><code class="function">PGTYPESdate_today</code></span></dt><dd><p>
Get the current date.
</p><pre class="synopsis">
void PGTYPESdate_today(date *d);
</pre><p>
The function receives a pointer to a date variable (<code class="literal">d</code>)
that it sets to the current date.
</p></dd><dt id="PGTYPESDATEFMTASC"><span class="term"><code class="function">PGTYPESdate_fmt_asc</code></span></dt><dd><p>
Convert a variable of type date to its textual representation using a
format mask.
</p><pre class="synopsis">
int PGTYPESdate_fmt_asc(date dDate, char *fmtstring, char *outbuf);
</pre><p>
The function receives the date to convert (<code class="literal">dDate</code>), the
format mask (<code class="literal">fmtstring</code>) and the string that will hold the
textual representation of the date (<code class="literal">outbuf</code>).
</p><p>
On success, 0 is returned and a negative value if an error occurred.
</p><p>
The following literals are the field specifiers you can use:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
<code class="literal">dd</code> - The number of the day of the month.
</p></li><li class="listitem"><p>
<code class="literal">mm</code> - The number of the month of the year.
</p></li><li class="listitem"><p>
<code class="literal">yy</code> - The number of the year as a two digit number.
</p></li><li class="listitem"><p>
<code class="literal">yyyy</code> - The number of the year as a four digit number.
</p></li><li class="listitem"><p>
<code class="literal">ddd</code> - The name of the day (abbreviated).
</p></li><li class="listitem"><p>
<code class="literal">mmm</code> - The name of the month (abbreviated).
</p></li></ul></div><p>
All other characters are copied 1:1 to the output string.
</p><p>
<a class="xref" href="ecpg-pgtypes.html#ECPG-PGTYPESDATE-FMT-ASC-EXAMPLE-TABLE" title="Table 36.3. Valid Input Formats for PGTYPESdate_fmt_asc">Table 36.3</a> indicates a few possible formats. This will give
you an idea of how to use this function. All output lines are based on
the same date: November 23, 1959.
</p><div class="table" id="ECPG-PGTYPESDATE-FMT-ASC-EXAMPLE-TABLE"><p class="title"><strong>Table 36.3. Valid Input Formats for <code class="function">PGTYPESdate_fmt_asc</code></strong></p><div class="table-contents"><table class="table" summary="Valid Input Formats for PGTYPESdate_fmt_asc" border="1"><colgroup><col /><col /></colgroup><thead><tr><th>Format</th><th>Result</th></tr></thead><tbody><tr><td><code class="literal">mmddyy</code></td><td><code class="literal">112359</code></td></tr><tr><td><code class="literal">ddmmyy</code></td><td><code class="literal">231159</code></td></tr><tr><td><code class="literal">yymmdd</code></td><td><code class="literal">591123</code></td></tr><tr><td><code class="literal">yy/mm/dd</code></td><td><code class="literal">59/11/23</code></td></tr><tr><td><code class="literal">yy mm dd</code></td><td><code class="literal">59 11 23</code></td></tr><tr><td><code class="literal">yy.mm.dd</code></td><td><code class="literal">59.11.23</code></td></tr><tr><td><code class="literal">.mm.yyyy.dd.</code></td><td><code class="literal">.11.1959.23.</code></td></tr><tr><td><code class="literal">mmm. dd, yyyy</code></td><td><code class="literal">Nov. 23, 1959</code></td></tr><tr><td><code class="literal">mmm dd yyyy</code></td><td><code class="literal">Nov 23 1959</code></td></tr><tr><td><code class="literal">yyyy dd mm</code></td><td><code class="literal">1959 23 11</code></td></tr><tr><td><code class="literal">ddd, mmm. dd, yyyy</code></td><td><code class="literal">Mon, Nov. 23, 1959</code></td></tr><tr><td><code class="literal">(ddd) mmm. dd, yyyy</code></td><td><code class="literal">(Mon) Nov. 23, 1959</code></td></tr></tbody></table></div></div><br class="table-break" /></dd><dt id="PGTYPESDATEDEFMTASC"><span class="term"><code class="function">PGTYPESdate_defmt_asc</code></span></dt><dd><p>
Use a format mask to convert a C <code class="type">char*</code> string to a value of type
date.
</p><pre class="synopsis">
int PGTYPESdate_defmt_asc(date *d, char *fmt, char *str);
</pre><p>
The function receives a pointer to the date value that should hold the
result of the operation (<code class="literal">d</code>), the format mask to use for
parsing the date (<code class="literal">fmt</code>) and the C char* string containing
the textual representation of the date (<code class="literal">str</code>). The textual
representation is expected to match the format mask. However you do not
need to have a 1:1 mapping of the string to the format mask. The
function only analyzes the sequential order and looks for the literals
<code class="literal">yy</code> or <code class="literal">yyyy</code> that indicate the
position of the year, <code class="literal">mm</code> to indicate the position of
the month and <code class="literal">dd</code> to indicate the position of the
day.
</p><p>
<a class="xref" href="ecpg-pgtypes.html#ECPG-RDEFMTDATE-EXAMPLE-TABLE" title="Table 36.4. Valid Input Formats for rdefmtdate">Table 36.4</a> indicates a few possible formats. This will give
you an idea of how to use this function.
</p><div class="table" id="ECPG-RDEFMTDATE-EXAMPLE-TABLE"><p class="title"><strong>Table 36.4. Valid Input Formats for <code class="function">rdefmtdate</code></strong></p><div class="table-contents"><table class="table" summary="Valid Input Formats for rdefmtdate" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Format</th><th>String</th><th>Result</th></tr></thead><tbody><tr><td><code class="literal">ddmmyy</code></td><td><code class="literal">21-2-54</code></td><td><code class="literal">1954-02-21</code></td></tr><tr><td><code class="literal">ddmmyy</code></td><td><code class="literal">2-12-54</code></td><td><code class="literal">1954-12-02</code></td></tr><tr><td><code class="literal">ddmmyy</code></td><td><code class="literal">20111954</code></td><td><code class="literal">1954-11-20</code></td></tr><tr><td><code class="literal">ddmmyy</code></td><td><code class="literal">130464</code></td><td><code class="literal">1964-04-13</code></td></tr><tr><td><code class="literal">mmm.dd.yyyy</code></td><td><code class="literal">MAR-12-1967</code></td><td><code class="literal">1967-03-12</code></td></tr><tr><td><code class="literal">yy/mm/dd</code></td><td><code class="literal">1954, February 3rd</code></td><td><code class="literal">1954-02-03</code></td></tr><tr><td><code class="literal">mmm.dd.yyyy</code></td><td><code class="literal">041269</code></td><td><code class="literal">1969-04-12</code></td></tr><tr><td><code class="literal">yy/mm/dd</code></td><td><code class="literal">In the year 2525, in the month of July, mankind will be alive on the 28th day</code></td><td><code class="literal">2525-07-28</code></td></tr><tr><td><code class="literal">dd-mm-yy</code></td><td><code class="literal">I said on the 28th of July in the year 2525</code></td><td><code class="literal">2525-07-28</code></td></tr><tr><td><code class="literal">mmm.dd.yyyy</code></td><td><code class="literal">9/14/58</code></td><td><code class="literal">1958-09-14</code></td></tr><tr><td><code class="literal">yy/mm/dd</code></td><td><code class="literal">47/03/29</code></td><td><code class="literal">1947-03-29</code></td></tr><tr><td><code class="literal">mmm.dd.yyyy</code></td><td><code class="literal">oct 28 1975</code></td><td><code class="literal">1975-10-28</code></td></tr><tr><td><code class="literal">mmddyy</code></td><td><code class="literal">Nov 14th, 1985</code></td><td><code class="literal">1985-11-14</code></td></tr></tbody></table></div></div><br class="table-break" /></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-TIMESTAMP"><div class="titlepage"><div><div><h3 class="title">36.6.4. The timestamp Type</h3></div></div></div><p>
The timestamp type in C enables your programs to deal with data of the SQL
type timestamp. See <a class="xref" href="datatype-datetime.html" title="8.5. Date/Time Types">Section 8.5</a> for the equivalent
type in the <span class="productname">PostgreSQL</span> server.
</p><p>
The following functions can be used to work with the timestamp type:
</p><div class="variablelist"><dl class="variablelist"><dt id="PGTYPESTIMESTAMPFROMASC"><span class="term"><code class="function">PGTYPEStimestamp_from_asc</code></span></dt><dd><p>
Parse a timestamp from its textual representation into a timestamp
variable.
</p><pre class="synopsis">
timestamp PGTYPEStimestamp_from_asc(char *str, char **endptr);
</pre><p>
The function receives the string to parse (<code class="literal">str</code>) and a
pointer to a C char* (<code class="literal">endptr</code>).
At the moment ECPG always parses
the complete string and so it currently does not support to store the
address of the first invalid character in <code class="literal">*endptr</code>.
You can safely set <code class="literal">endptr</code> to NULL.
</p><p>
The function returns the parsed timestamp on success. On error,
<code class="literal">PGTYPESInvalidTimestamp</code> is returned and <code class="varname">errno</code> is
set to <code class="literal">PGTYPES_TS_BAD_TIMESTAMP</code>. See <a class="xref" href="ecpg-pgtypes.html#PGTYPESINVALIDTIMESTAMP"><code class="literal">PGTYPESInvalidTimestamp</code></a> for important notes on this value.
</p><p>
In general, the input string can contain any combination of an allowed
date specification, a whitespace character and an allowed time
specification. Note that time zones are not supported by ECPG. It can
parse them but does not apply any calculation as the
<span class="productname">PostgreSQL</span> server does for example. Timezone
specifiers are silently discarded.
</p><p>
<a class="xref" href="ecpg-pgtypes.html#ECPG-PGTYPESTIMESTAMP-FROM-ASC-EXAMPLE-TABLE" title="Table 36.5. Valid Input Formats for PGTYPEStimestamp_from_asc">Table 36.5</a> contains a few examples for input strings.
</p><div class="table" id="ECPG-PGTYPESTIMESTAMP-FROM-ASC-EXAMPLE-TABLE"><p class="title"><strong>Table 36.5. Valid Input Formats for <code class="function">PGTYPEStimestamp_from_asc</code></strong></p><div class="table-contents"><table class="table" summary="Valid Input Formats for PGTYPEStimestamp_from_asc" border="1"><colgroup><col /><col /></colgroup><thead><tr><th>Input</th><th>Result</th></tr></thead><tbody><tr><td><code class="literal">1999-01-08 04:05:06</code></td><td><code class="literal">1999-01-08 04:05:06</code></td></tr><tr><td><code class="literal">January 8 04:05:06 1999 PST</code></td><td><code class="literal">1999-01-08 04:05:06</code></td></tr><tr><td><code class="literal">1999-Jan-08 04:05:06.789-8</code></td><td><code class="literal">1999-01-08 04:05:06.789 (time zone specifier ignored)</code></td></tr><tr><td><code class="literal">J2451187 04:05-08:00</code></td><td><code class="literal">1999-01-08 04:05:00 (time zone specifier ignored)</code></td></tr></tbody></table></div></div><br class="table-break" /></dd><dt id="PGTYPESTIMESTAMPTOASC"><span class="term"><code class="function">PGTYPEStimestamp_to_asc</code></span></dt><dd><p>
Converts a date to a C char* string.
</p><pre class="synopsis">
char *PGTYPEStimestamp_to_asc(timestamp tstamp);
</pre><p>
The function receives the timestamp <code class="literal">tstamp</code> as
its only argument and returns an allocated string that contains the
textual representation of the timestamp.
The result must be freed with <code class="function">PGTYPESchar_free()</code>.
</p></dd><dt id="PGTYPESTIMESTAMPCURRENT"><span class="term"><code class="function">PGTYPEStimestamp_current</code></span></dt><dd><p>
Retrieve the current timestamp.
</p><pre class="synopsis">
void PGTYPEStimestamp_current(timestamp *ts);
</pre><p>
The function retrieves the current timestamp and saves it into the
timestamp variable that <code class="literal">ts</code> points to.
</p></dd><dt id="PGTYPESTIMESTAMPFMTASC"><span class="term"><code class="function">PGTYPEStimestamp_fmt_asc</code></span></dt><dd><p>
Convert a timestamp variable to a C char* using a format mask.
</p><pre class="synopsis">
int PGTYPEStimestamp_fmt_asc(timestamp *ts, char *output, int str_len, char *fmtstr);
</pre><p>
The function receives a pointer to the timestamp to convert as its
first argument (<code class="literal">ts</code>), a pointer to the output buffer
(<code class="literal">output</code>), the maximal length that has been allocated for
the output buffer (<code class="literal">str_len</code>) and the format mask to
use for the conversion (<code class="literal">fmtstr</code>).
</p><p>
Upon success, the function returns 0 and a negative value if an
error occurred.
</p><p>
You can use the following format specifiers for the format mask. The
format specifiers are the same ones that are used in the
<code class="function">strftime</code> function in <span class="productname">libc</span>. Any
non-format specifier will be copied into the output buffer.
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
<code class="literal">%A</code> - is replaced by national representation of
the full weekday name.
</p></li><li class="listitem"><p>
<code class="literal">%a</code> - is replaced by national representation of
the abbreviated weekday name.
</p></li><li class="listitem"><p>
<code class="literal">%B</code> - is replaced by national representation of
the full month name.
</p></li><li class="listitem"><p>
<code class="literal">%b</code> - is replaced by national representation of
the abbreviated month name.
</p></li><li class="listitem"><p>
<code class="literal">%C</code> - is replaced by (year / 100) as decimal
number; single digits are preceded by a zero.
</p></li><li class="listitem"><p>
<code class="literal">%c</code> - is replaced by national representation of
time and date.
</p></li><li class="listitem"><p>
<code class="literal">%D</code> - is equivalent to
<code class="literal">%m/%d/%y</code>.
</p></li><li class="listitem"><p>
<code class="literal">%d</code> - is replaced by the day of the month as a
decimal number (01-31).
</p></li><li class="listitem"><p>
<code class="literal">%E*</code> <code class="literal">%O*</code> - POSIX locale
extensions. The sequences
<code class="literal">%Ec</code>
<code class="literal">%EC</code>
<code class="literal">%Ex</code>
<code class="literal">%EX</code>
<code class="literal">%Ey</code>
<code class="literal">%EY</code>
<code class="literal">%Od</code>
<code class="literal">%Oe</code>
<code class="literal">%OH</code>
<code class="literal">%OI</code>
<code class="literal">%Om</code>
<code class="literal">%OM</code>
<code class="literal">%OS</code>
<code class="literal">%Ou</code>
<code class="literal">%OU</code>
<code class="literal">%OV</code>
<code class="literal">%Ow</code>
<code class="literal">%OW</code>
<code class="literal">%Oy</code>
are supposed to provide alternative representations.
</p><p>
Additionally <code class="literal">%OB</code> implemented to represent
alternative months names (used standalone, without day mentioned).
</p></li><li class="listitem"><p>
<code class="literal">%e</code> - is replaced by the day of month as a decimal
number (1-31); single digits are preceded by a blank.
</p></li><li class="listitem"><p>
<code class="literal">%F</code> - is equivalent to <code class="literal">%Y-%m-%d</code>.
</p></li><li class="listitem"><p>
<code class="literal">%G</code> - is replaced by a year as a decimal number
with century. This year is the one that contains the greater part of
the week (Monday as the first day of the week).
</p></li><li class="listitem"><p>
<code class="literal">%g</code> - is replaced by the same year as in
<code class="literal">%G</code>, but as a decimal number without century
(00-99).
</p></li><li class="listitem"><p>
<code class="literal">%H</code> - is replaced by the hour (24-hour clock) as a
decimal number (00-23).
</p></li><li class="listitem"><p>
<code class="literal">%h</code> - the same as <code class="literal">%b</code>.
</p></li><li class="listitem"><p>
<code class="literal">%I</code> - is replaced by the hour (12-hour clock) as a
decimal number (01-12).
</p></li><li class="listitem"><p>
<code class="literal">%j</code> - is replaced by the day of the year as a
decimal number (001-366).
</p></li><li class="listitem"><p>
<code class="literal">%k</code> - is replaced by the hour (24-hour clock) as a
decimal number (0-23); single digits are preceded by a blank.
</p></li><li class="listitem"><p>
<code class="literal">%l</code> - is replaced by the hour (12-hour clock) as a
decimal number (1-12); single digits are preceded by a blank.
</p></li><li class="listitem"><p>
<code class="literal">%M</code> - is replaced by the minute as a decimal
number (00-59).
</p></li><li class="listitem"><p>
<code class="literal">%m</code> - is replaced by the month as a decimal number
(01-12).
</p></li><li class="listitem"><p>
<code class="literal">%n</code> - is replaced by a newline.
</p></li><li class="listitem"><p>
<code class="literal">%O*</code> - the same as <code class="literal">%E*</code>.
</p></li><li class="listitem"><p>
<code class="literal">%p</code> - is replaced by national representation of
either <span class="quote">“<span class="quote">ante meridiem</span>”</span> or <span class="quote">“<span class="quote">post meridiem</span>”</span> as appropriate.
</p></li><li class="listitem"><p>
<code class="literal">%R</code> - is equivalent to <code class="literal">%H:%M</code>.
</p></li><li class="listitem"><p>
<code class="literal">%r</code> - is equivalent to <code class="literal">%I:%M:%S
%p</code>.
</p></li><li class="listitem"><p>
<code class="literal">%S</code> - is replaced by the second as a decimal
number (00-60).
</p></li><li class="listitem"><p>
<code class="literal">%s</code> - is replaced by the number of seconds since
the Epoch, UTC.
</p></li><li class="listitem"><p>
<code class="literal">%T</code> - is equivalent to <code class="literal">%H:%M:%S</code>
</p></li><li class="listitem"><p>
<code class="literal">%t</code> - is replaced by a tab.
</p></li><li class="listitem"><p>
<code class="literal">%U</code> - is replaced by the week number of the year
(Sunday as the first day of the week) as a decimal number (00-53).
</p></li><li class="listitem"><p>
<code class="literal">%u</code> - is replaced by the weekday (Monday as the
first day of the week) as a decimal number (1-7).
</p></li><li class="listitem"><p>
<code class="literal">%V</code> - is replaced by the week number of the year
(Monday as the first day of the week) as a decimal number (01-53).
If the week containing January 1 has four or more days in the new
year, then it is week 1; otherwise it is the last week of the
previous year, and the next week is week 1.
</p></li><li class="listitem"><p>
<code class="literal">%v</code> - is equivalent to
<code class="literal">%e-%b-%Y</code>.
</p></li><li class="listitem"><p>
<code class="literal">%W</code> - is replaced by the week number of the year
(Monday as the first day of the week) as a decimal number (00-53).
</p></li><li class="listitem"><p>
<code class="literal">%w</code> - is replaced by the weekday (Sunday as the
first day of the week) as a decimal number (0-6).
</p></li><li class="listitem"><p>
<code class="literal">%X</code> - is replaced by national representation of
the time.
</p></li><li class="listitem"><p>
<code class="literal">%x</code> - is replaced by national representation of
the date.
</p></li><li class="listitem"><p>
<code class="literal">%Y</code> - is replaced by the year with century as a
decimal number.
</p></li><li class="listitem"><p>
<code class="literal">%y</code> - is replaced by the year without century as a
decimal number (00-99).
</p></li><li class="listitem"><p>
<code class="literal">%Z</code> - is replaced by the time zone name.
</p></li><li class="listitem"><p>
<code class="literal">%z</code> - is replaced by the time zone offset from
UTC; a leading plus sign stands for east of UTC, a minus sign for
west of UTC, hours and minutes follow with two digits each and no
delimiter between them (common form for RFC 822 date headers).
</p></li><li class="listitem"><p>
<code class="literal">%+</code> - is replaced by national representation of
the date and time.
</p></li><li class="listitem"><p>
<code class="literal">%-*</code> - GNU libc extension. Do not do any padding
when performing numerical outputs.
</p></li><li class="listitem"><p>
$_* - GNU libc extension. Explicitly specify space for padding.
</p></li><li class="listitem"><p>
<code class="literal">%0*</code> - GNU libc extension. Explicitly specify zero
for padding.
</p></li><li class="listitem"><p>
<code class="literal">%%</code> - is replaced by <code class="literal">%</code>.
</p></li></ul></div><p>
</p></dd><dt id="PGTYPESTIMESTAMPSUB"><span class="term"><code class="function">PGTYPEStimestamp_sub</code></span></dt><dd><p>
Subtract one timestamp from another one and save the result in a
variable of type interval.
</p><pre class="synopsis">
int PGTYPEStimestamp_sub(timestamp *ts1, timestamp *ts2, interval *iv);
</pre><p>
The function will subtract the timestamp variable that <code class="literal">ts2</code>
points to from the timestamp variable that <code class="literal">ts1</code> points to
and will store the result in the interval variable that <code class="literal">iv</code>
points to.
</p><p>
Upon success, the function returns 0 and a negative value if an
error occurred.
</p></dd><dt id="PGTYPESTIMESTAMPDEFMTASC"><span class="term"><code class="function">PGTYPEStimestamp_defmt_asc</code></span></dt><dd><p>
Parse a timestamp value from its textual representation using a
formatting mask.
</p><pre class="synopsis">
int PGTYPEStimestamp_defmt_asc(char *str, char *fmt, timestamp *d);
</pre><p>
The function receives the textual representation of a timestamp in the
variable <code class="literal">str</code> as well as the formatting mask to use in the
variable <code class="literal">fmt</code>. The result will be stored in the variable
that <code class="literal">d</code> points to.
</p><p>
If the formatting mask <code class="literal">fmt</code> is NULL, the function will fall
back to the default formatting mask which is <code class="literal">%Y-%m-%d
%H:%M:%S</code>.
</p><p>
This is the reverse function to <a class="xref" href="ecpg-pgtypes.html#PGTYPESTIMESTAMPFMTASC"><code class="function">PGTYPEStimestamp_fmt_asc</code></a>. See the documentation there in
order to find out about the possible formatting mask entries.
</p></dd><dt id="PGTYPESTIMESTAMPADDINTERVAL"><span class="term"><code class="function">PGTYPEStimestamp_add_interval</code></span></dt><dd><p>
Add an interval variable to a timestamp variable.
</p><pre class="synopsis">
int PGTYPEStimestamp_add_interval(timestamp *tin, interval *span, timestamp *tout);
</pre><p>
The function receives a pointer to a timestamp variable <code class="literal">tin</code>
and a pointer to an interval variable <code class="literal">span</code>. It adds the
interval to the timestamp and saves the resulting timestamp in the
variable that <code class="literal">tout</code> points to.
</p><p>
Upon success, the function returns 0 and a negative value if an
error occurred.
</p></dd><dt id="PGTYPESTIMESTAMPSUBINTERVAL"><span class="term"><code class="function">PGTYPEStimestamp_sub_interval</code></span></dt><dd><p>
Subtract an interval variable from a timestamp variable.
</p><pre class="synopsis">
int PGTYPEStimestamp_sub_interval(timestamp *tin, interval *span, timestamp *tout);
</pre><p>
The function subtracts the interval variable that <code class="literal">span</code>
points to from the timestamp variable that <code class="literal">tin</code> points to
and saves the result into the variable that <code class="literal">tout</code> points
to.
</p><p>
Upon success, the function returns 0 and a negative value if an
error occurred.
</p></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-INTERVAL"><div class="titlepage"><div><div><h3 class="title">36.6.5. The interval Type</h3></div></div></div><p>
The interval type in C enables your programs to deal with data of the SQL
type interval. See <a class="xref" href="datatype-datetime.html" title="8.5. Date/Time Types">Section 8.5</a> for the equivalent
type in the <span class="productname">PostgreSQL</span> server.
</p><p>
The following functions can be used to work with the interval type:
</p><div class="variablelist"><dl class="variablelist"><dt id="PGTYPESINTERVALNEW"><span class="term"><code class="function">PGTYPESinterval_new</code></span></dt><dd><p>
Return a pointer to a newly allocated interval variable.
</p><pre class="synopsis">
interval *PGTYPESinterval_new(void);
</pre><p>
</p></dd><dt id="PGTYPESINTERVALFREE"><span class="term"><code class="function">PGTYPESinterval_free</code></span></dt><dd><p>
Release the memory of a previously allocated interval variable.
</p><pre class="synopsis">
void PGTYPESinterval_new(interval *intvl);
</pre><p>
</p></dd><dt id="PGTYPESINTERVALFROMASC"><span class="term"><code class="function">PGTYPESinterval_from_asc</code></span></dt><dd><p>
Parse an interval from its textual representation.
</p><pre class="synopsis">
interval *PGTYPESinterval_from_asc(char *str, char **endptr);
</pre><p>
The function parses the input string <code class="literal">str</code> and returns a
pointer to an allocated interval variable.
At the moment ECPG always parses
the complete string and so it currently does not support to store the
address of the first invalid character in <code class="literal">*endptr</code>.
You can safely set <code class="literal">endptr</code> to NULL.
</p></dd><dt id="PGTYPESINTERVALTOASC"><span class="term"><code class="function">PGTYPESinterval_to_asc</code></span></dt><dd><p>
Convert a variable of type interval to its textual representation.
</p><pre class="synopsis">
char *PGTYPESinterval_to_asc(interval *span);
</pre><p>
The function converts the interval variable that <code class="literal">span</code>
points to into a C char*. The output looks like this example:
<code class="literal">@ 1 day 12 hours 59 mins 10 secs</code>.
The result must be freed with <code class="function">PGTYPESchar_free()</code>.
</p></dd><dt id="PGTYPESINTERVALCOPY"><span class="term"><code class="function">PGTYPESinterval_copy</code></span></dt><dd><p>
Copy a variable of type interval.
</p><pre class="synopsis">
int PGTYPESinterval_copy(interval *intvlsrc, interval *intvldest);
</pre><p>
The function copies the interval variable that <code class="literal">intvlsrc</code>
points to into the variable that <code class="literal">intvldest</code> points to. Note
that you need to allocate the memory for the destination variable
before.
</p></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-DECIMAL"><div class="titlepage"><div><div><h3 class="title">36.6.6. The decimal Type</h3></div></div></div><p>
The decimal type is similar to the numeric type. However it is limited to
a maximum precision of 30 significant digits. In contrast to the numeric
type which can be created on the heap only, the decimal type can be
created either on the stack or on the heap (by means of the functions
<code class="function">PGTYPESdecimal_new</code> and
<code class="function">PGTYPESdecimal_free</code>).
There are a lot of other functions that deal with the decimal type in the
<span class="productname">Informix</span> compatibility mode described in <a class="xref" href="ecpg-informix-compat.html" title="36.15. Informix Compatibility Mode">Section 36.15</a>.
</p><p>
The following functions can be used to work with the decimal type and are
not only contained in the <code class="literal">libcompat</code> library.
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="function">PGTYPESdecimal_new</code></span></dt><dd><p>
Request a pointer to a newly allocated decimal variable.
</p><pre class="synopsis">
decimal *PGTYPESdecimal_new(void);
</pre><p>
</p></dd><dt><span class="term"><code class="function">PGTYPESdecimal_free</code></span></dt><dd><p>
Free a decimal type, release all of its memory.
</p><pre class="synopsis">
void PGTYPESdecimal_free(decimal *var);
</pre><p>
</p></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-ERRNO"><div class="titlepage"><div><div><h3 class="title">36.6.7. errno Values of pgtypeslib</h3></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">PGTYPES_NUM_BAD_NUMERIC</code></span></dt><dd><p>
An argument should contain a numeric variable (or point to a numeric
variable) but in fact its in-memory representation was invalid.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_NUM_OVERFLOW</code></span></dt><dd><p>
An overflow occurred. Since the numeric type can deal with almost
arbitrary precision, converting a numeric variable into other types
might cause overflow.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_NUM_UNDERFLOW</code></span></dt><dd><p>
An underflow occurred. Since the numeric type can deal with almost
arbitrary precision, converting a numeric variable into other types
might cause underflow.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_NUM_DIVIDE_ZERO</code></span></dt><dd><p>
A division by zero has been attempted.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_BAD_DATE</code></span></dt><dd><p>
An invalid date string was passed to
the <code class="function">PGTYPESdate_from_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_ERR_EARGS</code></span></dt><dd><p>
Invalid arguments were passed to the
<code class="function">PGTYPESdate_defmt_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_ERR_ENOSHORTDATE</code></span></dt><dd><p>
An invalid token in the input string was found by the
<code class="function">PGTYPESdate_defmt_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_INTVL_BAD_INTERVAL</code></span></dt><dd><p>
An invalid interval string was passed to the
<code class="function">PGTYPESinterval_from_asc</code> function, or an
invalid interval value was passed to the
<code class="function">PGTYPESinterval_to_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_ERR_ENOTDMY</code></span></dt><dd><p>
There was a mismatch in the day/month/year assignment in the
<code class="function">PGTYPESdate_defmt_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_BAD_DAY</code></span></dt><dd><p>
An invalid day of the month value was found by
the <code class="function">PGTYPESdate_defmt_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_DATE_BAD_MONTH</code></span></dt><dd><p>
An invalid month value was found by
the <code class="function">PGTYPESdate_defmt_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_TS_BAD_TIMESTAMP</code></span></dt><dd><p>
An invalid timestamp string pass passed to
the <code class="function">PGTYPEStimestamp_from_asc</code> function,
or an invalid timestamp value was passed to
the <code class="function">PGTYPEStimestamp_to_asc</code> function.
</p></dd><dt><span class="term"><code class="literal">PGTYPES_TS_ERR_EINFTIME</code></span></dt><dd><p>
An infinite timestamp value was encountered in a context that
cannot handle it.
</p></dd></dl></div><p>
</p></div><div class="sect2" id="ECPG-PGTYPES-CONSTANTS"><div class="titlepage"><div><div><h3 class="title">36.6.8. Special Constants of pgtypeslib</h3></div></div></div><p>
</p><div class="variablelist"><dl class="variablelist"><dt id="PGTYPESINVALIDTIMESTAMP"><span class="term"><code class="literal">PGTYPESInvalidTimestamp</code></span></dt><dd><p>
A value of type timestamp representing an invalid time stamp. This is
returned by the function <code class="function">PGTYPEStimestamp_from_asc</code> on
parse error.
Note that due to the internal representation of the <code class="type">timestamp</code> data type,
<code class="literal">PGTYPESInvalidTimestamp</code> is also a valid timestamp at
the same time. It is set to <code class="literal">1899-12-31 23:59:59</code>. In order
to detect errors, make sure that your application does not only test
for <code class="literal">PGTYPESInvalidTimestamp</code> but also for
<code class="literal">errno != 0</code> after each call to
<code class="function">PGTYPEStimestamp_from_asc</code>.
</p></dd></dl></div><p>
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