Sophie: postgresql-docs-7.3.2-5mdk ppc

postgresql-docs-7.3.2-5mdk.ppc.rpm

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>PostgreSQL 7.3.2 Documentation</TH
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><H1
><A
NAME="ECPG"
>Chapter 4. <SPAN
CLASS="APPLICATION"
>ECPG</SPAN
> - Embedded <SPAN
CLASS="ACRONYM"
>SQL</SPAN
> in C</A
></H1
><DIV
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><B
>Table of Contents</B
></DT
><DT
>4.1. <A
HREF="ecpg.html#ECPG-CONCEPT"
>The Concept</A
></DT
><DT
>4.2. <A
HREF="ecpg-connect.html"
>Connecting to the Database Server</A
></DT
><DT
>4.3. <A
HREF="ecpg-disconnect.html"
>Closing a Connection</A
></DT
><DT
>4.4. <A
HREF="ecpg-commands.html"
>Running SQL Commands</A
></DT
><DT
>4.5. <A
HREF="ecpg-variables.html"
>Passing Data</A
></DT
><DT
>4.6. <A
HREF="ecpg-errors.html"
>Error Handling</A
></DT
><DT
>4.7. <A
HREF="ecpg-include.html"
>Including Files</A
></DT
><DT
>4.8. <A
HREF="ecpg-process.html"
>Processing Embedded SQL Programs</A
></DT
><DT
>4.9. <A
HREF="ecpg-library.html"
>Library Functions</A
></DT
><DT
>4.10. <A
HREF="ecpg-porting.html"
>Porting From Other <SPAN
CLASS="ACRONYM"
>RDBMS</SPAN
> Packages</A
></DT
><DT
>4.11. <A
HREF="ecpg-develop.html"
>For the Developer</A
></DT
><DD
><DL
><DT
>4.11.1. <A
HREF="ecpg-develop.html#AEN27919"
>The Preprocessor</A
></DT
><DT
>4.11.2. <A
HREF="ecpg-develop.html#AEN27964"
>The Library</A
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><P
>  This chapter describes the embedded <SPAN
CLASS="ACRONYM"
>SQL</SPAN
> package
  for <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>. It works with
  <SPAN
CLASS="ACRONYM"
>C</SPAN
> and <SPAN
CLASS="ACRONYM"
>C++</SPAN
>. It was written by
  Linus Tolke (<TT
CLASS="EMAIL"
>&#60;<A
HREF="mailto:linus@epact.se"
>linus@epact.se</A
>&#62;</TT
>) and Michael Meskes
  (<TT
CLASS="EMAIL"
>&#60;<A
HREF="mailto:meskes@postgresql.org"
>meskes@postgresql.org</A
>&#62;</TT
>).
 </P
><P
>  Admittedly, this documentation is quite incomplete.  But since this
  interface is standardized, additional information can be found in
  many resources about SQL.
 </P
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="ECPG-CONCEPT"
>4.1. The Concept</A
></H1
><P
>   An embedded SQL program consists of code written in an ordinary
   programming language, in this case C, mixed with SQL commands in
   specially marked sections.  To build the program, the source code
   is first passed to the embedded SQL preprocessor, which converts it
   to an ordinary C program, and afterwards it can be processed by a C
   compilation tool chain.
  </P
><P
>   Embedded <SPAN
CLASS="ACRONYM"
>SQL</SPAN
> has advantages over other methods
   for handling <SPAN
CLASS="ACRONYM"
>SQL</SPAN
> commands from C code. First, it
   takes care of the tedious passing of information to and from
   variables in your <SPAN
CLASS="ACRONYM"
>C</SPAN
> program.  Secondly, embedded
   SQL in C is defined in the SQL standard and supported by many other
   SQL databases.  The PostgreSQL implementation is designed to match
   this standard as much as possible, and it is usually possible to
   port embedded <SPAN
CLASS="ACRONYM"
>SQL</SPAN
> programs written for other
   <SPAN
CLASS="ACRONYM"
>RDBMS</SPAN
> to <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
   with relative ease.
  </P
><P
>   As indicated, programs written for the embedded SQL interface are
   normal C programs with special code inserted to perform
   database-related actions.  This special code always has the form
</P><PRE
CLASS="PROGRAMLISTING"
>EXEC SQL ...;</PRE
><P>
   These statements syntactically take the place of a C statement.
   Depending on the particular statement, they may appear in the
   global context or within a function.  Embedded SQL statements
   follow the case-sensitivity rules of normal SQL code, and not those
   of C.
  </P
><P
>   The following sections explain all the embedded SQL statements.
  </P
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