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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>37.17. constraint_column_usage</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="infoschema-columns.html" title="37.16. columns" /><link rel="next" href="infoschema-constraint-table-usage.html" title="37.18. constraint_table_usage" /></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">37.17. <code xmlns="http://www.w3.org/1999/xhtml" class="literal">constraint_column_usage</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="infoschema-columns.html" title="37.16. columns">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="information-schema.html" title="Chapter 37. The Information Schema">Up</a></td><th width="60%" align="center">Chapter 37. The Information Schema</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="infoschema-constraint-table-usage.html" title="37.18. constraint_table_usage">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="INFOSCHEMA-CONSTRAINT-COLUMN-USAGE"><div class="titlepage"><div><div><h2 class="title" style="clear: both">37.17. <code class="literal">constraint_column_usage</code></h2></div></div></div><p>
The view <code class="literal">constraint_column_usage</code> identifies all
columns in the current database that are used by some constraint.
Only those columns are shown that are contained in a table owned by
a currently enabled role. For a check constraint, this view
identifies the columns that are used in the check expression. For
a foreign key constraint, this view identifies the columns that the
foreign key references. For a unique or primary key constraint,
this view identifies the constrained columns.
</p><div class="table" id="id-1.7.6.21.3"><p class="title"><strong>Table 37.15. <code class="literal">constraint_column_usage</code> Columns</strong></p><div class="table-contents"><table class="table" summary="constraint_column_usage Columns" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Name</th><th>Data Type</th><th>Description</th></tr></thead><tbody><tr><td><code class="literal">table_catalog</code></td><td><code class="type">sql_identifier</code></td><td>
Name of the database that contains the table that contains the
column that is used by some constraint (always the current
database)
</td></tr><tr><td><code class="literal">table_schema</code></td><td><code class="type">sql_identifier</code></td><td>
Name of the schema that contains the table that contains the
column that is used by some constraint
</td></tr><tr><td><code class="literal">table_name</code></td><td><code class="type">sql_identifier</code></td><td>
Name of the table that contains the column that is used by some
constraint
</td></tr><tr><td><code class="literal">column_name</code></td><td><code class="type">sql_identifier</code></td><td>
Name of the column that is used by some constraint
</td></tr><tr><td><code class="literal">constraint_catalog</code></td><td><code class="type">sql_identifier</code></td><td>Name of the database that contains the constraint (always the current database)</td></tr><tr><td><code class="literal">constraint_schema</code></td><td><code class="type">sql_identifier</code></td><td>Name of the schema that contains the constraint</td></tr><tr><td><code class="literal">constraint_name</code></td><td><code class="type">sql_identifier</code></td><td>Name of the constraint</td></tr></tbody></table></div></div><br class="table-break" /></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="infoschema-columns.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="information-schema.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="infoschema-constraint-table-usage.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">37.16. <code class="literal">columns</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 37.18. <code class="literal">constraint_table_usage</code></td></tr></table></div></body></html>
