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   2 <!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>35.52. table_constraints</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-sql-sizing.html" title="35.51. sql_sizing" /><link rel="next" href="infoschema-table-privileges.html" title="35.53. table_privileges" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">35.52. <code class="literal">table_constraints</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="infoschema-sql-sizing.html" title="35.51. sql_sizing">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="information-schema.html" title="Chapter 35. The Information Schema">Up</a></td><th width="60%" align="center">Chapter 35. The Information Schema</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="infoschema-table-privileges.html" title="35.53. table_privileges">Next</a></td></tr></table><hr /></div><div class="sect1" id="INFOSCHEMA-TABLE-CONSTRAINTS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">35.52. <code class="literal">table_constraints</code> <a href="#INFOSCHEMA-TABLE-CONSTRAINTS" class="id_link">#</a></h2></div></div></div><p>
   3    The view <code class="literal">table_constraints</code> contains all
   4    constraints belonging to tables that the current user owns or has
   5    some privilege other than <code class="literal">SELECT</code> on.
   6   </p><div class="table" id="id-1.7.6.56.3"><p class="title"><strong>Table 35.50. <code class="structname">table_constraints</code> Columns</strong></p><div class="table-contents"><table class="table" summary="table_constraints Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition">
   7        Column Type
   8       </p>
   9       <p>
  10        Description
  11       </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition">
  12        <code class="structfield">constraint_catalog</code> <code class="type">sql_identifier</code>
  13       </p>
  14       <p>
  15        Name of the database that contains the constraint (always the current database)
  16       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  17        <code class="structfield">constraint_schema</code> <code class="type">sql_identifier</code>
  18       </p>
  19       <p>
  20        Name of the schema that contains the constraint
  21       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  22        <code class="structfield">constraint_name</code> <code class="type">sql_identifier</code>
  23       </p>
  24       <p>
  25        Name of the constraint
  26       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  27        <code class="structfield">table_catalog</code> <code class="type">sql_identifier</code>
  28       </p>
  29       <p>
  30        Name of the database that contains the table (always the current database)
  31       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  32        <code class="structfield">table_schema</code> <code class="type">sql_identifier</code>
  33       </p>
  34       <p>
  35        Name of the schema that contains the table
  36       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  37        <code class="structfield">table_name</code> <code class="type">sql_identifier</code>
  38       </p>
  39       <p>
  40        Name of the table
  41       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  42        <code class="structfield">constraint_type</code> <code class="type">character_data</code>
  43       </p>
  44       <p>
  45        Type of the constraint: <code class="literal">CHECK</code> (includes not-null constraints),
  46        <code class="literal">FOREIGN KEY</code>, <code class="literal">PRIMARY KEY</code>,
  47        or <code class="literal">UNIQUE</code>
  48       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  49        <code class="structfield">is_deferrable</code> <code class="type">yes_or_no</code>
  50       </p>
  51       <p>
  52        <code class="literal">YES</code> if the constraint is deferrable, <code class="literal">NO</code> if not
  53       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  54        <code class="structfield">initially_deferred</code> <code class="type">yes_or_no</code>
  55       </p>
  56       <p>
  57        <code class="literal">YES</code> if the constraint is deferrable and initially deferred, <code class="literal">NO</code> if not
  58       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  59        <code class="structfield">enforced</code> <code class="type">yes_or_no</code>
  60       </p>
  61       <p>
  62        <code class="literal">YES</code> if the constraint is enforced, <code class="literal">NO</code> if not
  63       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  64        <code class="structfield">nulls_distinct</code> <code class="type">yes_or_no</code>
  65       </p>
  66       <p>
  67        If the constraint is a unique constraint, then <code class="literal">YES</code>
  68        if the constraint treats nulls as distinct or <code class="literal">NO</code> if
  69        it treats nulls as not distinct, otherwise null for other types of
  70        constraints.
  71       </p></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-sql-sizing.html" title="35.51. sql_sizing">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="information-schema.html" title="Chapter 35. The Information Schema">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="infoschema-table-privileges.html" title="35.53. table_privileges">Next</a></td></tr><tr><td width="40%" align="left" valign="top">35.51. <code class="literal">sql_sizing</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 35.53. <code class="literal">table_privileges</code></td></tr></table></div></body></html>