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    <div>
     <h3 class="title">
      <a name="information-schema-referential-constraints-table">
      </a>
      28.3.25 The INFORMATION_SCHEMA REFERENTIAL_CONSTRAINTS Table
     </h3>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045079042272">
  </a>
  <p>
   The
   <a class="link" href="information-schema-referential-constraints-table.html" title="28.3.25 The INFORMATION_SCHEMA REFERENTIAL_CONSTRAINTS Table">
    <code class="literal">
     REFERENTIAL_CONSTRAINTS
    </code>
   </a>
   table
      provides information about foreign keys.
  </p>
  <p>
   The
   <a class="link" href="information-schema-referential-constraints-table.html" title="28.3.25 The INFORMATION_SCHEMA REFERENTIAL_CONSTRAINTS Table">
    <code class="literal">
     REFERENTIAL_CONSTRAINTS
    </code>
   </a>
   table has
      these columns:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <code class="literal">
       CONSTRAINT_CATALOG
      </code>
     </p>
     <p>
      The name of the catalog to which the constraint belongs. This
          value is always
      <code class="literal">
       def
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       CONSTRAINT_SCHEMA
      </code>
     </p>
     <p>
      The name of the schema (database) to which the constraint
          belongs.
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       CONSTRAINT_NAME
      </code>
     </p>
     <p>
      The name of the constraint.
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       UNIQUE_CONSTRAINT_CATALOG
      </code>
     </p>
     <p>
      The name of the catalog containing the unique constraint that
          the constraint references. This value is always
      <code class="literal">
       def
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       UNIQUE_CONSTRAINT_SCHEMA
      </code>
     </p>
     <p>
      The name of the schema containing the unique constraint that
          the constraint references.
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       UNIQUE_CONSTRAINT_NAME
      </code>
     </p>
     <p>
      The name of the unique constraint that the constraint
          references.
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       MATCH_OPTION
      </code>
     </p>
     <p>
      The value of the constraint
      <code class="literal">
       MATCH
      </code>
      attribute. The only valid value at this time is
      <code class="literal">
       NONE
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       UPDATE_RULE
      </code>
     </p>
     <p>
      The value of the constraint
      <code class="literal">
       ON UPDATE
      </code>
      attribute. The possible values are
      <code class="literal">
       CASCADE
      </code>
      ,
      <code class="literal">
       SET NULL
      </code>
      ,
      <code class="literal">
       SET DEFAULT
      </code>
      ,
      <code class="literal">
       RESTRICT
      </code>
      ,
      <code class="literal">
       NO ACTION
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       DELETE_RULE
      </code>
     </p>
     <p>
      The value of the constraint
      <code class="literal">
       ON DELETE
      </code>
      attribute. The possible values are
      <code class="literal">
       CASCADE
      </code>
      ,
      <code class="literal">
       SET NULL
      </code>
      ,
      <code class="literal">
       SET DEFAULT
      </code>
      ,
      <code class="literal">
       RESTRICT
      </code>
      ,
      <code class="literal">
       NO ACTION
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       TABLE_NAME
      </code>
     </p>
     <p>
      The name of the table. This value is the same as in the
      <a class="link" href="information-schema-table-constraints-table.html" title="28.3.41 The INFORMATION_SCHEMA TABLE_CONSTRAINTS Table">
       <code class="literal">
        TABLE_CONSTRAINTS
       </code>
      </a>
      table.
     </p>
    </li>
    <li class="listitem">
     <p>
      <code class="literal">
       REFERENCED_TABLE_NAME
      </code>
     </p>
     <p>
      The name of the table referenced by the constraint.
     </p>
    </li>
   </ul>
  </div>
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