role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>quote_literal</primary>
        </indexterm>
        <function>quote_literal</function> ( <type>text</type> )
        <returnvalue>text</returnvalue>
       </para>
       <para>
        Returns the given string suitably quoted to be used as a string literal
        in an <acronym>SQL</acronym> statement string.
        Embedded single-quotes and backslashes are properly doubled.
        Note that <function>quote_literal</function> returns null on null
        input; if the argument might be null,
        <function>quote_nullable</function> is often more suitable.
        See also <xref linkend="plpgsql-quote-literal-example"/>.
       </para>
       <para>
        <literal>quote_literal(E'O\'Reilly')</literal>
        <returnvalue>'O''Reilly'</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>quote_literal</function> ( <type>anyelement</type> )
        <returnvalue>text</returnvalue>
       </para>
       <para>
        Converts the given value to text and then quotes it as a literal.
        Embedded single-quotes and backslashes are properly doubled.
       </para>
       <para>
        <literal>quote_literal(42.5)</literal>
        <returnvalue>'42.5'</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>quote_nullable</primary>
        </indexterm>
        <function>quote_nullable</function> ( <type>text</type> )
        <returnvalue>text</returnvalue>
       </para>
       <para>
        Returns the given string suitably quoted to be used as a string literal
        in an <acronym>SQL</acronym> statement string; or, if the argument
        is null, returns <literal>NULL</literal>.
        Embedded single-quotes and backslashes are properly doubled.
        See also <xref linkend="plpgsql-quote-literal-example"/>.
       </para>
       <para>
        <literal>quote_nullable(NULL)</literal>
        <returnvalue>NULL</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <function>quote_nullable</function> ( <type>anyelement</type> )
        <returnvalue>text</returnvalue>
       </para>
       <para>
        Converts the given value to text and then quotes it as a literal;
        or, if the argument is null, returns <literal>NULL</literal>.
        Embedded single-quotes and backslashes are properly doubled.
       </para>
       <para>
        <literal>quote_nullable(42.5)</literal>
        <returnvalue>'42.5'</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>regexp_count</primary>
        </indexterm>
        <function>regexp_count</function> ( <parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter> <type>text</type>
         <optional>, <parameter>start</parameter> <type>integer</type>
         <optional>, <parameter>flags</parameter> <type>text</type> </optional> </optional> )
        <returnvalue>integer</returnvalue>
       </para>
       <para>
        Returns the number of times the POSIX regular
        expression <parameter>pattern</parameter> matches in
        the <parameter>string</parameter>; see
        <xref linkend="functions-posix-regexp"/>.
       </para>
       <para>
        <literal>regexp_count('123456789012', '\d\d\d', 2)</literal>
        <returnvalue>3</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>regexp_instr</primary>
        </indexterm>
        <function>regexp_instr</function> ( <parameter>string</parameter> <type>text</type>, <parameter>pattern</parameter>