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16th chunk of `doc/src/sgml/spi.sgml`
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<refentry id="spi-spi-getargcount">
 <indexterm><primary>SPI_getargcount</primary></indexterm>

 <refmeta>
  <refentrytitle>SPI_getargcount</refentrytitle>
  <manvolnum>3</manvolnum>
 </refmeta>

 <refnamediv>
  <refname>SPI_getargcount</refname>
  <refpurpose>return the number of arguments needed by a statement
  prepared by <function>SPI_prepare</function></refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
int SPI_getargcount(SPIPlanPtr <parameter>plan</parameter>)
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <function>SPI_getargcount</function> returns the number of arguments needed
   to execute a statement prepared by <function>SPI_prepare</function>.
  </para>
 </refsect1>

 <refsect1>
  <title>Arguments</title>

  <variablelist>
   <varlistentry>
    <term><literal>SPIPlanPtr <parameter>plan</parameter></literal></term>
    <listitem>
     <para>
      prepared statement (returned by <function>SPI_prepare</function>)
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Return Value</title>
  <para>
    The count of expected arguments for the <parameter>plan</parameter>.
    If the <parameter>plan</parameter> is <symbol>NULL</symbol> or invalid,
    <varname>SPI_result</varname> is set to <symbol>SPI_ERROR_ARGUMENT</symbol>
    and -1 is returned.
  </para>
 </refsect1>
</refentry>

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<refentry id="spi-spi-getargtypeid">
 <indexterm><primary>SPI_getargtypeid</primary></indexterm>

 <refmeta>
  <refentrytitle>SPI_getargtypeid</refentrytitle>
  <manvolnum>3</manvolnum>
 </refmeta>

 <refnamediv>
  <refname>SPI_getargtypeid</refname>
  <refpurpose>return the data type OID for an argument of
  a statement prepared by <function>SPI_prepare</function></refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
Oid SPI_getargtypeid(SPIPlanPtr <parameter>plan</parameter>, int <parameter>argIndex</parameter>)
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <function>SPI_getargtypeid</function> returns the OID representing the type
   for the <parameter>argIndex</parameter>'th argument of a statement prepared by
   <function>SPI_prepare</function>. First argument is at index zero.
  </para>
 </refsect1>

 <refsect1>
  <title>Arguments</title>

  <variablelist>
   <varlistentry>
    <term><literal>SPIPlanPtr <parameter>plan</parameter></literal></term>
    <listitem>
     <para>
      prepared statement (returned by <function>SPI_prepare</function>)
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>int <parameter>argIndex</parameter></literal></term>
    <listitem>
     <para>
      zero based index of the argument
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Return Value</title>
  <para>
    The type OID of the argument at the given index.
    If the <parameter>plan</parameter> is <symbol>NULL</symbol> or invalid,
    or <parameter>argIndex</parameter> is less than 0 or
    not less than the number of arguments declared for the
    <parameter>plan</parameter>,
    <varname>SPI_result</varname> is set to <symbol>SPI_ERROR_ARGUMENT</symbol>
    and <symbol>InvalidOid</symbol> is returned.
  </para>
 </refsect1>
</refentry>

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<refentry id="spi-spi-is-cursor-plan">
 <indexterm><primary>SPI_is_cursor_plan</primary></indexterm>

 <refmeta>
  <refentrytitle>SPI_is_cursor_plan</refentrytitle>
  <manvolnum>3</manvolnum>
 </refmeta>

 <refnamediv>
  <refname>SPI_is_cursor_plan</refname>
  <refpurpose>return <symbol>true</symbol> if a statement
  prepared by <function>SPI_prepare</function> can be used with
  <function>SPI_cursor_open</function></refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
bool SPI_is_cursor_plan(SPIPlanPtr <parameter>plan</parameter>)
Title: SPI_getargcount and SPI_getargtypeid: Functions to Inspect Prepared Statements
Summary
This section describes two functions for retrieving information about prepared statements: `SPI_getargcount`, which returns the number of arguments needed by a statement prepared with `SPI_prepare`, and `SPI_getargtypeid`, which returns the OID of the data type for a specific argument of a prepared statement. Both functions take a `SPIPlanPtr` as input, representing the prepared statement. `SPI_getargcount` returns -1 and sets `SPI_result` to `SPI_ERROR_ARGUMENT` if the plan is invalid. `SPI_getargtypeid` returns `InvalidOid` and sets `SPI_result` to `SPI_ERROR_ARGUMENT` if the plan is invalid or the argument index is out of bounds.