Function exec_stmt_forc

src/pl/plpgsql/src/pl_exec.c:2811–2936

---------- * exec_stmt_forc Execute a loop for each row from a cursor. * ---------- */

 * ----------
 */
static int
exec_stmt_forc(PLpgSQL_execstate *estate, PLpgSQL_stmt_forc *stmt)
{
	PLpgSQL_var *curvar;
	MemoryContext stmt_mcontext = NULL;
	char	   *curname = NULL;
	PLpgSQL_expr *query;
	ParamListInfo paramLI;
	Portal		portal;
	int			rc;

	/* ----------
	 * Get the cursor variable and if it has an assigned name, check
	 * that it's not in use currently.
	 * ----------
	 */
	curvar = (PLpgSQL_var *) (estate->datums[stmt->curvar]);
	if (!curvar->isnull)
	{
		MemoryContext oldcontext;

		/* We only need stmt_mcontext to hold the cursor name string */
		stmt_mcontext = get_stmt_mcontext(estate);
		oldcontext = MemoryContextSwitchTo(stmt_mcontext);
		curname = TextDatumGetCString(curvar->value);
		MemoryContextSwitchTo(oldcontext);

		if (SPI_cursor_find(curname) != NULL)
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_CURSOR),
					 errmsg("cursor \"%s\" already in use", curname)));
	}

	/* ----------
	 * Open the cursor just like an OPEN command
	 *
	 * Note: parser should already have checked that statement supplies
	 * args iff cursor needs them, but we check again to be safe.
	 * ----------
	 */
	if (stmt->argquery != NULL)
	{
		/* ----------
		 * OPEN CURSOR with args.  We fake a SELECT ... INTO ...
		 * statement to evaluate the args and put 'em into the
		 * internal row.
		 * ----------
		 */
		PLpgSQL_stmt_execsql set_args;

		if (curvar->cursor_explicit_argrow < 0)
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("arguments given for cursor without arguments")));

		memset(&set_args, 0, sizeof(set_args));
		set_args.cmd_type = PLPGSQL_STMT_EXECSQL;
		set_args.lineno = stmt->lineno;