It's in PHP 3 and 4.

Egon Schmid · Egon Schmid · commit b64eaf737b05 · 1999-07-19T20:09:05.000Z
diff --git a/ext/mysql/mysql.c b/ext/mysql/mysql.c
@@ -1472,7 +1472,7 @@ PHP_FUNCTION(mysql_fetch_row)
 /* }}} */
 
 
-/* {{{ proto object mysql_fetch_object(int result)
+/* {{{ proto object mysql_fetch_object(int result [, int result_type])
    Fetch a result row as an object */
 PHP_FUNCTION(mysql_fetch_object)
 {
@@ -1486,7 +1486,7 @@ PHP_FUNCTION(mysql_fetch_object)
 /* }}} */
 
 
-/* {{{ proto array mysql_fetch_array(int result)
+/* {{{ proto array mysql_fetch_array(int result [, int result_type])
    Fetch a result row as an associative array */
 PHP_FUNCTION(mysql_fetch_array)
 {

Original file line number	Diff line number	Diff line change
`@@ -1472,7 +1472,7 @@ PHP_FUNCTION(mysql_fetch_row)`
`1472`	`1472`	`/* }}} */`
`1473`	`1473`
`1474`	`1474`
`1475`		`-/* {{{ proto object mysql_fetch_object(int result)`
	`1475`	`+/* {{{ proto object mysql_fetch_object(int result [, int result_type])`
`1476`	`1476`	`Fetch a result row as an object */`
`1477`	`1477`	`PHP_FUNCTION(mysql_fetch_object)`
`1478`	`1478`	`{`
`@@ -1486,7 +1486,7 @@ PHP_FUNCTION(mysql_fetch_object)`
`1486`	`1486`	`/* }}} */`
`1487`	`1487`
`1488`	`1488`
`1489`		`-/* {{{ proto array mysql_fetch_array(int result)`
	`1489`	`+/* {{{ proto array mysql_fetch_array(int result [, int result_type])`
`1490`	`1490`	`Fetch a result row as an associative array */`
`1491`	`1491`	`PHP_FUNCTION(mysql_fetch_array)`
`1492`	`1492`	`{`