에러가 나요 ㅠㅠ

select wr_id, wr_datetime, wr_3, wr_4, wr_5, wr_6, wr_7, wr_8, wr_16 from g4_write_miz04_01 where mb_id = 'admin' and substr(wr_datetime,1,10)>='2011-02-17' order by wr_id desc

1064 : You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '(wr_datetime,1,10)>='2011-02-17' order by wr_id desc' at line 1

error file : /admin/bbs/write_online.php


라고 에러가 나오는데요 ㅠㅠ

<?
$bo_table_00 = "miz04_01";
$f_date00_00 = $f_date00-7;
$f_year00_00 = substr($f_date00_00,0,4);
$f_mon00_00 = substr($f_date00_00,4,2);
$f_day00_00 = substr($f_date00_00,6,2);
$f_date00_01 = $f_year00_00."-".sprintf("%02d",$f_mon00_00)."-".$f_day00_00;

$sql = " select wr_id, wr_datetime, wr_3, wr_4, wr_5, wr_6, wr_7, wr_8, wr_16 from $g4[write_prefix]$bo_table_00 where mb_id = '$member[mb_id]' and substr(wr_datetime,1,10)>='$f_date00_01' order by wr_id desc";
$result = sql_query($sql);
$total_count = mysql_num_rows($result);
if($total_count) {
?>

이부분이 잘못된거는 같은데 어디가 잘못된건지 ㅠㅠ