报表-php读取数据库报错，读取不出来（附源代码

提示错误：

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\yxweb\yjjh\B\dis_ck.php on line 47

起没查询前期报表

源码：
date_default_timezone_set('Asia/Shanghai');//Asia/Shanghai
$sj=date("Y-m-d");//取前期
//echo $sj;
$gq=0;
$bb=0;
if(!empty($_POST['sj'])){
$sj=$_POST['sj'];
//$sj="$sj[6]"."$sj[7]"."$sj[8]"."$sj[9]"."-"."$sj[0]"."$sj[1]"."-"."$sj[3]"."$sj[4]";
}
if(!empty($_POST['gq'])){
$gq=$_POST['gq'];
}
if(!empty($_POST['bb'])){
$bb=$_POST['bb'];
}
//echo"

$sj, $gq, ";
$sql=mysql_query("select * from $bb where gq='$gq' and sj like'$sj%' order by id desc ");
$info=mysql_fetch_array($sql);
if($info==false){

//echo"

$array

echo "

起没查询前期报表