<?

$conn=@mssql_connect("MDMQBJPPC43VP31","sa","12345");

mssql_select_db("huanban",$conn);  
$a='a';

$rs3=mssql_query("select *  from ceshi where ceshi=$a   ",$conn);
while($row3=mssql_fetch_array($rs3))
{

echo $row3[0] ;

}

?>

为什么这样不行？  如果把$a直接换成'a'就可以呢？

Warning: mssql_query() [function.mssql-query]: message: ���� 'a' ���� (severity 16) in D:\PHPnow-1.5.6\htdocs\123.php on line 8

Warning: mssql_query() [function.mssql-query]: Query failed in D:\PHPnow-1.5.6\htdocs\123.php on line 8

Warning: mssql_fetch_array(): supplied argument is not a valid MS SQL-result resource in D:\PHPnow-1.5.6\htdocs\123.php on line 9


报错是这样的，好像字符串赋值出了问题。