从mysql获取数据显示空字符串[关闭]

Question

I fetch data from mysql and convert it to JSON but receive an empty array as a result: []

I want to select all data where category=given variable:

$flu = $_POST['searchCode'];
$query = mysql_query("SELECT * From catalog_Master WHERE  category='%$flu%'");

$rows = array();
while($row = mysql_fetch_assoc($query)) {
    $rows[] = $row;
}
echo json_encode($rows);

Answer 1

For % to work in MySQL, you need LIKE:

$query=mysql_query("SELECT * From catalog_Master WHERE category LIKE '%$flu%'");

You can also match beginning or end:

$query=mysql_query("SELECT * From catalog_Master WHERE category LIKE '$flu%'");
$query=mysql_query("SELECT * From catalog_Master WHERE category LIKE '%$flu'");

If you want exact matches, lose the % and the LIKE:

$query=mysql_query("SELECT * From catalog_Master WHERE category='$flu'");

Also, you should validate your $_POST variables (at least use mysql_real_escape_string, better use mysqli or PDO).