如果mysql中的if子句选择
问题描述：
My full query is:
$sql = "SELECT vehicle_id, fuel_type, gearbox_type, door_type, engine_package_name, FORMAT(engine_cap, 1)engine_cap, engine_power, FORMAT(fuel_cons, 1)fuel_cons, FORMAT(std_price, 0)std_price
FROM vehicle
WHERE model_id = '$model_id'
AND fuel_type IN ('$fuel_type1', '$fuel_type2', '$fuel_type3', '$fuel_type4') AND gearbox_type IN( '$gearbox_type1', '$gearbox_type2', '$gearbox_type3', '$gearbox_type4') AND door_type IN ('$door_type1', '$door_type2', '$door_type3', '$door_type4')" ;
I would like to skip the part of the query shown below if $fuel_type1 equals to zero.
AND fuel_type IN ('$fuel_type1', '$fuel_type2', '$fuel_type3', '$fuel_type4')
I have tried
$sql = "SELECT vehicle_id, fuel_type, gearbox_type, door_type, engine_package_name, FORMAT(engine_cap, 1)engine_cap, engine_power, FORMAT(fuel_cons, 1)fuel_cons, FORMAT(std_price, 0)std_price
FROM vehicle
WHERE model_id = '$model_id' ";
if($fuel_type1 != 0)
{
$sql += “ AND fuel_type IN ('$fuel_type1', '$fuel_type2', '$fuel_type3', '$fuel_type4')”;
}
didn't worked.
Also I have tried
$sql = "SELECT vehicle_id, fuel_type, gearbox_type, door_type, engine_package_name, FORMAT(engine_cap, 1)engine_cap, engine_power, FORMAT(fuel_cons, 1)fuel_cons, FORMAT(std_price, 0)std_price
FROM vehicle
WHERE model_id='$model_id’
AND IF($fuel_type1 <> 0,'fuel_type','0') IN ('$fuel_type1', '$fuel_type2', '$fuel_type3', '$fuel_type4’)";
didn't worked :((
any help will be appreciated.
答
problem is in your concatenation process
in PHP there should b a do t. to concatenate not + sign
if($fuel_type1 != 0)
{
$sql .= “ AND fuel_type IN ('$fuel_type1', '$fuel_type2', '$fuel_type3', '$fuel_type4')”;
}