Could not check value within two column using MySQL query

Question

I am facing one issue. I need to check value which should present within two column values using PHP and MySQL. I am explaining my table below.

id      zip_from               zip_to

     1        751001                751030

db_postcode:

$post_code='751010';
$sql="select * from db_postcode where zip_from >='".$post_code."' and zip_to='".$post_code."'";
$sqlpin=mysqli_query($conn,$sql);
if (mysqli_num_rows($sqlpin) > 0) {
    $data=array("status"=>"Success","msg"=>"Product is available for this postcode");
}else{
    $data=array("status"=>"Failed","msg"=>"Product is not available for this postcode");
}
echo json_encode($data);

Here I am getting the message {"status":"Failed","msg":"Product is not available for this postcode"} which is wrong because code 751010 is present within 751001-751030 . Here I need to check the user given value should be present within that two column.

Answer 1

Your compare is written the wrong way around, what you want is to check that $post_code is between zip_from and zip_to :

$sql="select * from db_postcode where '$post_code' between zip_from and zip_to";

Note that this will only work if all zip_from , zip_to and $post_code values are the same length, otherwise you will run into issues that in a string compare, 2 > 100000 . If they are not the same length, you should cast them to integer to compare them.

Answer 2

好吧，您的查询应该是这样的：

$sql="select * from db_postcode where ".$post_code." BETWEEN zip_from and zip_to";