How to apply advance search query with multiple values and conditions - mysql

Question

I have a view where user select fields to make an advance search, the fields are:
**name**- **age** - **location** - **isPaid** - **date_subscription**, **date_expiration**
the user might choose one column or make combinations of multiple columns, I am confused if I should use if statement to detect which columns are selected, and then run the query depends on the selected column, but this way I will need to set all the valid conditions, which mean set the all the valid combination. Is there an other way to execute such queries?
I was writing this query, but i stopped because i just realize how long it will be:
SELECT * FROM internetclientdetails icd INNER JOIN internetclient ic on ic.id = icd.icid WHERE
(icd.date_sub <=".$start_dateSubsc." and cd.date_sub >= ".$end_dateSubsc.")
OR
(icd.date_exp <=".$start_dateExp." and cd.date_exp >= ".$end_dateExp.")
OR
(
(icd.date_sub <=".$start_dateSubsc." and cd.date_sub >= ".$end_dateSubsc.")
AND
(icd.date_exp <=".$start_dateExp." and cd.date_exp >= ".$end_dateExp.")
)
OR
.
.
.
but this is too long to be write since i still have 4 left fields to set OR , AND operators

Answer 1

Generally you add some already query building library, which can construct valid SQL from the input you select.
There are a number of them, for example, Doctrine DB abstraction layer, Medoo and a number of others.
For example, in Medoo a rather complex query such as:
SELECT account,user_name FROM table
WHERE user_id IN (2,123,234,54) OR
email IN ('foo#bar.com','cat#dog.com','admin#medoo.in')
will be writen in PHP as:
$database->select("account", "user_name", [
"OR" => [
"user_id" => [2, 123, 234, 54],
"email" => ["foo#bar.com", "cat#dog.com", "admin#medoo.in"]
]
]);
So all you have to do when using medoo is to pass it the correct input from the form.
As regards your question about how the user selects different columns, you can use something like this:
$mapping=array("start_dateSubsc"=>"date_sub", "end_dateSubsc"=>"date_sub",...);
where you list all the possible fields for user to enter in webpage, which are mapped to the real database table column names.
Then you do something like this, when you process the page:
$wherequery["OR"]=array();
foreach ($mapping as $userfield => $dbfield)
{
if array_key_exists($userfield, $_REQUEST)
array_push($wherequery["OR"], $dbfield => $_REQUEST[$userfield]);
}
$database->select("your columns"),[ $wherequery ]);
This will work for fields that need to be = to what user said and where you must match any of the fields.
You would have a bit more to do with fields that can be in range, and process them seperately, as well as processing fields with "AND", but that depends on the range and possibilities of your actual fields.