Nested “ifs” in a select-where for a conditional dynamic filtering

问题

Recently I created a new website based on codeigniter 3-php and PHPMyADMIN-mysql and I integate one pagination more than that i did a dynamic search with ajax. My problem is when I have more than 1 million 500 thousand results the query starts to put a lot of time.

And for this solution I considered using triggers. So I have a little trouble when I use triggers is when I try to make a dynamic filter, I make an example to better understand,I want to know the number of rows corresponding to a filter stored in another dynamic table.

BEGIN
UPDATE max_tare
SET max_row = (SELECT COUNT(*)FROM history 
IF(new.client != '') THEN
WHERE nom LIKE CONCAT('%', NEW.client, '%') END IF;
IF(new.commune != '') THEN
WHERE commune LIKE CONCAT('%', NEW.commune, '%') END IF;
IF(new.type != '') THEN
WHERE type LIKE CONCAT('%', NEW.type, '%') END IF;
IF(new.matricule != '') THEN
WHERE mat LIKE CONCAT('%', NEW.matricule, '%') END IF;
IF(new.tare != '') THEN
WHERE tare LIKE CONCAT('%', NEW.tare, '%') END IF;
WHERE cancled = 0), 
    max_tare =(SELECT SUM(tare) FROM history
     WHERE cancled = 0) WHERE id = 1;
END

The problem is if I delete all the ifs statement conditions, my filter will not work, if my filter contain an empty field, it broke the result to 0, I want if its an empty field its doesn't count as a parameter of the filtering. I have tried also case statements this also doesn't help.

When I run the code this is what I get like error:

MySQL replied: # 1064 - Syntax error near 'IF' (new.client! = '') THEN WHERE name LIKE CONCAT ('%', NEW.client, '%') END IF;

There is somehow a long way solution that work but I don't need because I can't call it as a solution:
It is to take out the outside, and make a select from for each case obtained, in other words:

if (client! = 0 and common == 0 and type == 0 and number == 0 and tare == 0) then
{filter by client only}
otherwise-if (client! = 0 and common! = 0 and type == 0 and number == 0 and tare == 0) then
{filter by client and common only} .... ect

I will try to make an example to make it more clear: This is my history table:

|                                         history                                |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| id | nom         | commune | type   | mat          | tare  | rfid    | cancled |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 1  | EPIC paris  | france  | white  | 01248-816-16 | 7600  | ABCF44C | 0       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 2  | EPIC london | UK      | white  | 06854-315-16 | 5233  | A8CG27C | 1       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 3  | NET barça   | ESP     | red    | 03254-615-16 | 8900  | HBC54AC | 1       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 4  | NET Dubai   | arab    | blue   | 35251-117-16 | 11200 | HDK7BV5 | 0       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 5  | EPIC roma   | ita     | red    | 36524-618-16 | 7300  | NBL53DC | 0       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 6  | SNC beta    | alpha   | green  | 69358-117-16 | 5400  | JDLF8ND | 1       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 7  | EPIC tokyo  | japan   | yellow | 46258-712-16 | 8700  | K5ND55D | 1       |
+----+-------------+---------+--------+--------------+-------+---------+---------+
| 8  | SARL Fit    | body    | black  | 69531-614-16 | 9600  | AIES5HJ | 0       |
+----+-------------+---------+--------+--------------+-------+---------+---------+

I want to retrieve the number of rows that contain cancled = 0 and in their name they have EPIC

So my filer array will be like this :

|                     temp_fetch                     |
+----+--------+---------+------+--------------+------+
| id | client | commune | type | matricule    | tare |
+----+--------+---------+------+--------------+------+
| 1  | EPIC   |         |      |              |      |
+----+--------+---------+------+--------------+------+

As a result I should have something like this

|          max_tare          |
+----------------------------+
| id |  max_row   | max_tare |
+----+------------+----------+
| 1  |     2      | 14900    |
+----+------------+----------+

If its help i will put there my php code that work but take too much to load the results


$this->db->from('history');

if ($query[1] != '') {
    $this->db->like('nom', $query[1]);
                }
if ($query[2] != '') {
    $this->db->like('commune', $query[2]);
                }
if ($query[3] != '') {
    $this->db->like('type', $query[3]);
                }
if ($query[4] != '') {
    $this->db->like('mat', $query[4]);
                }
if ($query[10] != '') {
    $this->db->like('rfid', $query[10]);
                }
if ($query[5] != '') {
    $this->db->like('tare', $query[5]);
                }
if ($query[6] != '') {
    $this->db->where('date >', $query[6]);
                }
if ($query[7] != '') {
    $this->db->where('date <', $query[7]);
                }
if ($query[11] != '') {
    $this->db->where('time_plode >', $query[11]);
                }
if ($query[12] != '') {
    $this->db->where('time_plode <', $query[12]);
                }
$this->db->where('cancled', 0);
return $this->db->count_all_results();

回答1:

Are you looking for a join and group by?

select f.id,
       count(*) as num_rows,
       sum(tare) as sum_tare
from history h join
     temp_fetch f
     on h.nom like concat('%', f.client, '%') or
        h.commune like concat('%', f.commune, '%')  or 
        h.type like concat('%', f.type, '%') or 
        h.mat like concat('%', f.matricule, '%') or 
        h.tare like concat('%', f.tare, '%')
where f.cancled = 0
group by f.id;

来源：https://stackoverflow.com/questions/56290552/nested-ifs-in-a-select-where-for-a-conditional-dynamic-filtering

标签

mysql

sql

triggers

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