将数据库表中的分组值与关联数组进行比较

Question

I have three PHP arrays which all have the same two keys: pId and name . The name of the arrays are added , deleted & updated .

The table I want to compare with looks like this:

id
relationId
pId
name
changeType

The rows are grouped by the relationId and there may be multiple pId & name pairs per relationId. changeType can be either added , deleted or updated .

What I want is to be able to run a single query that checks if a group of pId & name pairs (where the changeType matches the array name) that matches the three arrays exactly, exists in the table and return the relationId .

Is this possible?

---

Example

Table:

+--------+----------------+---------+---------------+----------------+
| **id** | **relationId** | **pId** |    **name**   | **changeType** |
+--------+----------------+---------+---------------+----------------+
|    1   |        1       |    1    |     Smith     |      added     |
+--------+----------------+---------+---------------+----------------+
|    2   |        1       |    2    |      John     |     updated    |
+--------+----------------+---------+---------------+----------------+
|    3   |        1       |    3    |     Dexter    |     deleted    |
+--------+----------------+---------+---------------+----------------+
|    4   |        1       |    4    |   Heisenberg  |      added     |
+--------+----------------+---------+---------------+----------------+
|    5   |        2       |    4    |   Heisenberg  |      added     |
+--------+----------------+---------+---------------+----------------+
|    6   |        2       |    3    |     Dexter    |     updated    |
+--------+----------------+---------+---------------+----------------+
|    7   |        2       |    3    | Dexter Morgan |     updated    |
+--------+----------------+---------+---------------+----------------+

PHP Array:

$added = array(
 [1] = array(
    pId => 4,
    name => 'Heisenberg'
 ) 
)

$deleted = array(
 //Empty
)

$updated = array(
 [1] = array(
    pId => 3,
    name => 'Dexter'
 )
 [2] = array(
    pId => 3,
    name => 'Dexter Morgan'
 ) 
)

When querying using this array the returned relationId should be 2.

Answer 1

I solved this by comparing an imploded string from the arrays with GROUP_CONCAT on the table. Since you can't normally use GROUP_CONCAT in the WHERE clause I had to do a workaround with the FROM clause.

<?php
    $s = '';
    foreach($updated as $u){
        $s .= $u['pId'] . $u['name'] . 'updated,';
    }
    foreach($deleted as $d){
        $s .= $d['pId'] . $d['name'] . 'deleted,';
    }
    foreach($added as $a){
        $s .= $a['pId'] . $a['name'] . 'added,';
    }

    //remove last comma
    $s = rtrim($s, ',');

    $stmt = $mysqli -> prepare("
    SELECT 
        relationId
        FROM (
            SELECT
                relationId, 
                GROUP_CONCAT(pId, name, changeType ORDER BY changeType DESC, id ASC) AS personConcat
            FROM 
                persons
            GROUP BY relationId
        ) x
        WHERE personConcat = ?
    ");

    $stmt -> bind_param('s', $s);
    $stmt -> execute();
?>