MySQL JOIN 一个表或其他表

Question

上下文：
数据库是关于手机的。我在TABLE sav("售后服务"记录)中有一个搜索引擎，该搜索引擎有一个包含手机IMEI(其唯一ID)的字段phone。
在某些情况下，手机将重新存放在我们的库存中(从TABLE sales中删除并插入TABLE stock)，另一部手机将退还给客户。

问题：
在"售后服务"的搜索引擎中，我曾经LEFT JOIN sales，但万一手机在stock中回去了，它的IMEI将无法找到它。

总而言之：

如果找到记录，我需要连接一个表，否则，连接另一个表。

我的实际查询：
我缩短了它([...])以使其可读：

SELECT sav.id, sav.phone, [...] FROM sav 
LEFT JOIN sales ON (sav.phone = sales.imei)
LEFT JOIN stock_model ON (sales.model = stock_model.id) [...]
WHERE (sales.imei LIKE :search_1 OR [...])
OR (sales.imei LIKE :search_2 OR [...])
OR [...]

我需要更改第二行，但我不明白如何更改。我之前读过的问题似乎回答了具体的情况。

编辑：表结构和虚拟数据
我不会发布不相关的字段(太多)
TABLEsav

| id | phone     | issue   | replacement_imei | ...
----------------------------------------------------
| 35 | 123456789 | battery | NULL             | ...     <-- phone n°1
| 54 | 987654321 | screen  | 147258369        | ...     <-- phone n°2 replaced by phone n°3

TABLEstock

| id  | imei      | model | color | memory | ...
-------------------------------------------------
| 68  | 369258147 | 2     | 4     | 1      | ...
| 92  | 987654321 | 5     | 8     | 3      | ...     <-- phone n°2 replaced by phone n°3

TABLEsales

| id  | imei      | model | color | memory | ...
-------------------------------------------------
| 68  | 123456789 | 2     | 4     | 1      | ...     <-- phone n°1
| 103 | 147258369 | 5     | 8     | 3      | ...     <-- phone n°3 replaced phone n°2

编辑：完整的搜索引擎[PHP]：如果整个功能有帮助：

$keywords = explode(" ", $keywords);
$query = "SELECT sav.id, sav.phone, sav.date, sav.nom, sav.issue, sav.replacement_imei, sav.commentaire, sav.attente, sav.pieces, sav.frais, sav.date_envoi, sav.tracking, sav.termine FROM sav LEFT JOIN sales ON (sav.phone = sales.imei) LEFT JOIN stock_memory ON (sales.memory = stock_memory.id) LEFT JOIN stock_color ON (sales.color = stock_color.id) LEFT JOIN stock_model ON (sales.model = stock_model.id) LEFT JOIN stock_grade ON (sales.grade = stock_grade.id) WHERE ";
// Makes a long query returning each row where at least 1 keyword matches 1 column
$query_array = array();
for ($i = 0; $i < count($keywords); $i += 1) {
$query .= " ( sales.imei LIKE :search_" . $i;
$query .= " OR ( sales.snowden = 1 AND 'snowden'= :search_" . $i . " )";
$query .= " OR stock_model.name LIKE :search_" . $i;
$query .= " OR stock_color.name LIKE :search_" . $i;
$query .= " OR stock_memory.amount LIKE :search_" . $i;
$query .= " OR stock_grade.name LIKE :search_" . $i;
$query .= " OR sav.id LIKE :search_" . $i;
$query .= " OR DATE_FORMAT(sav.date, '%d/%m/%Y') LIKE :search_" . $i;
$query .= " OR sav.nom LIKE :search_" . $i;
$query .= " OR sav.issue LIKE :search_" . $i;
$query .= " OR sav.replacement_imei LIKE :search_" . $i;
$query .= " OR sav.commentaire LIKE :search_" . $i;
$query .= " OR sav.attente LIKE :search_" . $i;
$query .= " OR sav.pieces LIKE :search_" . $i;
$query .= " OR sav.frais LIKE :search_" . $i;
$query .= " OR DATE_FORMAT(sav.date_envoi, '%d/%m/%Y') LIKE :search_" . $i;
$query .= " OR sav.tracking LIKE :search_" . $i;
$query .= " OR ( sav.termine = 1 AND 'termine'= :search_" . $i . " )";
// $query .= "LIKE :search_" . $i;
if ($i != (count($keywords) - 1)) {
$query .= " ) AND ";
} else {
$query .= " ) ";
}
if (strtolower($keywords[$i]) == 'snowden' || strtolower($keywords[$i]) == 'termine') {
$query_array['search_' . $i] = $keywords[$i];
} else {
$query_array['search_' . $i] = "%" . $keywords[$i] . "%";
}
}
$query .= "ORDER BY sav.id DESC LIMIT $offset, $limit";
$results = $this->bdd->prepare($query);
$results->execute($query_array);
return $results;

Answer 1

首先，我获取具有完整外部连接的所有数据，然后 Sales.Model => 从Stock_Model中选择所有 ID。

SELECT sav.id, sav.phone, [...] FROM sav 
FULL OUTER JOIN sales ON (sav.phone = sales.imei)
WHERE sav.phone = sales.imei or sales.model in (select Id from stock_model)