Question

我有3个不同的表，基于第一个表中的搜索，我能够从第二个获取数据，并且根据第一个和第二个搜索，我能够从第3个表中获取数据。

表格如下：

table cases
+-------+----------+------------+---------+
|case_id| car_model|     vin    | country |
+-------+----------+------------+---------+
|  1    |    VW    |   ABCDEFG  |    EN   |
+-------+----------+------------+---------+
|  2    |    VW    |   GFEDCBA  |    PL   |
+-------+----------+------------+---------+
table calculations
+-------+---------------+------------+---------+
|case_id|calculation_id |    price   | country |
+-------+---------------+------------+---------+
|   1   |45545662512    |    11000   |    EN   |
+-------+---------------+------------+---------+
|   1   |45545662512    |     7000   |    PL   |
+-------+---------------+------------+---------+
|   2   |1234561234     |     3000   |    EN   |
+-------+---------------+------------+---------+
|   2   |3214561234     |     6000   |    EN   |
+-------+---------------+------------+---------+
table positions
+-------+------------+------------+--------------+
|case_id|repairmethod|    text    |calculation_id|
+-------+------------+------------+--------------+
|   1   |     L      |    hallo   |  7894561234  |
+-------+------------+------------+--------------+
|   1   |     L      |     hi1    |  45545662512 |
+-------+------------+------------+--------------+
|   2   |     L      |     hi2    |  45545662512 |
+-------+------------+------------+--------------+
|   2   |     E      |     hi3    |  45545662512 |
+-------+------------+------------+--------------+
|   2   |     G      |     hi4    |  45545662512 |
+-------+------------+------------+--------------+
|   2   |     L      |     hi5    |  3214561234  |
+-------+------------+------------+--------------+
|   2   |     L      |     hi6    |  3214561234  |
+-------+------------+------------+--------------+

我是怎么写的：

从表号1获取数据和case_id：

“SELECT * FROM case WHERE vin =：vin ORDER BY date_created DESC LIMIT 60”;
基于case_id，我从表2中的第一个表搜索中获取，取最后一行：

“SELECT * FROM computation WHERE case_id =：case AND country =：country ORDER BY calculation_id DESC LIMIT 1”;
根据表1中的case_id和表2中的calculation_id在表3中搜索：

“SELECT text FROM positions WHERE calculation_id =：calculationid AND case_id =：case_id AND repairmethod LIKE'L％'LIMIT 60”;

如果用户搜索ABCDEFG，则预期结果为：

来自表格案例：

car_model = VW
country = EN
case_id = 1

从表格计算：

calculation_id = 45545662512    
price = 11 000

从表位：

text = hi1
text = hi2

但是这个查询基于PHP，在变量值中存储值等等，是否有机会在一个SELECT中写下我之前的所有语句？

我已尝试使用INNER JOIN

"SELECT * FROM cases v INNER JOIN calculations c
                    ON v.case_id = c.case_id
                    INNER JOIN positions p
                    ON v.case_id = p.case_id
                    WHERE v.vin = :vin
                    ORDER BY c.name DESC
                    LIMIT 4";

但是有多个问题，有限制，选择多个WHERE，依此类推。我想念一下吗？

感谢您的帮助。

Answer 1

试试这个：

SELECT cases.case_id, cases.car_model, cases.country, 
       calculations.calculation_id, calculations.price, 
       positions.text 
FROM cases INNER JOIN
calculations ON(cases.case_id = calculations.case_id AND cases.country = calculations.country) INNER JOIN
positions ON(calculations.case_id = positions .case_id AND calculations.calculation_id = positions.calculation_id)
WHERE vin = :vin

注意：如果您搜索＆＃39; ABCDEFG＆＃39;，这将为您提供2行数据，每个记录位置表中有一行。

如何从一个SELECT [MySQL]中的3个表中获取数据

1 个答案: