从所有表中具有相同主键的多个表中获取数据

I have 4 tables all with the same primary key with structure like :

我有4个表，主键相同，结构类似:

table_1 : u_id | col1 | col2    

table_2 : u_id | col3 | col4     

table_3 : u_id | col5 | col6    

table_4 : u_id | col7 |  col8

I want to fetch the data of "col1", "col4", "col6" and "col7" on the basis of the value of u_id.

我想在u_id值的基础上获取“col1”、“col4”、“col6”和“col7”的数据。

Values of u_id are same in every table.

u_id的值在每个表中都是相同的。

For eg. if u_id='8', then fetch all the specified column values where u_id='8'.

如。如果u_id='8'，则获取u_id='8'的所有指定列值。

I am not using joins correctly, i guess.

我猜我没有正确地使用连接。

Thanks.

谢谢。

2 个解决方案

#1

This should be pretty straight forward. Use INNER JOIN

这应该是非常直接的。使用内连接

SELECT  a.col1, b.col4, c.col6, d.col7
FROM    table1 a
        INNER JOIN table2 b
            ON a.u_id = b.uid
        INNER JOIN table3 c
            ON a.u_id = c.uid
        INNER JOIN table4 d
            ON a.u_id = d.uid
WHERE   a.u_ID = 8

To learn more about joins, please see the article below.

要了解有关连接的更多信息，请参阅下面的文章。

Visual Representation of SQL Joins
SQL连接的可视化表示

#2

SELECT 
table_1.col1, 
table_2.col4, 
table_3.col6, 
table_4.col7 
FROM
table_1,
table_2,
table_3,
table_4
WHERE
table_1.u_id = '8' AND
table_1.u_id = table_2.u_id AND
table_1.u_id = table_3.u_id AND
table_1.u_id = table_4.u_id

#1