NATURAL JOIN

语法说明

NATURAL JOIN 相当于 INNER JOIN，作用是将两个表中具有相同名称的列进行匹配。

语法结构

1. > SELECT table_column1, table_column2...
2. FROM table_name1
3. NATURAL JOIN table_name2;

示例

1. create table t1(id int,desc1 varchar(50),desc2 varchar(50));
2. create table t2(id int,desc3 varchar(50),desc4 varchar(50));
3. INSERT INTO t1(id,desc1,desc2) VALUES(100,'desc11','desc12'),(101,'desc21','desc22'),(102,'desc31','desc32');
4. INSERT INTO t2(id,desc3,desc4) VALUES(101,'desc41','desc42'),(103,'desc51','desc52'),(105,'desc61','desc62');

6. mysql> SELECT t1.id,t2.id,desc1,desc2,desc3,desc4 FROM t1 NATURAL JOIN t2;
7. +------+------+--------+--------+--------+--------+
8. | id   | id   | desc1  | desc2  | desc3  | desc4  |
9. +------+------+--------+--------+--------+--------+
10. |  101 |  101 | desc21 | desc22 | desc41 | desc42 |
11. +------+------+--------+--------+--------+--------+
12. 1 row in set (0.00 sec)