--测试数据
CREATE TABLE ta(id int)
INSERT ta SELECT 1
CREATE TABLE tb(id int)
INSERT tb SELECT 1
UNION ALL SELECT 1
CREATE TABLE tc(id int)
INSERT tc SELECT 1
UNION ALL SELECT 1
--查询
SELECT *
FROM ta a
JOIN tb b ON a.id=b.id
JOIN tc c ON a.id=c.id
/*--结果
id id id
----------- ----------- -----------
1 1 1
1 1 1
1 1 1
1 1 1
--*/
CREATE TABLE ta(id int)
INSERT ta SELECT 1
CREATE TABLE tb(id int)
INSERT tb SELECT 1
UNION ALL SELECT 1
CREATE TABLE tc(id int)
INSERT tc SELECT 1
UNION ALL SELECT 1
--查询
SELECT *
FROM ta a
JOIN tb b ON a.id=b.id
JOIN tc c ON a.id=c.id
/*--结果
id id id
----------- ----------- -----------
1 1 1
1 1 1
1 1 1
1 1 1
--*/