MySQL 有一个表，表里边有只一个 name 字段，表里面只有name是 a、b、c、d 的四条数据，怎么用一个 SQL 查询它们的所有排列组合

SELECT 
    t1.name AS name1, 
    t2.name AS name2, 
    t3.name AS name3, 
    t4.name AS name4
FROM 
    team t1
    JOIN team t2 ON t1.name <> t2.name
    JOIN team t3 ON t1.name <> t3.name AND t2.name <> t3.name
    JOIN team t4 ON t1.name <> t4.name AND t2.name <> t4.name AND t3.name <> t4.name;

结果