1.表结构test2(id,name)合并同ID的name字段,用逗号隔开。
2.测试表
3.不去重合并
SELECT ID ,GROUP_CONCAT(NAME SEPARATOR ',') NAMES FROM TEST2 GROUP BY ID;#不去重
4.去重合并
SELECT ID ,GROUP_CONCAT(DISTINCT NAME SEPARATOR ',') NAMES FROM TEST2 GROUP BY ID; #去重
SELECT ID ,GROUP_CONCAT(NAME SEPARATOR ',') NAMES FROM TEST2 GROUP BY ID;#不去重
SELECT ID ,GROUP_CONCAT(DISTINCT NAME SEPARATOR ',') NAMES FROM TEST2 GROUP BY ID; #去重