SQL合并列值和拆分列值
合并列值表结构,数据如下:需要得到结果:即:group by id, 求string的和(字符串相加)CREATE TABLE tb ( id INT, string VARCHAR(10));INSERT INTO tb VALUES ( 1, 'aa' );INSERT INTO tb VALUES ( 1, 'bb' );INSERT INTO tb VALUES ( 2, 'aaa' );INSERT INTO tb VALUES ( 2, 'bbb' );INSERT INTO tb VALUES ( 2, 'ccc' );SELECT * FROM dbo.tb;方法1SELEC