摘要： --1. 创建表，添加测试数据CREATE TABLE tb(id int, [value] varchar(10))INSERT tb SELECT 1, 'aa'union ALL SELECT 1, 'bb'union ALL SELECT 2, 'aaa'union ALL SELECT 2, 'bbb'union ALL SELECT 2, 'ccc'--SELECT * FROM tb/**//*id value----------- ----------1 aa1 bb2 aaa2 bbb2 ccc( 阅读全文