Question

如何用SQL SERVER取分组数据第一条

Answer 1

根据table1_id进行分组所得结果：

select * from (select a.id as a_id,a.name,a.time,a.content,b.id as b_id,b.user from table1 a inner join table2 b on a.id = b.table1_ID) new_tbl where b_id in (select min(id) from table2 group by table1_ID)

扩展资料：

注意事项

在SQL Server数据库中，使用top关键字：SELECT TOP number|percent column_name(s) FROM table_name

在MySQL数据库中，使用LIMIT关键字：SELECT column_name(s) FROM table_name LIMIT number

例子:SELECT * FROM Persons LIMIT 1 

select   bookName   from   book   where   price   >   20   limit   1; 

limit   1;
or
limit   0,1;

在Oracle数据库中，使用ROWNUM关键字：

SELECT column_name(s) FROM table_name WHERE ROWNUM <= number

例子:SELECT * FROM Persons WHERE ROWNUM <= 1