最近在加强sql 语句的学习,整理一下基本语法,现在记录下 select * from dbo.cangku where city='河南' select distinct(city), cangkuId from dbo.cangku //取消重复的列值 select SUM (gongzi) as zgz from dbo.zhigong //总工资 select cangkuId ,city from dbo.cangku where not city='河南'…
基本常用查询 --select select * from student; --all 查询所有 select all sex from student; --distinct 过滤重复 select distinct sex from student; --count 统计 select count(*) from student; select count(sex) from student; select count(distinct sex) from student; --top 取…
-- Get childs by parent id WITH Tree AS ( SELECT Id,ParentId FROM dbo.Node P WHERE P.Id = -- parent id UNION ALL SELECT C.Id,C.ParentId FROM dbo.Node C INNER JOIN Tree T ON C.ParentId = T.Id ) SELECT * FROM Tree -- Get parents by child id WITH Tree A…
-- 根据父ID得到所有子ID -- Get childs by parent idWITH TreeAS( SELECT Id,ParentId FROM dbo.Node P WHERE P.Id = 21 -- parent id,即父记录 UNION ALL SELECT C.Id,C.ParentId FROM dbo.Node C INNER JOIN Tree T ON C.ParentId = T.Id -- 所有子记录) SE…
这个也有用: -- Get childs by parent idWITH TreeAS( SELECT Id,ParentId FROM dbo.Node P WHERE P.Id = 21 -- parent id UNION ALL SELECT C.Id,C.ParentId FROM dbo.Node C INNER JOIN Tree T ON C.ParentId = T.Id)SELECT * FROM Tree -- Get parents by child idWITH Tr…
SQL Server T-SQL高级查询 高级查询在数据库中用得是最频繁的,也是应用最广泛的. Ø 基本常用查询 --select select * from student; //查询student表中所有字段. --all 查询所有 select all sex from student; --distinct 过滤重复 select distinct sex from student; --count 统计 select count(*) from student; selec…