sql server中,返回影响行数是:If @@RowCount<1 Oracle中,返回影响行数是:If sql%rowcount<1 例: sqlserver: create procedure Proc_test , )='', AS BEGIN Update T_Mt Set Stat=@Stat,OStat=@Stat,RptTime=Getdate() Where MsgId=@MsgId --没有更新成功就插入到t_Statbuf insert into t_statbuf(M
创建表和输入数据 CREATE TABLE STUDENT(SNO VARCHAR(3) NOT NULL, SNAME VARCHAR(4) NOT NULL, SSEX VARCHAR(2) NOT NULL, SBIRTHDAY DATETIME, CLASS VARCHAR(5))goCREATE TABLE COURSE(CNO VARCHAR(5) NOT NULL, CNAME VARCHAR(10) NOT NULL, TNO VARCHAR(10) NO
select 1 是比select *更有效率的写法 因为它不返回具体的数据记录,而是返回n行的1 select 1 from studentsselect class,count(1) as pax from students group by class 作用:可以用来查询表中是否有符合条件的记录(比如select 1 from seckill where id = 1001;), select 1一般用来当作条件使用,比如exists( select 1 from 表名)等.select
select Category,REPLACE(sum(Amount),'-','') as Amountfrom T_Detail WHERE CREATED_BY='6123EC14-50E2-4D4A-AACA-6A9578AAFDBB'group by Category 说明:Amount中的减号为支出标记,统计时去掉
select Category from(select distinct Category from T_Detail where CREATED_BY= @CREATED_BY AND RecordDate>=@RecordDate1 AND RecordDate<@RecordDate2)t group by Category 说明: CREATED_BY 为创建人ID RecordDate为创建日期
select 1 from table 语句中的1代表什么意思 在这里我主要讨论的有以下几个select 语句: doo_archive表是一个数据表,表的行数为4行,如下: 分别用三条select语句select 1 from doo_archive.select count(1) from doo_archive.select sum(1) from doo_archive进行测试,发现结果如下: 1:测试结果,得出一个行数和doo_archive表行数一样的临时列,每行的列值是1,
SqlParameter[] param = { new SqlParameter("@shopId",shopId), new SqlParameter("@newShopStr",newShopStr), new SqlParameter("@userId",userId), ), ) }; 注意:output参数需要定义大小,否则只能获取到一个字符
一.SQL子查询语句 1.单行子查询 select ename,deptno,sal from emp where deptno=(select deptno from dept where loc='NEW YORK'): 2.多行子查询 SELECT ename,job,sal FROM EMP WHERE deptno in ( SELECT deptno FROM dept WHERE dnam