Sometimes there is a need to loop through records and process a record at a time in a Transact-SQL script or stored procedure in Microsoft SQL Server. It may not be the most efficient approach, but it may be the only option. In this tutorial, we look at how to create a WHILE loop ...
5 rows in set (0.00 sec) 一行就是执行结果,实际的作用和使用while编写的存储过程一样,都是插入5行数据。 再来看一下第三个循环控制语句LOOP……END LOOP。编写一个存储过程程序如下: mysql> create procedure pro12() -> begin -> declare i int default 0; -> loop_label: loop -> insert into t1(...
BEGIN OPEN c_num3; FETCH c_num3 INTO v_num3; WHILE c_num3%FOUND LOOP -- 能找到数据则执行循环内语句 FETCH c_num3 INTO v_num3; END LOOP; CLOSE c_num3; END; -- for DECLARE v_num2 VARCHAR2(100); CURSOR c_num2 IS SELECT NAME FROM test_t WHERE ROWNUM < 600000; BEGIN dbms_...
C.PROJECTID AND C.YEAR_DATE = D.TIME) T ORDER BY ID,PROJECTNAME,TIME )C ON A.ID = C.ID AND B.TIME = C.TIME ORDER BY a.ID,b.TIME'; TARGET_RESULTS := TARGET_RESULTS || ') ' || ALIAS || ' '; --循环拼接关联SQL FOR TEMP IN DATA LOOP --给待拼接的字段赋值 STR := ...
mysql while,loop,repeat循环,符合条件跳出循环 1、while循环 DELIMITER $$DROPPROCEDUREIFEXISTS`sp_test_while`$$CREATEPROCEDURE`sp_test_while`(INp_numberINT, #要循环的次数INp_startidINT#循环的其实值 )BEGINDECLAREv_valINTDEFAULT0;SETv_val=p_startid;...
TARGET_RESULTS :=TARGET_RESULTS||'ON B.ID = C.PROJECTID AND C.YEAR_DATE = D.TIME) T ORDER BY ID,PROJECTNAME,TIME )C ON A.ID = C.ID AND B.TIME = C.TIME ORDER BY a.ID,b.TIME'; TARGET_RESULTS :=TARGET_RESULTS||') '||ALIAS||' ';--循环拼接关联SQLFORTEMPINDATA LOOP--给...
PostgreSQL是一个开源的关系型数据库管理系统,提供了丰富的函数和扩展功能。其中,while/loop函数是一种循环函数,用于在数据库中执行重复的操作。 循环函数是一种控制结构,允许在满足特定条件的情况下重复执行一段代码。在PostgreSQL中,while/loop函数可以使用PL/pgSQL编写,是一种过程化语言,用于编写存储过程、触发器和...
LOOP -基本循环 WHILE -根据条件循环 FOR -固定次数的循环 create table T_TEST ( id number(5), num number(10) ); 1. 2. 3. 4. 5. LOOP 语法 LOOP sequence_of_statements END LOOP; 1. 2. 3. 4. 5. 示例 DECLARE v_count NUMBER(5):=1; ...
MySQL provides loop statements that allow you to execute a block of SQL code repeatedly based on a condition. There are three loop statements in MySQL:WHILE,REPEATandLOOP. We will examine each statement in more detail in the following section. ...
MySQL存储过程的参数用在存储过程的定义,共有三种参数类型,IN,OUT,INOUT,形式如: CREATE PROCEDURE([[IN |OUT |INOUT ] 参数名 数据类形...]) IN 输入参数:表示该参数的值必须在调用存储过程时指定,在存储过程中修改该参数的值不能被返回,为默认值 ...