While SQL While loop is quicker than a cursor, reason found that cursor is defined by DECLARE CURSOR. Every emphasis of the loop will be executed inside system memory and consuming required server assets. On the off chance that the iteration count is extremely high, at...
Creating a SQL Server cursor with T-SQL is a consistent method that can process data on a set of rows. Once you learn the steps, you can easily duplicate them with various sets of logic to loop through data. Let’s walk through the steps: Declare Variables Declare the variables (file n...
The numericFOR LOOPexecutes the body of a loop once for every integer value in a specified range. Similarly, the cursorFOR LOOPexecutes the body of the loop once for each row returned by thequeryassociated with the cursor. A nice feature of the cursorFOR LOOPstatement is that it allows you...
5、open cursor后要注意close cursor declare--存储域名type t_curisrefcursor; domainNames t_cur; domainNamevarchar2(50) :='';--存储每个域下的网元类型cursormoTypeNames(domainVARCHAR2)ISselectt1.modelnamefrompm4h_mo.mdl_resmodel t1,pm4h_mo.mdl_domain t2wheret2.domainname=domainandt1.domainid=...
跳转语句之ITERATE语句 ITERATE语句:只能用在循环语句(LOOP、REPEAT和WHILE语句)内,表示重新开始循环,将执行顺序转到语句段开头处。如果你有面向过程的编程语言的使用经验,你可以把 ITERATE 理解为 continue,意思为 再次循环。 语句基本格式如下: ITERATE label...
This Oracle tutorial explains how to use the CURSOR FOR LOOP in Oracle with syntax and examples. The syntax for the CURSOR FOR Loop in Oracle / PLSQL is:
游标Cursor逻辑运算符和物理运算符用于描述涉及游标操作的查询或更新的执行方式。 其中物理运算符描述用于处理游标(如使用键集驱动游标)的物理实现算法。 游标执行过程的每一步都涉及物理运算符。 而逻辑运算符描述游标的属性,如游标是只读。 逻辑运算符包括Asynchronous、Optimistic、Primary、Read Only、Scroll Locks、Seco...
Create Sample Tables and Data First, let’s create some sample tables and data for the cursor examples. CREATE TABLE [dbo].[Employees]( [Id] [int] NULL, [Firstname] [varchar](50) NULL, [Lastname] [varchar](50) NULL, [Phone] [varchar](50) NULL, ...
B. Use WHILE in a cursor The following example uses@@FETCH_STATUSto control cursor activities in aWHILEloop. SQL DECLARE@EmployeeIDASNVARCHAR(256)DECLARE@TitleASNVARCHAR(50)DECLAREEmployee_CursorCURSORFORSELECTLoginID, JobTitleFROMAdventureWorks2022.HumanResources.EmployeeWHEREJobTitle ='Marketing Speciali...
You are fetching the next record outside the WHILE loop using the above code. So the @@FETCH_STATUS is always 0 and the loop is executed infinitely. Place the above statement inside the WHILE loop. For more details refer below article....