游标可以分为隐式游标和显式游标。隐式游标是PL/SQL自动管理的,主要用于处理SQL语句的执行结果。显式游标则需要我们手动声明、打开、获取数据和关闭。 二、游标的使用方法 声明游标 在PL/SQL中,我们需要使用DECLARE语句来声明游标。例如,以下代码声明了一个名为my_cursor的游标,用于查询dept表中的dname字段: DECLARE CURSOR
The values retrieved from a table are held in a cursor opened in memory by the oracle engine. This data is then transferred to the client machine via the network.in order to hold this data; a cursor is opened at the client end. If the numbers of rows returned by the oracle engine is...
就返回FALSE declare cursor cur_users is select * from ma_users; begin --如果没有打开游标就使用这个属性,就会报invalid_cursor异常 /* if cur_users%found then dbms_output.put_line('更新积分'); end if; */ for v in cur_users loop update ma_users t set t.user_point = 1000 where t.id...
24FORIDX1IN1.. EMPS.COUNTLOOP 25DBMS_OUTPUT.PUT_LINE('empno:'||EMPS(IDX1).EMPNO); 26END
光标:oracle学习PL/SQL基础之光标cursor使用 本文将介绍光标语法、光标属性之一。然后怎么使用光标。然后来个小实例。 光标 语法: Cursor 光标名[(参数名 数据类型[,参数2数据类型2]...)] IS select 语句; 使用步骤: 1.定义光标:cursor Cursor c1 is select ename from emp;...
PLSQL带参数的CURSOR 开始 SETSERVEROUTPUTON;DECLAREv_empno emp.empno%TYPE; v_ename emp.ename%TYPE;CURSORemp_cursor (p_deptnoNUMBER,p_jobVARCHAR2)ISSELECTempno,enameFROMempWHEREdeptno=p_deptnoANDJOB=p_job; emp_record emp_cursor%ROWTYPE;BEGINLOOPIFNOTemp_cursor%ISOPENTHENOPENemp_cursor(30,'...
12.PL_SQL——游标CURSOR SQL> edit DECLARE CURSORc_emp_cursor IS SELECTemployee_id, last_name FROMemployees WHEREdepartment_id = 30; v_empnoemployees.employee_id%TYPE; v_lnameemployees.last_name%TYPE; BEGIN OPEN c_emp_cursor; -- 1.打开游标...
This Oracle tutorial explains how to declare a cursor in Oracle / PLSQL with syntax and examples. A cursor is a SELECT statement that is defined within the declaration section of your PLSQL code.
INcursor Specifies the name of a previously declared cursor. LOOPandEND LOOP Starts and ends the loop containing SQL statements that are to be executed during each iteration through the loop. statements One or more PL/SQL statements. A minimum of one statement is required. ...
OPENcursor_name;Code language:PostgreSQL SQL dialect and PL/pgSQL(pgsql) In this syntax,cursor_nameis the name of the cursor you declare in the declaration section. When you open a cursor, Oracle parses the query, binds variables, and executes the associated SQL statement. ...