A cursor is a SELECT statement that is defined within the declaration section of your PLSQL code. We'll take a look at three different syntaxes for cursors. Cursor without parameters (simplest) The basic syntax for a cursor without parameters is: CURSOR cursor_name IS SELECT_statement; For ...
if the query returns no rows when the cursor is opened , PL/SQL does not raise an exception . However , you can test the status of the cursor after a fetch using the SQL%ROWCOUNT cursor attribute . fetch: FETCH cursor_name INTO [variable1, variable2 ...] | record_name ; 例如 : L...
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 my_cursor IS SELECT dname FROM dept; 打开游标 在声明游标后,我们需要使用OPEN语句来打开游标。例如: OPEN my_cursor; 获取数据 使用FETCH语句从游标中获取数据。FETCH语句...
Oracle also determines an execution plan, associates host variables andcursor parameterswith the placeholders in the SQL statement, determines the result set, and sets the cursor to the first row in the result set. More aboutparameterized cursorin the next tutorial. Fetch from a cursor# TheFETCHs...
emp_record emp_cursor%ROWTYPE; BEGIN LOOP IF NOT emp_cursor%ISOPEN THEN OPEN emp_cursor(30,'SALESMAN'); END IF; FETCH emp_cursor INTO emp_record; EXIT WHEN emp_cursor%NOTFOUND; dbms_output.put_line ('rowcount is:'|| emp_cursor%ROWCOUNT || '-- empno is:' || emp_record.empno ...
隐式cursor当然是相对于显式而言的,就是没有明确的cursor的declare。在Oracle的PL/SQL中,所有的DML操作都被Oracle内部解析为一个cursor名为SQL的隐式游标,只是对我们透明罢了。 另外,我们前面提到的一些循环操作中的指针for 循环,都是隐式cursor。 隐式cursor示例一: ...
隐式cursor当然是相对于显式而言的,就是没有明确的cursor的declare。在Oracle的PL/SQL中,所有的DML操作都被Oracle内部解析为一个cursor名为SQL的隐式游标,只是对我们透明罢了。 另外,我们前面提到的一些循环操作中的指针for 循环,都是隐式cursor。 隐式cursor示例一: ...
1、cursor传入参数 定义:cursor[cursor变量名称]([参数名称] [参数类型])IS[SQL语句,可以使用传入参数] 例子: cursormoTypeNames(domainVARCHAR2)IS selectt1.modelnamefrompm4h_mo.mdl_resmodel t1,pm4h_mo.mdl_domain t2 wheret2.domainname=domain ...
public interfacePlsqlCursorextendsPlsqlNode,PlsqlHasName,PlsqlHasFormals A plsql cursor declaration. Syntax is "CURSOR TYPE name ( formals ) RETURN return_type IS cursor_sql_stmt", where the TYPE keyword is optional, the formal part is optional, the RETURN part is optional, and ...
Parameters.Add("outRefPrm", OracleDbType.RefCursor, DBNull.Value, ParameterDirection.Output); cmd.ExecuteNonQuery(); // Execute the anonymous PL/SQL block // Reset the command object to execute another anonymous PL/SQL block cmd.Parameters.Clear(); cmd.CommandText = cmdTxt2; // REF Cursor ...