Sex cam no member ship - Cursor for updating table in sql oracle

DECLARE 2 CURSOR C1 IS SELECT EMP_CODE, EMP_SALARY FROM EMP; 3 BEGIN 4 FOR I IN C1 5 LOOP 6 UPDATE EMP_SAL 7 SET EMP_SALARY = I. EMP_CODE; 9 END LOOP; 10 END; 11 / PL/SQL procedure successfully completed.

cursor for updating table in sql oracle-82cursor for updating table in sql oracle-18

You are not required to make changes to the records in order to use this statement.

The record locks are released when the next commit or rollback statement is issued.

When the Fetch clause is used with a cursor having a FOR UPDATE clause, the PL/SQL unit fails when we try to open the cursor with an ORA-02014: cannot select FOR UPDATE from view with DISTINCT, GROUP BY, etc. The error description shows that the internal mechanism for the Fetch clause uses either a DISTINCT or a GROUP BY clause which is not permitted alongside the FOR UPDATE clause.

In this scenario, the cursor result set can be limited using the traditional When we associate a SELECT statement with more than one table joined together to a cursor with a FOR UPDATE clause, we end up locking all the tables in the FROM clause of the SELECT statement, where we just need to lock a single table for our purpose.

When we try to update the salary column of the EMPLOYEES table using the WHERE CURRENT OF clause, the block fails with an ORA-01410: invalid ROWID error as there is no way to specify the This scenario can be manhandled by fetching the rowid of the intended table in the cursor associated SELECT statement and using it in the WHERE clause of the DELETE or the UPDATE statement instead of the WHERE CURRENT OF clause as shown in the below listing. For complete notes on programming in PL/SQL, we recommend the book Advanced PL/SQL: The Definitive Reference by Boobal Ganesan.

This is a complete book on PL/SQL with everything you need to know to write efficient and complex PL/SQL code.

SQL select * from Employee 2 / ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION ---- ---------- ---------- --------- --------- ---------- ---------- --------------- 01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester 8 rows selected.

SQL DECLARE 2 CURSOR employee_cur IS 3 SELECT * FROM employee 4 FOR UPDATE OF salary; 5 BEGIN 6 FOR employee_rec IN employee_cur 7 LOOP 8 UPDATE employee 9 SET salary = 10000 10 WHERE CURRENT OF employee_cur; 11 END LOOP; 12 END; 13 / PL/SQL procedure successfully completed.

The FOR UPDATE OF clause helps us in locking up the intended table rather all available tables.

In the below example, the cursor CUR is associated with a SELECT statement having the tables EMPLOYEES and joined in its FROM clause. EMPLOYEE_ID clause in the below snippet locks up only rows of the EMPLOYEES table, thus making the DEPARTMENTS table available for modification to the other session users. For this, the cursor CUR is associated with a SELECT statement joining the EMPLOYEES and the DEPARTMENTS tables with a FOR UPDATE OF clause on the employee ID.

In the previous article (cursors overview) we have seen simple examples with SQL statements. If we want to use explicit cursor to update or delete data, we need to: -declare the cursor with FOR UPDATE clause (to avoid unwanted changes from others).

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