Oracle PL/SQL Tutorial/Transaction/Commit

Commit in a function

   <source lang="sql">

SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,

 2                    ENAME VARCHAR2(10),
 3                    JOB VARCHAR2(9),
 4                    MGR NUMBER(4),
 5                    HIREDATE DATE,
 6                    SAL NUMBER(7, 2),
 7                    COMM NUMBER(7, 2),
 8                    DEPTNO NUMBER(2));

Table created. SQL> SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK", 7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7521, "WARD", "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER", 7839, TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> SQL> SQL> CREATE TABLE query_trace (

 2     table_name VARCHAR2(30),
 3     rowid_info ROWID,
 4     queried_by VARCHAR2(30),
 5     queried_at DATE
 6     );

Table created. SQL> SQL> CREATE OR REPLACE FUNCTION traceit (

 2     tab IN VARCHAR2,
 3     rowid_in IN ROWID)
 4     RETURN INTEGER
 5  IS
 6     PRAGMA AUTONOMOUS_TRANSACTION;
 7  BEGIN
 8     INSERT INTO query_trace VALUES (tab, rowid_in, USER, SYSDATE);
 9     COMMIT;
10     RETURN 0;
11  END;
12  /

Function created. SQL> SQL> SELECT ename, traceit ("emp", ROWID)

 2    FROM emp;

ENAME TRACEIT("EMP",ROWID)

--------------------

SMITH 0 ALLEN 0 WARD 0 JONES 0 MARTIN 0 BLAKE 0 CLARK 0 SCOTT 0 KING 0 TURNER 0 ADAMS 0 JAMES 0 FORD 0 MILLER 0 14 rows selected. SQL> SQL> SELECT table_name, rowid_info, queried_by,

 2         TO_CHAR (queried_at, "HH:MI:SS") queried_at
 3    FROM query_trace;

TABLE_NAME ROWID_INFO QUERIED_BY QUERIED_

------------------ ------------------------------ --------

emp AAAE5nAABAAAKXqAAA sqle 08:08:36 emp AAAE5nAABAAAKXqAAB sqle 08:08:36 emp AAAE5nAABAAAKXqAAC sqle 08:08:36 emp AAAE5nAABAAAKXqAAD sqle 08:08:36 emp AAAE5nAABAAAKXqAAE sqle 08:08:36 emp AAAE5nAABAAAKXqAAF sqle 08:08:36 emp AAAE5nAABAAAKXqAAG sqle 08:08:36 emp AAAE5nAABAAAKXqAAH sqle 08:08:36 emp AAAE5nAABAAAKXqAAI sqle 08:08:36 emp AAAE5nAABAAAKXqAAJ sqle 08:08:36 emp AAAE5nAABAAAKXqAAK sqle 08:08:36 emp AAAE5nAABAAAKXqAAL sqle 08:08:36 emp AAAE5nAABAAAKXqAAM sqle 08:08:36 emp AAAE5nAABAAAKXqAAN sqle 08:08:36 14 rows selected. SQL> SQL> SQL> DROP TABLE query_trace; Table dropped. SQL> drop table emp; Table dropped. SQL></source>

Committing and Rolling Back a Transaction

A database transaction is SQL statements grouping as a logical unit of work.

You perform a commit with the COMMIT statement to permanently record the results of the SQL statements in a transaction.

To undo the results of the SQL statements, you perform a rollback with the ROLLBACK statement.

   <source lang="sql">

SQL> -- create demo table SQL> create table Employee(

 2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
 3    First_Name         VARCHAR2(10 BYTE),
 4    Last_Name          VARCHAR2(10 BYTE),
 5    Start_Date         DATE,
 6    End_Date           DATE,
 7    Salary             Number(8,2),
 8    City               VARCHAR2(10 BYTE),
 9    Description        VARCHAR2(15 BYTE)
10  )
11  /

Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2               values ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
 3  /