Dale Roberts 1 Department of Computer and Information Science, School of Science, IUPUI Dale Roberts, Lecturer Computer Science, IUPUI Data Manipulation Language Insert, Updates, Deletes

Dale Roberts 2 Data Manipulation Language StatementsInsertRollbackCommitUpdateMergeDelete Transaction Management allows for read-consistent views. Data is but published to other users until it is committed. Allow uncommitted transactions to be rolled back.

Dale Roberts 3 Insert Allows you to insert a row or rows into tables or views. Syntax1: INSERT INTO tablename / viewname ( column1, column2,... ) ( column1, column2,... ) VALUES ( value1, value2,... ); VALUES ( value1, value2,... );Syntax2: INSERT INTO tablename / viewname ( column1, column2,... ) ( column1, column2,... ) subquery ; subquery ; Column names are optional, but then the values must be in order of the columns.

Dale Roberts 4 Insert Examples The following statement inserts a row into the DEPT table: INSERT INTO dept VALUES (50, ’PRODUCTION’, ’SAN FRANCISCO’); VALUES (50, ’PRODUCTION’, ’SAN FRANCISCO’); The following statement inserts a row with six columns into the EMP table. One of these columns is assigned NULL and another is assigned a number in scientific notation: INSERT INTO emp (empno, ename, job, sal, comm, deptno) VALUES (7890, ’JINKS’, ’CLERK’, 1.2E3, NULL, 40); INSERT INTO emp (empno, ename, job, sal, comm, deptno) VALUES (7890, ’JINKS’, ’CLERK’, 1.2E3, NULL, 40); The following statement copies managers and presidents or employees whose commission exceeds 25% of their salary into the BONUS table: INSERT INTO bonus SELECT ename, job, sal, comm FROM emp WHERE comm > 0.25 * sal OR job IN (’PRESIDENT’, ’MANAGER’);

Dale Roberts 5 Insert with Append Hint To improve insert performance, especially for large subquery inserts, you can use the /*+ APPEND */ hint. Insert /*+ APPEND */ into mytable (col1) select mycol from othertable; Normally insert looks for freespace inside currently allocated blocks on disk. Append overrides this behavior and appends data to the table by allocating new data blocks. Hints are non-ANSI standard. This only works in Oracle.

Dale Roberts 6 Rollback, Commit, Autocommit Rollback allow you to reverse changes. Commit make your changes permanent.

Dale Roberts 7 Transactions, Savepoint Transactions begin when: a SQL satatement is first issued, immediately after a commit, immediately after a rollback. Commits occur when: Commit (explicit) quit/exit a program (implicit) DDL (implicit) Rollbacks occur when: Rollback (explicit) Abnormal program termination (implicit) Database crash (implicit)  SAVEPOINT allows you to rollback to a specific point in a transaction. Example: UPDATE emp SET sal = 2000 WHERE ename = ’BLAKE’; SAVEPOINT blake_sal UPDATE emp SET sal = 1500 WHERE ename = ’CLARK’; SAVEPOINT clark_sal SELECT SUM(sal) FROM emp; ROLLBACK TO SAVEPOINT blake_sal; UPDATE emp SET sal = 1300 WHERE ename = ’CLARK’; COMMIT;

Dale Roberts 8 Delete, Update Examples The following statement deletes all rows from a table named TEMP_ASSIGN. DELETE FROM temp_assign; The following statement deletes from the employee table all sales staff who made less than $100 commission last month: DELETE FROM emp WHERE JOB = ’SALESMAN’ AND COMM < 100; The following statement gives null commissions to all employees with the job TRAINEE: UPDATE emp SET comm = NULL WHERE job = ’TRAINEE’; The following statement promotes JONES to manager of Department 20 with a $1,000 raise: UPDATE emp SET job = ’MANAGER’, sal = sal , deptno = 20 WHERE ename = ’JONES’;

Dale Roberts 9 Update Example More complex example with multiple subqueries. UPDATE emp a SET deptno = SET deptno = (SELECT deptno (SELECT deptno FROM dept FROM dept WHERE loc = ’BOSTON’), WHERE loc = ’BOSTON’), (sal, comm) = (sal, comm) = (SELECT 1.1*AVG(sal), 1.5*AVG(comm) (SELECT 1.1*AVG(sal), 1.5*AVG(comm) FROM emp b FROM emp b WHERE a.deptno = b.deptno) WHERE a.deptno = b.deptno) WHERE deptno IN (SELECT deptno (SELECT deptno FROM dept FROM dept WHERE loc = ’DALLAS’ WHERE loc = ’DALLAS’ OR loc = ’DETROIT’); OR loc = ’DETROIT’);

Dale Roberts 10 Multi-table Inserts Multi-table inserts are a new 9i feature. WHEN clause indicates which VALUES clause to use. ALL or FIRST indicates to evaluate all or only the first WHEN/VALUE clause per row. Insert ALL|FIRST when (condition1) then insert clause1 when (condition2) then insert clause2 when (condition2) then insert clause2 when (condition3) then insert clause3 when (condition3) then insert clause3else insert clause4 insert clause4Subquery;

Dale Roberts INSERT ALL Example 11 INSERT ALL INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) VALUES(TITLE, PUBLISHER, CATEGORYNAME, 5) VALUES(TITLE, PUBLISHER, CATEGORYNAME, 5) INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) VALUES(TITLE || '-1', PUBLISHER, CATEGORYNAME, 4) VALUES(TITLE || '-1', PUBLISHER, CATEGORYNAME, 4) INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) INTO BOOKSHELF(TITLE, PUBLISHER, CATEGORYNAME, RATING) VALUES(TITLE || '-2', PUBLISHER, CATEGORYNAME, 3) VALUES(TITLE || '-2', PUBLISHER, CATEGORYNAME, 3)SELECT 'MY FIRST BOOK' TITLE, 'MY FIRST BOOK' TITLE, 'RANDOM PRESS' PUBLISHER, 'RANDOM PRESS' PUBLISHER, 'ADULTFIC' CATEGORYNAME 'ADULTFIC' CATEGORYNAME FROM DUAL; FROM DUAL;

Dale Roberts Merge Merge is a new 9i feature, commonly called UPSERT. Combines the features of an INSERT with UPDATE. Based on the conditions you specify in the WHEN clause, Oracle takes the source data (table, view, subquery) and updates the existing rows. If the conditions are not met, a new row is inserted. MERGE into COMFORT C1 USING (select City, SampleDate, Noon from COMFORT) C2 ON (C1.City=C2.City and C1.SampleDate=C2.SampleDate) WHEN MATCHED THEN update set C1.Noon = C2.Noon WHEN NOT MATCHED THEN insert (C1.City, C1.SampleDate, C1.Noon) values (C2.City, C2.SampleDate, C2.Noon);

Dale Roberts 13 Acknowledgements Loney, Oracle Database 10g The Complete Reference