ACTION QUERIES

(SQL COMMANDS)

STRUCTURED QUERY LANGUAGE

ACTION QUERIES (SQL COMMANDS)

DATA DEFINITION LANGUAGEDATA MANIPULATION LANGUAGETRANSACTION CONTROL LANGUAGEDATA CONTROL LANGUAGE

DATA DEFINITION LANGUAGE (DDL)

CREATEALTERDROP TRUNCATE

DATA MANIPULATION LANGUAGE

(DML)

INSERTUPDATEDELETE

TRANSACTION CONTROL LANGUAGE

(TCL)

COMMITROLLBACKSAVEPOINT

DATA CONTROL LANGUAGE (DCL)

GRANTREVOKE

DATA TYPESNUMBER (FLOAT)

VARCHAR2

DATE

40 DIGITS +SPACE FOR A DECIMAL AND A SIGN

UPTO 4000 BYTES

7 DIGITS

TO CREATE A TABLE

CREATE TABLE TABLENAME(ATTRIBUTE1 DATATYPE, ATTRIBUTE2 DATATYPE,....);

TO ALTER A TABLE & ADD A COLUMNALTER TABLE TABLENAME ADD ATTRIBUTE DATATYPE;

TO VIEW THE TABLE

SELECT * FROM TABLENAME;

TO ALTER A TABLE AND MODIFY DATATYPE

Alter table tablename modify attribute datatype; (PROVIDED THERE IS NO VALUE IN THE COLUMN)

TO RENAME A TABLE

Rename oldtablename to newtablename;

TO DROP A TABLE

Drop table tablename;

TO TRUNCATE A TABLE

TRUNCATE TABLE TABLENAME;

To insert values into a table

INSERT INTO TABLENAME VALUES(VALUE1,VALUE2,VALUE3....);

TO UPDATE VALUES

Update tablename set column1=value1, column2=value2 where columnname=value;

To delete values from a table

Delete from tablename where columnname=value;

TO SAVE CHANGES PERMANENT/ TEMPORARY

COMMIT;ROLLBACK;SAVEPOINT;

EXAMPLES FOR COMMIT AND ROLLBACK

SELECT * FROM EMP;DELETE FROM EMP;Insert into emp(empno) values(1000);

COMMIT; (CHANGES ARE PERMANENT)Insert into emp(empno) values(4000);DELETE FROM EMP;

ROLLBACK; (CHANGES MADE AFTER THE COMMIT OR DDL WILL GET ERASED)

EXAMPLES OF COMMIT, ROLLBACK AND SAVEPOINTUPDATE EMP SET EMPNO=4000 WHERE EMPNO=5000;SAVEPOINT A;INSERT INTO EMP(EMPNO) VALUES(1000);SAVEPOINT B;

INSERT INTO EMP(ENAME) VALUES(‘JAGAN’);ROLLBACK TO B; (CHANGES MADE AFTER THE ROLLBACK B WILL GET ERASED)ROLLBACK TO A; (CHANGES MADE AFTER THE ROLLBACK A WILL GET ERASED)

TO VIEW ROWS WITH SALARY BETWEEN 2000 & 4000

Select ename, sal from ex16 where sal between 2000 and 4000;

TO VIEW PERSONS WHOSE NAME HAS LETTER “A”

Select ename from ex16 where ename like ‘%a%’;

TO VIEW PERSONS WHOSE NAME STARTS WITH LETTER “A”

Select ename from ex16 where ename like ‘a%’;

FUNCTIONS

AGGREGATE FUNCTIONS

MAX (TO FIND THE MAXIMUM VALUE ON THE SET OF VALUES)

Select max(salary) from emp;

MIN (TO FIND THE MINIMUM VALUE ON THE SET OF VALUES)

SELECT MIN(SALARY) FROM EMP;

MORE EXAMPLES

SELECT ENAME, HIREDATE FROM EMP WHERE ENAME<>’RAMAN’ AND DEPTNO=(SELECT DEPTNO FROM EMP WHERE ENAME=‘ASHOK’;

MORE EXAMPLES

SELECT EMPNO, ENAME, SAL FROM EMP WHERE SAL>(SELECT AVG(SAL) FROM EMP) ORDER BY SAL DESC;

MORE EXAMPLES

SELECT EMPNO, ENAME FROM EMP WHERE DEPTNO IN (SELECT DEPTNO FROM EMP WHERE ENAME LIKE ‘%T%’);

MORE EXAMPLES

SELECT ENAME, DEPTNO, JOB WHERE DEPTNO=(SELECT DEPTNO FROM DEPT WHERE LOC=‘DALLAS’);

MORE EXAMPLES

SELECT ENAME, SAL FROM EMP WHERE MGR=(SELECT EMPNO FROM EMP WHERE ENAME=‘KING’);

MORE EXAMPLES

SELECT DEPTNO, ENAME, JOB FROM EMP WHERE DEPTNO=(SELECT DEPTNO FROM DEPT WHERE DNAME=‘SALES’);

MORE EXAMPLES

SELECT ENAME, HIREDATE FROM EMP WHERE HIREDATE=(SELECT MAX(HIREDATE) FROM EMP;

MORE EXAMPLES

SELECT EMPNO, ENAME FROM EMP WHERE DEPTNO IN (SELECT DEPTNO FROM EMP WHERE ENAME LIKE ‘%T%’ AND SAL>(SELECT AVG(SAL) FROM EMP));

MORE EXAMPLES

SELECT ENAME, DEPTNO, SAL FROM EMP WHERE (DEPTNO, SAL) IN (SELECT DEPTNO, SAL FROM EMP WHERE COMM IS NOT NULL);

MORE EXAMPLES

SELECT ENAME, JOB, SAL FROM EMP WHERE SAL>ANY(SELECT SAL FROM EMP WHERE JOB=‘CLERK’) ORDER BY SAL DESC;