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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;