DML STATEMENTS

SELECT

Used to select particular coloumn from a table

 

Syntax: SELECT*FROM TABLE NAME;

INSERT

Used to create a row in the data base object and insert statement canhave many forms.

HOW TO INSERT MULTIPLE ROWS

 syntax:INSERT INTO TABLE NAME VALUES(V1,V2..............);

INSERT USING SUBSTITUTION VARIABLES

Syntax:INSERT INTO TABLE NAME VALUES(&COL1,&COL2.............);

HOW TO COPY ROWS FROM ONE TABLE TO OTHER

Syntax:INSERT INTO TABLE1(COL1,COL2...........) SELECT COL1,COL2.......................
            FROM TABLE2 WHERE CONDITION;

UPDATE 

used to update  existing records in the table.

syntax: UPDATE TABLE NAME SET COLOUMN NAME=VAL1,COL2=VAL2............
             WHERE CONDITION;

UPDATE 2 COLOUMNS BY USING A SUB QUERY

Syntax: UPDATE TABLE NAME SET(COL1,COL2...............)=((SUB QUERY1),(SUB             QUERY2)................) WHERE CONDITION;

DELETE

 Syntax: DELETE FROM TABLE NAME[WHERE CONDITION];
              DELETE*FROM TABLE NAME;

TRUNCATE

Used to delete all th data from particular table

syntax:truncate table table name;

MERGE

 

Used to insert new records and to update existing records based on weither or not a condition matches.

syntax: MERGE INTO TABLE NAME USING TABLE REFERENCE
            ON CONDITION WHEN MATCHED THEN UPDATE      
            SET COL1=VAL1[,......................]
            WHEN NOT MATCHED THEN INSERT[COL1,...........] VALUES[VAL1.......];