PPT ON DML COMMANDS

1. Govt First Grade College Chikkabasur
Department of Computer Applications
CLASS : Bcom III Year
SUBJECT : Computer Applications In Business
TOPIC NAME : DML (Data Manipulation Language) Commands
Presented By : Prof.Rakesh Shettar
Dept of Computer Applications

2. DML (Data Manipulation Language)
DML Commands are most frequently used SQL Commands.
They are used to query & manipulate existing objects like tables.
COMMANDS IN DML:
1. INSERT Command
2. SELECT Command
3. UPDATE Command
4. DELETE Command

3.  INSERT Command:
Once creation of the table is completed, it remains a skeletal structure
unless it is populated with rows. The insert command is used to add one or
more rows to a table.
Syntax:
insert into <table_name> values (value_list);
Ex:
insert into emp values(123,‘prasad’,22,15000);

4.  SELECT Command:
SELECT supports the data retrieval. Data retrieval allows a user or an
application program to retrieve stored data from the database & use it.
Syntax:
Select <column_name> from <table_name>;
Ex:
Select name from emp;

5.  UPDATE Command:
UPDATE modifies the values of one or more columns in selected rows
of a table. The table to updated is named in the statement. The where clause
selects the rows of the table to modified. The set specifies which columns are to
be updated & calculates the new values from them.
Syntax:
Update <table_name> set <column_name1> = <value1>,
<column_name2> = <value2>………where <logical_expression>;
Ex:
Update emp set salary=20000 where name=’prasad’ ;

6.  DELETE Command:
Removing rows from the tables in SQL is easier than inserting them.
To delete rows we can use the DELETE Command. Again the where
clause is essential to delete. If we use the delete command without the
where clause, the contents of the entire table will be deleted.
Syntax:
Delete from <table_name> where <logical_expression>;
Ex:
Delete from emp where age=22;