4 DML Commands in SQL with Syntax and Example

Here we are going see some useful basic SQL DML commands with syntax and example, which are used frequently while working on SQL. These DML (Data Manipulation Language) Commands are very useful for making changes in table in them. Following are DML commands with syntax and example

List of DML commands:

•         Select
•         Insert
•         Update
•         Delete

Select:

Select statement is used to fetch data from table. If you want to fetch all columns you don’t need to write all column names you can use * instead. It also considered as Data Query language.

Syntax:

Select * from tablename;

          Or

Select Column1, column2, column3 from tablename;

Example:

Select * from Employee;

      

Select ID, First_name, Salary from Employee;

Insert:

Insert into statement is used to insert rows in the table.

If we want to insert data in all the columns then don’t need to specify each column name and its datatype after insert into statement just by following it’s sequence you can add values. But when you want to insert only few columns and keep other as it is you need to mention column name and datatype after insert into statement.

Syntax:

Insert into tablename

(column1 datatype, column2 datatype, column3 datatype)

Values

(value1, value2, value3);

                

Insert into tablename

Values

(Value1, value2, value3, value4, value5, value6);

  

Example:

Insert into Employee

(ID, First_name, Salary)

Values

(111, ‘Nisha’,11000);

Update:

Update is use to modify existing record in the table.

Syntax:

Update tablename

Set column1= value1, column2 = value2

Where condition;

Example:

Update Employee

Set Salary = 16000, First_name= ‘Raj’

Where ID = 102;

Delete:

Delete is use to delete required rows or all table. Delete can be used with where condition.

There we always read that we can rollback delete operation but it is only possible when you are using full recovery model or transaction process. So you can not generally recover all your deleted data as you think after reading that you can rollback delete operation.

Syntax:

Delete from tablename;

            

Delete from tablename

Where column1 = value1;

Example:

Delete from Employee;

            

Delete from Employee

Where ID = 111;

There are Many other commands used in SQL for learning them check next tutorial....