ALTER TABLE/ORDER BY CLAUSE

In this post , we will be knowing use of ALTER command on table. The ALTER command is used to change the structure of the table. For ex Adding a column, Deleting a column, Or Changing the Data Type of the column etc.

• Changing data type of column.

In above figure , we see that the data type of age is int. Let's change it to varchar(10)

ALTER TABLE Winform_1
ALTER column Age varchar(10)

Data type of Age is changed.

The ALTER table syntax is different for MYSQL , DB2 etc.

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• Adding column to table.

To add the column to the table , following ALTER command is used.

ALTER TABLE WinForm_1
ADD address varchar(20)

Column address is added.

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• Dropping a column.

Using ALTER command , we can also drop or delete column from the table. See the below command to know how can we do it.

ALTER table WinForm_1
DROP column address

In this post, we will be studying order by clause. The order by is used to select data from database in particular order or particular column.

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Syntax

SELECT column_name1,column_name2 from table_name
ORDER BY column_name ASC|DESC

Note- If you omit ASC keyword from order by clause , it will sort in ascending order by default.

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ID	Name	City	State
1	Raj	Mumbai	Maharashtra
2	Rahul	Nashik	Maharashtra
3	Saurabh	Nagar	Maharashtra
4	Ryan	panaji	Goa

Example

SELECT * from Detail ORDER BY ID desc

Output.

ID	Name	City	State
4	Ryan	panaji	Goa
3	Saurabh	Nagar	Maharashtra
2	Rahul	Nashik	Maharashtra
1	Raj	Mumbai	Maharashtra

We can also use multiple columns in order by clause.
For example, Consider the following table.

ID	Name	State
1	Anoop	Delhi
2	Ankit Pandey	Pune
3 4	Gaurav Kapoor Arjit Singh	Delhi Punjab

Example

SELECT * FROM [dbo].[tbl_Record] order by Name,State

Output

ID	Name	State
1	Anoop	Delhi
2	Ankit Pandey	Pune
3 4	Gaurav Kapoor Arjit Singh	Delhi Punjab