SQL Server 2012 Select query

Posted by : Sudhir Chekuri Friday, 22 November 2013

Select

select 'test'

When you execute the above select query it will print test as output

select * from tbl_register

The above query is used to print the whole table data named as tbl_register.

select name from tbl_register

The above query is used to print data of name column from table named as tbl_register.

Where

select name from tbl_register where id<3

The above query is used to print data of name column from tbl_register table with id value less than 3 only.

select id, name from tbl_register where id<3 order by name

The above query is used to print data from id and name columns and the output will be sorted based on the name column data.

Distinct

select distinct name from tbl_register

The above query will print data in name column without duplicates or repeated values.

alias

select name as username from tbl_register

select username = name from tbl_register
select name username from tbl_register

The above three queries will print data in name column with username as column name.

select name from tbl_register as register

select name from tbl_register register

The above two queries will create register as alias name for table name tbl_register which is used in joins.

case

select id, name,

case stat

when 'yes' then 'pass'

else 'fail'

end as

[status]

from tbl_register

The above query will print three columns id, name, status.
id, name columns data is printed along with one more column named as status which is not present in table.
the data under status column is based on stat column which is present under tbl_register.
if stat column value is yes then at that place pass is printed else fail is printed in status column in the output.

id name status

1 sudhir pass

2 raj fail

3 ram pass

4 gopi pass

5 sudhir fail