chetnashah / sqlwork

sql tutorial

AS statement

3 use cases:

1. column name alias
2. table name alias
3. Temporary table creation using: WITH alias_name AS (subquery_stmt)

Where IN

Used for querying in subquery: select * from abc where abc.id in (sub_query or list)

Group BY

Groupby can be done on 1 column or multiple columns, Need to use aggregate functions like Max, Cnt, Avg with group by

Variables using SET

Set variables using SET and use them using $name

Distinct

distinct can be done on one or multiple columns. in case of multiple columns, The combination unique is shown.