3-sql command

Some of the most important SQL commands

• SELECT -Extract data from the database
• Update-Updates the data in the database
• Delete-deletes data from the database
• INSERT INTO-inserts new data into the database
• CREATE database-creating new databases
• alter database-Modify Databases
• CREATE TABLE-Creates a new table
• ALTER TABLE -Change (change) database table
• Drop Table-delete tables
• CREATE index-Creating indexes (search key)
• Drop Index-delete indexes

1 Select

Distinct

2 where

The following operators can be used in the WHERE clause: SQL uses single quotation marks to wrap text values (most database systems also accept double quotes). If it is a numeric value, do not use quotation marks.

operator	Description
=	Equals
<>	Not equal to
>	Greater than
<	Less than
>=	Greater than or equal
<=	Less than or equal
Between	Within a range
Like	Search for a pattern

The and and or operators are used to filter records based on more than one condition.

eg

(ORFirstname= ' William ' ) AND lastname= ' Carter '

3 ORDER BY

3-sql command