SQL statement overview

SELECT -- retrieve data rows and columns from database tables
INSERT -- add new data rows to the database table
DELETE -- DELETE data rows from a database table
UPDATE -- UPDATE data in the database table

-- Data Definition
Create table -- CREATE a database TABLE
Drop table -- delete a TABLE from a database
Alter table -- modify the database TABLE structure
Create view -- CREATE a VIEW
Drop view -- delete a VIEW from a database
Create index -- CREATE an INDEX for the database table
Drop index -- delete an INDEX from a database
Create procedure -- CREATE a stored PROCEDURE
Drop procedure -- delete a stored PROCEDURE from a database
Create trigger -- CREATE a TRIGGER
Drop trigger -- delete a TRIGGER from a database
Create schema -- add a new SCHEMA to the database
Drop schema -- delete a SCHEMA from the database
Create domain -- CREATE a data value DOMAIN
Alter domain -- change DOMAIN definition
Drop domain -- delete a DOMAIN from the database

-- Data control
GRANT -- GRANT the user access permission
DENY-DENY user access
REVOKE -- REVOKE user access permissions

-- Transaction control
COMMIT -- end the current transaction
ROLLBACK -- abort the current transaction
Set transaction -- define the data access features of the current TRANSACTION

-- Programmatic SQL
DECLARE -- set the cursor for the query
Explain -- describe the data access plan for query
OPEN -- OPEN a cursor for retrieving query results
FETCH -- retrieve a row of query results
CLOSE -- CLOSE the cursor
PREPARE -- prepare SQL statements for dynamic execution
EXECUTE -- dynamically execute SQL statements
DESCRIBE -- DESCRIBE the prepared query --- local variables
Declare @ id char (10)
-- Set @ id = '000000''
Select @ id = ''10010001'' --- Global variable
--- It must start with @ -- IF ELSE
Declare @ x int @ y int @ z int
Select @ x = 1 @ y = 2 @ z = 3
If @ x> @ y
Print ''X> y'' -- print the string ''X> y''
Else if @ y> @ z
Print ''Y> Z''
&