What is the T-SQL To grant read and write access to tables in a database in SQL Server?

Question

What is the exact SQL to assign db_datareader and db_datawriter roles to a user in SQL Server?

The user name is MYUSER and the database is MYDB.

Answer 1

In SQL Server 2012, 2014:

USE mydb GO  ALTER ROLE db_datareader ADD MEMBER MYUSER GO ALTER ROLE db_datawriter ADD MEMBER MYUSER GO 

In SQL Server 2008:

use mydb go  exec sp_addrolemember db_datareader, MYUSER  go exec sp_addrolemember db_datawriter, MYUSER  go 

To also assign the ability to execute all Stored Procedures for a Database:

GRANT EXECUTE TO MYUSER; 

To assign the ability to execute specific stored procedures:

GRANT EXECUTE ON dbo.sp_mystoredprocedure TO MYUSER; 

Answer 2

From SQLServer 2012 more elegant alter role:

use mydb go  ALTER ROLE db_datareader   ADD MEMBER MYUSER  go ALTER ROLE db_datawriter   ADD MEMBER MYUSER  go