Database Level Fixed Roles

DB Levek Fixed Roles	Rights and Description
db_accessadmin	Members can manage Windows groups and SQL Server logins.
db_backupoperator	Issue DBCC, CHECKPOINT, and BACKUP statements.
db_datareader	Select all data from any user table in the database
db_datawriter	Modify any data in any user table in the database
db_ddladmin	Issue all Data Definition Language (DDL) statements
db_denydatareader	Cannot select any data from any user table in the database
db_denydatawriter	Cannot modify any data in any user table in the database
db_owner	Has full permissions to the database
db_securityadmin	Members can modify role membership and manage permissions.