Managing the Data SQL Overview

Client\Server RDMS (relational database management system) Client\Server RDMS (relational database management system) Commands are sent to the server and answers are returned to the client Commands are sent to the server and answers are returned to the client Very efficient – low network traffic Very efficient – low network traffic The server does most of the work The server does most of the work Very stable (unsuccessful transactions rollback) Very stable (unsuccessful transactions rollback) SQL is the industry standard Servers SQL is the industry standard Servers

SQL Server It is the only thing that touches the data It is the only thing that touches the data The data is under the server’s control The data is under the server’s control

MSDE – Microsoft Desktop Engine Freely distributable Freely distributable Limited to 5 connections or less Limited to 5 connections or less Can be installed with ComCash Can be installed with ComCash

Microsoft SQL Server Includes many tools Includes many tools DTS – Data Transformation Services DTS – Data Transformation Services Query Analyzer Query Analyzer Enterprise Manager Enterprise Manager No connection limitation No connection limitation Must be purchased and installed separately Must be purchased and installed separately

Default Server vs. Named Instance Default Server installation Default Server installation Server name = computer name Server name = computer name Named instance (ComCash installs as a named instance) Named instance (ComCash installs as a named instance) Server name = computer name\instance name (computer name\comcash) Server name = computer name\instance name (computer name\comcash)

Logon and Connections TCP/IP connections only TCP/IP connections only Default system administrator logon Default system administrator logon Username = sa Username = sa Password = null (blank password) Password = null (blank password)

Database Files Files.mdf file = Primary data file - stores the system tables and the data.mdf file = Primary data file - stores the system tables and the data.ldf file = Transaction log files - used to store transaction information and can be used to recover the database.ldf file = Transaction log files - used to store transaction information and can be used to recover the database

Attached vs. Detached Never copy, delete, rename, or move.mdf/.ldf files unless detached Never copy, delete, rename, or move.mdf/.ldf files unless detached

Sample Data vs. Production Sample data is used only for evaluation Sample data is used only for evaluation The data can be backed up and restored to the comcash database The data can be backed up and restored to the comcash database Live installations always use comcash (Production) database Live installations always use comcash (Production) database In multiple database installations one might see comcash01, comcash02, etc In multiple database installations one might see comcash01, comcash02, etc

Tables Rows and Columns (or records and fields) Rows and Columns (or records and fields) Keys (tables typically have a key the guarantees uniqueness) Keys (tables typically have a key the guarantees uniqueness)