SQL Server is a powerful relational database management system that is widely used in the industry. It offers a wide range of features and functionalities that make it a popular choice for storing and managing data. In this article, we will discuss some important concepts and ideas related to SQL Server.

Renaming a Database

One common task in SQL Server is renaming a database. This can be done using the sp_renamedb command. For example, to rename a database from ‘oldname’ to ‘newname’, you can use the following command:

sp_renamedb 'oldname', 'newname'

However, if the database is currently being used by someone, the sp_renamedb command will not work. In that case, you need to first bring the database to single user mode using the sp_dboptions command, and then use the sp_renamedb command to rename the database.

Configuring Server-Level Settings

SQL Server provides the sp_configure command to display or change server-level settings. If you want to change database-level settings, you can use the ALTER DATABASE command. And if you want to change settings that affect only the current user session, you can use the SET statement.

Types of Replication

SQL Server supports different types of replication, including:

• Transactional replication
• Snapshot replication
• Merge replication

Transactional replication involves capturing and propagating individual transactions from the publisher to the subscribers. Snapshot replication distributes data exactly as it appears at a specific moment in time. Merge replication allows the publisher and subscribers to make updates while connected or disconnected, and then merges the updates between sites when they are connected.

OS Services Added by SQL Server Installation

When you install SQL Server, it adds several OS services, including:

• MS SQL SERVER SERVICE
• SQL AGENT SERVICE
• DTC (Distribution transac co-ordinator)

These services are essential for the proper functioning of SQL Server.

Managing Permissions

There are three SQL keywords used to change or set someone’s permissions:

• GRANT
• DENY
• REVOKE

These keywords allow you to grant or revoke specific permissions to users or roles in SQL Server.

Quoted Identifier

The QUOTED_IDENTIFIER setting in SQL Server determines how identifiers and literals are delimited. When QUOTED_IDENTIFIER is ON, identifiers can be delimited by double quotation marks, and literals must be delimited by single quotation marks. When QUOTED_IDENTIFIER is OFF, identifiers cannot be quoted and must follow all Transact-SQL rules for identifiers.

STUFF Function vs REPLACE Function

The STUFF function and the REPLACE function are used to modify strings in SQL Server. The STUFF function is used to overwrite existing characters in a string, while the REPLACE function is used to replace existing characters with new characters. The syntax for using these functions is different, so make sure to use the correct one based on your requirements.

Getting an Accurate Count of Records

There are several ways to get an accurate count of the number of records in a table in SQL Server. Here are three common methods:

1. Using the SELECT * statement to retrieve all records from the table.
2. Using the SELECT COUNT(*) statement to count the number of records in the table.
3. Using the SELECT rows FROM sysindexes WHERE id = OBJECT_ID('table1') AND indid < 2 statement to retrieve the number of rows from the system table.

Rebuilding the Master Database

If you need to rebuild the master database in SQL Server, you can follow these steps:

1. Shutdown Microsoft SQL Server.
2. Run Rebuildm.exe, which is located in the Program Files\Microsoft SQL Server\80\Tools\Binn directory.
3. In the Rebuild Master dialog box, click Browse and select the \Data folder on the SQL Server 2000 compact disc or in the shared network directory from which SQL Server 2000 was installed.
4. Click Settings to verify or change the collation settings used for the master database and all other databases.
5. Click Rebuild to start the process. Note that you may need to stop a server that is running.

Understanding Database Functions

In SQL Server, there are several important databases that serve different purposes:

• The Master database holds information for all databases located on the SQL Server instance and is essential for the functioning of the engine.
• The msdb database stores information regarding database backups, SQL Agent information, DTS packages, SQL Server jobs, and some replication information.
• The tempdb holds temporary objects such as global and local temporary tables and stored procedures.
• The model database is essentially a template database used in the creation of any new user database created in the instance.

Primary Keys and Foreign Keys

Primary keys and foreign keys are important concepts in relational databases:

A primary key is a unique identifier for each row in a table. It must contain unique values and cannot be null. A table can have only one primary key.

A foreign key is a column or a set of columns in a table that points to the primary key of another table. It establishes a relationship between the two tables and ensures data integrity.

Data Integrity and Constraints

Data integrity is crucial in SQL Server to ensure that data is accurate, correct, and valid. Constraints are used to enforce data integrity. Here are some common types of constraints:

• A PRIMARY KEY constraint is a unique identifier for a row within a database table.
• A UNIQUE constraint enforces the uniqueness of values in a set of columns.
• A FOREIGN KEY constraint prevents actions that would destroy links between tables.
• A CHECK constraint limits the values that can be placed in a column.
• A NOT NULL constraint enforces that a column will not accept null values.

By using these constraints, you can ensure the integrity of your data and prevent any inconsistencies or errors.

These are just a few concepts and ideas related to SQL Server. The platform offers many more features and functionalities that can help you effectively manage your data. Stay tuned for more articles on SQL Server!