Understanding SQL Server Information_Schema for Dev

Welcome, Dev! If you’re looking for ways to improve your SQL Server skills, then you’ve come to the right place. In this article, we’ll be talking about the Information_Schema, a set of views that provide valuable metadata about your SQL Server database. We’ll be going through the basics, including what it is, what it contains, and how it can be used to optimize your database performance. So without further ado, let’s dive in!

What is Information_Schema?

The Information_Schema is a set of views that provide information about your SQL Server database. It is a collection of system views that expose metadata about your database objects, such as tables, columns, views, and constraints. These views are implemented as tables, and they can be queried just like any other table.

One of the benefits of Information_Schema is that it provides a consistent way to access metadata across different database platforms. This means that you can use the same queries to retrieve metadata from different database systems, such as Oracle, MySQL, and SQL Server.

What does Information_Schema contain?

Information_Schema contains information about the following database objects:

How can Information_Schema be used?

Information_Schema provides a wealth of information about your database objects, and it can be used for a variety of purposes, including:

1. Database Documentation

Information_Schema can be used to generate documentation for your database objects. You can use the views to retrieve information about tables, columns, views, and constraints, and then use that information to generate documentation in a format that is easy to read and understand.

2. Query Optimization

Information_Schema can be used to optimize your queries by providing information about the structure of your database. For example, you can use the columns view to retrieve information about the data types and constraints of the columns in a table, and use that information to optimize your queries.

3. Database Migration

Information_Schema can be used to migrate your database from one platform to another. Since Information_Schema provides a consistent way to access metadata across different platforms, you can use the same queries to retrieve metadata from different platforms, and use that information to migrate your database to a new platform.

4. Data Validation

Information_Schema can be used to validate data in your database. For example, you can use the constraints view to retrieve information about the constraints in a table, and then use that information to validate the data in the table.

5. Security Auditing

Information_Schema can be used for security auditing. For example, you can use the views to retrieve information about users and permissions in your database, and use that information to audit your database security.

How to use Information_Schema

Using Information_Schema is easy. To use Information_Schema, you simply need to query one of the views. For example, to retrieve information about columns in a table, you can use the columns view:

SELECT column_name, data_type, character_maximum_length, is_nullable, column_default FROM information_schema.columns WHERE table_name = 'employees'

This query retrieves information about the columns in the employees table, including the column name, data type, maximum length, nullability, and default value.

FAQ

1. Can I modify data using Information_Schema?

No, Information_Schema is read-only. You cannot modify data using Information_Schema. If you need to modify data, you will need to use DML statements, such as INSERT, UPDATE, and DELETE.

2. What is the difference between Information_Schema and sys schema?

The sys schema is a set of views that provide more detailed metadata about your SQL Server database. Information_Schema provides a more concise set of views that are consistent across different database platforms. If you need more detailed metadata about your SQL Server database, you can use the sys schema.

3. Can I use Information_Schema with other database platforms?

Yes, Information_Schema is a standard across different database platforms. You can use the same queries to retrieve metadata from different platforms, such as Oracle, MySQL, and SQL Server.

4. Can I use Information_Schema to retrieve information about database users?

Yes, you can use the views in Information_Schema to retrieve information about database users and permissions. For example, you can use the tables_priv view to retrieve information about the privileges that users have on tables in your database.

5. Can I use Information_Schema to retrieve information about stored procedures?

Yes, you can use the routines view to retrieve information about stored procedures and functions. The routines view provides information about routine name, routine type, and routine schema.

That’s all for this article, Dev. We hope that this has been informative and helpful in your quest to become a SQL Server expert. Remember, Information_Schema is a powerful tool that can help you optimize your database performance and make your life easier. If you have any questions, feel free to ask in the comments section below. Happy querying!