Getting information about all tables in an SQL database is a common necessity while working as a developer or database administrator. It allows us to manage, design, and control data flow efficiently. This article will demonstrate how you can fetch these details using SQL code.
Fetching all table details is quite simple. In SQL, the Information Schema is generally used. Information Schema in SQL is basically a set of views and tables to provide information about the database. We can call it a database about databases.
To get details about all tables, we use the ‘TABLES’ view of ‘INFORMATION_SCHEMA’. The TABLES view provides the description of all tables in a database.
SELECT * FROM INFORMATION_SCHEMA.TABLES;
When you run this SQL query, it fetches details for every table in your current database.
Breaking Down the Code
This SQL code is quite straightforward. The SELECT * statement is used to select all fields. In this case, it’s selecting every field from each record of the specified table.
The FROM keyword is used to specify the table from which you want to retrieve data. Here, INFORMATION_SCHEMA.TABLES is the specified table. Hence, the query fetches every field of each record from this table.
As we delve deeper into SQL’s INFORMATION_SCHEMA, it’s important to understand its significance. The ‘INFORMATION_SCHEMA’ is essentially a collection of views and tables in SQL which provide information about the database.
- It exists within each database and is always up-to-date. As changes occur in the database, INFORMATION_SCHEMA reflects them immediately.
- It adheres to the ANSI SQL standard, which means it’s supported by most relational database management systems (RDBMS), making it a portable and consistent method for meta-data querying.
- By querying INFORMATION_SCHEMA, users can obtain valuable information like the name of a database, its tables, columns, data types, and constraints without having to sift through actual data.
Managing data with SQL
Understanding SQL’s capabilities, like fetching all tables, provides a powerful mechanism for managing our data. Database administrators and developers often need to extract and manipulate database schemas. Queries like the one above, using SQL’s INFORMATION_SCHEMA, make these tasks manageable.
As we progress our knowledge in SQL, additional commands and functions will continue to build upon these fundamentals, enhancing our control over data and database structures. This awareness, along with proficient practice, can lead to efficient database management, keeping the system robust and optimized.