How to use SQL’s Information Schema In SQL
The Information Schema gives details about the database. For example, it shows information about tables, columns, and data types. You can check the INFORMATION_SCHEMA.COLUMNS view to learn about columns. This view shows you what columns exist in each table.
Syntax:
SELECT COLUMN_NAME, DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = ‘YourTableName’;
Replace ‘YourTableName‘ with the name of the table whose column types you want to retrieve.
Created Table
Now, if we want to see the Type of columns.
SELECT COLUMN_NAME, DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'customer' ;
Output:
Also, you can find for particular column by adding COLUMN_NAME=’NameOfColumn’;
Example: Retrieving Column Type Using SQL’s Information Schema
SELECT COLUMN_NAME, DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'customer' AND COLUMN_NAME = 'Country';
Output:
Explanation: This query retrieves the column name and data type from the “customer” table where the column name is “Country” using SQL’s Information Schema.
How to Get the Type of Columns in SQL
In SQL, the types of columns in a database table play a fundamental role in data management and query execution. Each column is designed to store specific types of data, such as numbers, text, dates, or binary data. Understanding these column types is essential for effective database design, query optimization, and ensuring data integrity.
In this article, we cover retrieving column types in SQL using three methods: SQL’s Information Schema, the DESCRIBE statement, and Database GUI Tools. Each method offers insights into column types, aiding effective data management. Output includes detailed information about column data types, facilitating database schema understanding and query optimization.