What Type of Query Changes Data?
When working with databases, it’s important to understand the different types of queries and their impact on data. While some queries are used for retrieving information, others are designed to modify or change data within a database.
In this article, we will focus on the latter category – queries that change data.
The INSERT query is used to add new records to a database table. It allows you to specify the values for each column in the table, and the database will create a new row with those values.
This query is often used when adding new users, products, or any other type of data that needs to be stored in the database.
The UPDATE query is used to modify existing records in a database table. It allows you to change the values of one or more columns in one or multiple rows.
This query is commonly used when updating user profiles, changing product prices, or editing any other type of stored information.
The DELETE query is used to remove records from a database table. It allows you to specify criteria for selecting which rows should be deleted.
This query should be executed with caution as it permanently removes data from the database. It’s often recommended to perform backups before executing delete queries.
The MERGE query is less commonly used but can be very powerful when dealing with large datasets. It combines the functionality of both INSERT and UPDATE queries.
It allows you to insert new records into a table or update existing ones based on a specified condition. This query is particularly useful when synchronizing data between different sources or tables.
Understanding the different types of queries that change data in a database is essential for effective database management. The INSERT, UPDATE, DELETE, and MERGE queries each serve specific purposes and should be used with care to ensure data integrity.
By familiarizing yourself with these types of queries, you will have the necessary tools to manipulate and manage data effectively in your applications.