What is a Primary Key in SQL Databases?

MS SQL primary key

The primary key (or keyword) is used to identify each row in a relational database table. It ensures that the tables do not contain duplicate records.
The primary key consists of one or more columns that contain unique values.

The CHARINDEX function in SQL

SQL CHARINDEX table

The SQL CHARINDEX function is used to return the position of the specified substring in a string. For example, finding the position of ‘@’ in an email address:

SQL UPDATE Command

An infographic guide to updating records in relational databases, featuring syntax insights, conditional updates, and best practices for efficient data management.

This UPDATE command will update whole data in the specified column by new value. For limiting the changes only to the specific records, we use UPDATE with the WHERE clause.

SQL LIKE Operator

A visual graphic shows what is SQL LIKE operator. It also shows important points about the LIKE along with example queries with percentage and underscore wildcards.

The SQL LIKE operator enables us searching a column by specified pattern. The LIKE uses two wildcards for performing search: (% & _)

CREATE TABLE Statement in SQL

SQL CREATE TABLE

The CREATE TABLE command is used to create new table in the Relational databases. This tutorial explains how to create new table, copy table from another table..

SQL SELECT Statement

An infographic guide to mastering data retrieval with SELECT statements, filtering, sorting, grouping and more.

The data is stored in the tables in relational database management systems. In order to retrieve data from tables, we use SQL SELECT statement.