Archive for the 'SQL' Category

Surrogate Key In Database Design

Discuss the concept of surrogate key in database design, from what it is to when to use it.

Composite Key In SQL

Discusses the concept of composite key in SQL, and shows examples of creating a composite key in MySQL, Oracle, and SQL Server.

Rename Table in SQL

Shows the syntax to rename a table in MySQL, Oracle, and SQL Server.

Find 2nd Largest Value Using SQL

Shows how to find the 2nd largest number in SQL across different database systems.

Find Duplicates in SQL

Find out how to use SQL to find duplicates in a table. In addition, learn how to retrieve all records that contain duplicates.

Copy a table in SQL

Describes how to copy a table in a relational database using SQL. You can either copy just the table structure, or the table structure and the data.