How Can I Insert Unique Values into a Table Using 'INSERT VALUES WHERE NOT EXISTS'?

Inserting Unique Values with "INSERT VALUES WHERE NOT EXISTS"

Enhancing data integrity is crucial in data entry applications. To prevent duplicate entries in a data table, inserting unique values is essential. This can be achieved using the "INSERT VALUES WHERE NOT EXISTS" syntax.

Understanding the Issue

The goal is to insert data into a table while ensuring that the combination of values in specific columns (e.g., SoftwareName and SoftwareSystemType) is unique. If an insert query tries to insert duplicate values, an error should be thrown, and the data should not be entered.

Incorrect Syntax

The original syntax attempting to use "INSERT VALUES WHERE NOT EXISTS" is flawed. It attempts to "SELECT" data from the table and insert it if it does not exist, which is not the intended functionality for an insert operation.

Improved Solution Using IF-BEGIN Block

To implement the desired functionality, one can employ an IF-BEGIN block:

IF NOT EXISTS 
(   SELECT  1

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