How to Simulate SQL Server's IF NOT EXISTS in SQLite for Conditional Inserts?

Inserting Records in SQLite When They Don't Exist: Exploring IF NOT EXISTS

In MS SQL Server, the IF NOT EXISTS clause is used to conditionally insert a record into a table. For example, the following code snippet creates a new record in the EVENTTYPE table if it doesn't already exist:

IF NOT EXISTS(SELECT 1 FROM EVENTTYPE WHERE EventTypeName = 'ANI Received') 
    INSERT INTO EVENTTYPE (EventTypeName) VALUES ('ANI Received');

However, SQLite doesn't natively support the IF NOT EXISTS clause. As a result, developers seeking to port this functionality to SQLite may encounter challenges.

SQLite Workarounds for Conditional Inserts

Despite the lack of direct IF NOT EXISTS support, there are several workarounds available in SQLite. One common approach is to use the INSERT OR IGNORE statement:

INSERT OR IGNORE INTO EVENTTYPE (EventTypeName) VALUES 'ANI Received'

This statement attempts to insert a record into the EVENTTYPE table, but it doesn't raise an error if the record already exists.

Alternatively, you can use a combination of SELECT and INSERT statements, as seen below:

INSERT INTO EVENTTYPE (EventTypeName)
SELECT 'ANI Received'
WHERE NOT EXISTS (SELECT 1 FROM EVENTTYPE WHERE EventTypeName = 'ANI Received');

This code first checks whether the record already exists using a SELECT statement. If it doesn't exist, the INSERT statement is executed to add the new record.

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