What is the difference between CREATE INDEX AND CREATE UNIQUE INDEX?

android, sqlite

Solution

`CREATE UNIQUE INDEX` isn't just an index : it adds the constraint that all records must have a different value for this column or combination of columns. If you try to insert a record whit the same combination, an error will be raised and prevent the insert (or update).

Use UNIQUE as soon as you're sure you'll have at most one record for some kind of key (user name for example).

EDIT : Here's a link to the documentation of CREATE INDEX, it describes in detail the syntax.

Problem

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