Why would someone use `WHERE 1=1 AND <conditions>` in a SQL clause (Either SQL obtained through concatenated strings, either view definition)

I've seen somewhere that this would be used to protect against SQL Injection, but it seems very weird.

If there is injection `WHERE 1 = 1 AND injected OR 1=1` would have the same result as `injected OR 1=1`.

Later edit: What about the usage in a view definition?

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Thank you for your answers.

Still,
I don't understand why would someone use this construction for defining a view, or use it inside a stored procedure.

Take this for example:

```
CREATE VIEW vTest AS
SELECT FROM Table WHERE 1=1 AND table.Field=Value

```