SQL: What does NULL as ColumnName imply

column-alias, sql

Solution

Aliasing can be used in a number of ways, not just to shorten a long column name.

In this case, your example means you're returning a column that always contains `NULL`, and it's alias/column name is `aColumn`.

Aliasing can also be used when you're using computed values, such as `Column1 + Column2 AS Column3`.

Problem

I understand that `AS` is used to create an alias. Therefore, it makes sense to have one long name aliased as a shorter one. However, I am seeing a `SQL` query `NULL as ColumnName` What does this imply? ``` SELECT *, NULL as aColumn ```

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