What does =+ mean in (T)SQL?

Question

I found something like this in a SqlServer DB stored proc:

SELECT stuff
  FROM mytable
 WHERE mytable.column = + @parameter

It seems to run without error, so I assume it's okay. What would the "+" be doing?

(Not surprisingly, this is a difficult topic to effectively search on, so I apologize in advance if this is a duplicate.)

Answer 1

+ is the opposite of - which changes sign.

It does nothing.

Answer 2

What type is @parameter? This probably just a unary plus, (as opposed to minus). For numeric types this has no effect.

Answer 3

It looks like it is a short hand notation for converting the parameter into a numeric type. Depending on your database server, it might not even be needed.

Answer 4

Returns the data type of numeric_expression, except that an unsigned tinyint expression is promoted to a smallint result.

Positive unary operator

Answer 5

Unary + doesn't do anything in T-SQL.

Perhaps the person who wrote it saw 0+@parameter and deleted the 0 to "optimize it". 0+@parameter generates an error if @parameter isn't numeric, whereas unary + doesn't do anything.