What does =+ mean in (T)SQL?

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

SELECT stuff
  FROM mytable
 WHERE mytable.column = + @开发者_StackOverflow社区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.)

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+ is the opposite of - which changes sign.

It does nothing.

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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.

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

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

Positive unary operator

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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.