Is there an elegant way to Invert a Bit value in an SQL insert Statement?
I'm converting some data in SQL Server:
开发者_如何学PythonINSERT INTO MYTABLE (AllowEdit)
(Select PreventEdit from SOURCETABLE)
so I need to inverse the bit value from source table. I expected NOT
to work, as this is how I would do it in code, but it doesn't. The most elegant way I can think of is:
INSERT INTO MYTABLE (AllowEdit)
(Select ABS(PreventEdit -1) from SOURCETABLE)
Is there a more standard way to do it?
I did not test this myself, but you should be able to use the bitwise negation operator, ~
on a bit:
INSERT INTO MYTABLE (AllowEdit)
(SELECT ~PreventEdit FROM SourceTable)
NOT or XOR if bit
SELECT ~PreventEdit FROM SourceTable
SELECT 1 ^ PreventEdit FROM SourceTable
If it isn't actually bit in SourceTable then this:
SELECT 1 - PreventEdit FROM SourceTable
Edit: A test, note NOT is 2s complement so could give odd results if not used on a bit column
DECLARE @bitvalue bit = 1, @intvalue int = 1;
SELECT ~@bitvalue, ~@intvalue
SELECT 1 ^ @bitvalue, 1 ^ @intvalue
SELECT 1 - @bitvalue, 1 - @intvalue
SELECT @bitvalue = 0, @intvalue = 0
SELECT ~@bitvalue, ~@intvalue
SELECT 1 ^ @bitvalue, 1 ^ @intvalue
SELECT 1 - @bitvalue, 1 - @intvalue
INSERT INTO MYTABLE (AllowEdit) (SELECT ~ISNULL(PreventEdit,0) FROM SourceTable)
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