For my SQL queries, I usually do the following for SELECT statements:
SELECT ...
FROM table t
WHERE 1=1
AND t.[column1] = @param1
AND t.[column2] = @param2
This will make it easy if I need to add / remove / comment any WHERE clauses, since I don't have to care about the first line.
Is there any performance hit when using this pattern?
Additional Info:
Example for sheepsimulator and all other who didn't get the usage.
Suppose the above query, I need to change @param1 to be not included into the query:
With 1=1:
...
WHERE 1=1 <-- no change
--AND t.[column1] = @param1 <-- changed
AND t.[column2] = @param2 <-- no change
...
Without 1=1:
...
WHERE <-- no change
--t.[column1] = @param1 <-- changed
{AND removed} t.[column2] = @param2 <-- changed
...