how to write an if condition case in stored procedure

i have an table where i am passing 5 paramter

table name=" image"
parameter
@imageID,
@imageName,
@imageDirectory,
@imageResource,

from the front end [from page that is from textbox control] if they didnot send any values to stored procedue then i should do an simple Query condition1:

 select  * From image

condition 2: if they send any value to these above parameter then collect those vlaues and retrive result based on the parameted sent

condition 3: here they might send values to any of the of the parameter in that condition select values for that parameter . for the parameter which they have not send values we can 开发者_开发百科send 'null' or ' '

so based on that retrive the result

so how write an Stored procedure for such an condition. handling all the three condition

anyhelp would be really great thank you

Try something along these lines:

SELECT * FROM IMAGE i
WHERE 1=1 
AND (@ImageID IS NULL OR i.ImageId = @ImageID )
AND (@ImageName IS NULL OR i.ImageName = @ImageName )
AND (@ImageDirectory IS NULL OR i.ImageDirectory = @ImageDirectory)
AND (@ImageResource IS NULL OR i.ImageResource = @ImageResource)

You can also use the IsNull(transact-SQL specific) or Coalesce (SQL-92 standard) function, as in:

 Select * From Table
 Where imageId = Coalesce(@ImageId, imageId)
    And imageName = Coalesce(@imageName,imageName)
    etc.