asked on
Visual Studio Query
I have a Visual Studio Form Called Form1
It is conencted to the Query_BuilderDataSet1 which retrive data from a Table tbl_Resources
On the Form1 i have the Grid from the Data set with contains the collumn ID_Resource , Name , Region, Town , Employer
From the Table adpter tbl_ResourceTableAdpter i have Open the Query Bulder and design a Query : SELECT ID_Resources , Name , Region , Town , Employer
FROM tbl_Resources
WHERE (Region=@Region OR @Region IS NULL ) AND (Emplyer =@Employer OR @Employer IS NULL )
For example i have inserted IS NULL thinking to have the possibility to Optionally insert only one of the 2 Parameters
But it is Not Working ,
When i Go on the Form1 and Fill only one of the 2 Text Box created by the VS designer
the Return into the Grid on Form1 is an Empty Grid
Any one that can help to write the SQL code or the Visual Basic code behing the Form1 to handle the Opition to have declared only 1 of the 2 Crtieria
For Clarity i have also u Button that on Click will remove the Query and will show again all the records
Thanks fro Help
It is conencted to the Query_BuilderDataSet1 which retrive data from a Table tbl_Resources
On the Form1 i have the Grid from the Data set with contains the collumn ID_Resource , Name , Region, Town , Employer
From the Table adpter tbl_ResourceTableAdpter i have Open the Query Bulder and design a Query : SELECT ID_Resources , Name , Region , Town , Employer
FROM tbl_Resources
WHERE (Region=@Region OR @Region IS NULL ) AND (Emplyer =@Employer OR @Employer IS NULL )
For example i have inserted IS NULL thinking to have the possibility to Optionally insert only one of the 2 Parameters
But it is Not Working ,
When i Go on the Form1 and Fill only one of the 2 Text Box created by the VS designer
the Return into the Grid on Form1 is an Empty Grid
Any one that can help to write the SQL code or the Visual Basic code behing the Form1 to handle the Opition to have declared only 1 of the 2 Crtieria
For Clarity i have also u Button that on Click will remove the Query and will show again all the records
Thanks fro Help
System ProgrammingMicrosoft DevelopmentVisual Basic.NET
Last Comment
sanlorenzo
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ASKER
Yes thanks , this is a Typing Mistake , done while i typed the question
the SQL on the Application is correct
the SQL on the Application is correct
ASKER
Ok , i see SQL is not correct IS NULL is not the best when i have to deal with Empty String
so what do you suggest as a solution ?? Thanks
so what do you suggest as a solution ?? Thanks
Ermm. Why did you accept the comment from the other expert despite you saying it isn't correct AND pointing out my comment was relevant (correct)?
ASKER
don't yiou think that some can do a mistake ??/ you may send agoin the answer , obviousily i will accept
Repeat of earlier comment:
Have you checked the parameters you actually pass in ?
The empty string "" is not the same as the value NULL
And to check for an empty string a simple modification is required
(Region=@Region OR @Region IS NULL )
should be
((Region=@Region) OR (@Region IS NULL) OR (@Region=''))
where the '' are two single quote marks (it might require double quotes, some SQL can be fussy) and similarly for any other checks in the where clause.
ps. I like using lots of brackets, it might not be necessary but it makes it much easier to read the logic.
pps. I really do mean check what your parameter values are, if you are really passing null into the query then this comment is also not the solution to your problem.
Have you checked the parameters you actually pass in ?
The empty string "" is not the same as the value NULL
And to check for an empty string a simple modification is required
(Region=@Region OR @Region IS NULL )
should be
((Region=@Region) OR (@Region IS NULL) OR (@Region=''))
where the '' are two single quote marks (it might require double quotes, some SQL can be fussy) and similarly for any other checks in the where clause.
ps. I like using lots of brackets, it might not be necessary but it makes it much easier to read the logic.
pps. I really do mean check what your parameter values are, if you are really passing null into the query then this comment is also not the solution to your problem.
ASKER
Thanks Mr South
sorry , i did not accept my self , have good day
sorry , i did not accept my self , have good day
it should read
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