SQL wiithout entities???

Question

Hi,
I'm curious how people are doing SQL statements that return data from from several tables. Are the relationships (parent/child) set up in the entities and all the data gets return? For example we have apps where users can query data by entering there query data in a form. An sql statement is built from the data entered and the results returned to them. If the query performed is large isn't this an issue?
I was looking at an example from hibernate:
Iterator results = em.createQuery(
"select cat.color, min(cat.birthdate), count(cat) from Cat cat " +
"group by cat.color")
.getResultList()
.iterator();
while ( results.hasNext() ) {
Object[] row = results.next();
Color type = (Color) row[0];
Date oldest = (Date) row[1];
Integer count = (Integer) row[2];
This actually didn't work. It's like row is meant to be field?
I've also seen examples where people create a dummy entity and pass that into the SQL statement. however that also didn't work.
Which is the best way?
thanks
David

Answer 1

Hi Tom,
The reason for different behaviour in Try Catch block is as mentioned below from -
http://msdn.microsoft.com/en-us/library/ms175976.aspx
The following types of errors are not handled by a CATCH block when they occur at the same level of execution as the TRY…CATCH construct:
Errors that occur during statement-level recompilation, such as object name resolution errors that occur after compilation because of deferred name resolution.
The following example shows how an object name resolution error generated by a
SELECT statement is not caught by the
TRY…CATCH construct, but is caught by the CATCH block when the same
SELECT statement is executed inside a stored procedure.
USE AdventureWorks2012;
GO
BEGIN TRY
-- Table does not exist; object name resolution
-- error not caught.
SELECT * FROM NonexistentTable;
END TRY
BEGIN CATCH
SELECT
ERROR_NUMBER() AS ErrorNumber
,ERROR_MESSAGE() AS ErrorMessage;
END CATCH
The error is not caught and control passes out of the TRY…CATCH construct to the next higher level.
Running the SELECT statement inside a stored procedure will cause the error to occur at a level lower than the
TRY block. The error will be handled by the
TRY…CATCH construct.
-- Verify that the stored procedure does not exist.
IF OBJECT_ID ( N'usp_ExampleProc', N'P' ) IS NOT NULL
DROP PROCEDURE usp_ExampleProc;
GO
-- Create a stored procedure that will cause an
-- object resolution error.
CREATE PROCEDURE usp_ExampleProc
AS
SELECT * FROM NonexistentTable;
GO
BEGIN TRY
EXECUTE usp_ExampleProc;
END TRY
BEGIN CATCH
SELECT
ERROR_NUMBER() AS ErrorNumber
,ERROR_MESSAGE() AS ErrorMessage;
END CATCH;
For other details on SQL Server Object dependencies -
http://sathyadb.blogspot.in/2012/08/sql-server-object-dependencies.html
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