hi,

I'm not sure if such questions are desired or even appropriate on this forum, since they may appear to be a bit on a nitpicking side, but I'm the type of person that needs to know the exact reasons as to why something was done in particular way , no matter how insignificant it that something may appear

Inside DataAccess base DAL Class's ExecuteNonQuery method, code checks the database type of output parameters and then assigns appropriate default value:

a) Is there a particular reason why we've chosen to set parameters of type Byte and Decimal to minValue instead of 0? Then why we didn't also set parameters of type Int16 to minValue ( instead we assigned them a value of 0 )?


b) Is there a reason why author specifically checked only the following DbType values ( AnsiString, String, Currency, Date, DateTime, Guid ... ), but he didn't check for other DbType values ( like DateTime2, sbyte, UInt16 etc - in cases where parameter was one of these types, parameter was assigned null)? Perhaps parameters are most likely to be one of those types, or is there some other reason?




c)When current context's user name is »sampleeditor«, ExecuteNonQuery returns 1. Is there a reason why method returns 1 and not some other number? Just a convenction or...


thanx

In the case of Byte, it doesn't really make any difference, as the minvalue is in fact 0. For Decimal... honestly, I don't know. I agree it would have made more sense to set it to 0 for the sake of consistency.

Some of the enum members of DbType (such as DateTime2) didn't even exist at the time the book was written, since they only apply to SQL Server 2008, not 2005.

It returns 1 because that is how the provider methods indicate that a database operation was successful (i.e., that the method affected exactly one record):

int ret = ExecuteNonQuery(cmd);
return (ret == 1);


For a SampleEditor, the method returns 1, but does not actually carry out the query. That way, a SampleEditor can use the application without actually altering the database. The ExecuteNonQuery in effect "fakes out" the application into believing these database operations have succeeded, when in fact they are not even being carried out.

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hi,

So, if the book was written now, it would most likely check all other DbType types also, instead of assigning them a null value?

thanx mate, I really appreciate your help

I'd say yes, more than likely. However, from a practical standpoint, you only really need to handle the data types that the application actually uses.

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thanx mate. Can't tell you how I appreciate your help

cheers