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Bahamut · Guest

Hi, All

I'm using Delphi 6 Enterprise + MSSQLServer2000 on Win2K.
I use TADOCommand to update data with a parameterized sql statement like:

update Table1
set Field1 = :F1
where KeyField = :KeyField

and the command will be executed more than once using the different
parameter values:

while <expression> do
begin
Command.Parameters.ParamValues['F1'] := <ValueWillBeChangedEveryLoop>
Command.Parameters.ParamValues['KeyField'] :=
<ValueWillBeChangedEveryLoop>
Command.Execute;
end;

DelphiHelp say "the performance is enhanced if the query is prepared before
execution, particularly if it is a parameterized query that is executed more
than once using the same parameter values"......
How does the Prepared property of TADODataset and TADOCommand work in this
instance? (execute more than once using the different parameter values)

Can I set Prepared property to True before the Loop?
or set Prepare to True and set to False after Execute in each loop ?

Bahamut

Mike Collier · Guest

Bahamut · Guest

Thanks for your reply!

I also read an article about Prepared in ADO from MSDN:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvbdev00/html/vb00j1.asp
It's the same to the viewpoint of you, but I want to know the operation
principle of Prepared in Delphi ADO components...

Does it compile a parameterized SQL "with the value of parameter" to a
temporary stored procedures?
If I change the value of parameter(not change the SQL statement), does it
need to re-prepare the SQL?

Bahamut

"Mike Collier" <noEmail@noEmail> ?¤J?¥ó
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