Problem with ODBC and clob data
lazarus / 16-Databases

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MircoN · 2007-10-16 12:12

My system is Linux (SUSE 10.1) and i try to retrive data from IBM DB2
database with ODBC connection (unixODBC).
I use TODBCconnecion and TSQLQuery. All the system work fine for all
kind of data (i.e. blob), but with the clob data the result of query
is incorrect, like:

"⃈…„?@ÅÕåññðð@`@Á™£‰ƒ–“–z@ôõñ ...."

I use for blob and clob:

"if self.SQLQuery1.Fields.Fields.IsBlob then
begin
.       BlobField:=TBlobField(self.SQLQuery1.Fields.Fields);
.      if not(BlobField.IsNull) then  Result:=fb.Value; "
end;

Where is the (my) error?
Can you help me?

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MircoN · 2007-10-22 12:50

I have discovered the problem. There is not error: the problem born
when the clob data is inserted on database by "AsString" way.
If the clob data is inserted by "AsBlob" way all work fine.
I can't modify the method that write tha clob data on database and so
for me is necessary read the clob data in other way.
I have modified the function TODBCConnection.LoadField: I have
introduced a castom way for manage the
FieldDef.DataType=ftMemo
(the source code is the same for ftBlob but I have used            
SQL_C_CHAR             and                
 BlobBufferSize:=StrLenOrInd+1)