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[solved] PostgreSQL WideMemo field
Posted: 15.10.2013, 17:18
by markus
Hi,
I've recently updated my Zeos source code from svn, and i've stumbled upon such problem:
When using AsString method of TField on text column from DB i get Access Violation when value in column is empty string.
If it's NULL or column have actual value then it works ok.
This error occurs first in rev. 2746.
Best regards,
Marek
Re: PostgreSQL WideMemo field
Posted: 16.10.2013, 20:35
by EgonHugeist
Hi Marek,
I made a testcase to reproduce your report:
Code: Select all
procedure TZGenericTestDbcResultSetMBCs.TestClobEmptyString;
var
Query: TZQuery;
TextLob: String;
begin
Query := CreateQuery;
try
with Query do
begin
SQL.Text := 'DELETE FROM blob_values where b_id = '+ IntToStr(TEST_ROW_ID-2);
ExecSQL;
if StartsWith(LowerCase(Connection.Protocol), 'oracle') then
TextLob := 'b_clob'
else if StartsWith(LowerCase(Connection.Protocol), 'sqlite') then
TextLob := 'b_text'
else
TextLob := 'b_text';
Sql.Text := 'INSERT INTO blob_values (b_id,'+TextLob+')'
+ ' VALUES (:b_id,:b_text)';
CheckEquals(2, Params.Count);
Params[0].DataType := ftInteger;
{$IFDEF WITH_WIDEMEMO}
if Connection.DbcConnection.GetConSettings.CPType = cCP_UTF16 then
Params[1].DataType := ftWideMemo
else
{$ENDIF}
Params[1].DataType := ftMemo;
Params[0].AsInteger := TEST_ROW_ID-2;
{$IFDEF WITH_WIDEMEMO}
if Connection.DbcConnection.GetConSettings.CPType = cCP_UTF16 then
Params[1].AsWideString := ''
else
{$ENDIF}
Params[1].AsString := '';
ExecSQL;
CheckEquals(1, RowsAffected);
SQL.Text := 'SELECT * FROM blob_values where b_id = '+ IntToStr(TEST_ROW_ID-2);
CheckEquals(0, Query.Params.Count);
Open;
CheckEquals(1, RecordCount);
CheckEquals(False, IsEmpty);
CheckEquals(TEST_ROW_ID-2, FieldByName('b_id').AsInteger);
CheckEquals(False, FieldByName(TextLob).IsNull, 'Memo is not empty.');
CheckEquals('', FieldByName(TextLob).AsString, 'Empty but not null String');
Close;
SQL.Text := 'DELETE FROM blob_values where b_id = '+ IntToStr(TEST_ROW_ID-1);
ExecSQL;
end;
finally
Query.Free;
end;
end;
But i can't see the AV your are talking about. Can you have a look and tell me what i have to change to catch the bug?
EDIT: Found a possible index overflow for empty strings and fixed this by switching to pointers. R2839 \testing-7.2
Re: PostgreSQL WideMemo field
Posted: 18.10.2013, 21:52
by markus
Hi Michael,
Sorry for late reply, i've downloaded latest rev from svn and i don't have this error anymore.
Thanks a lot for your support.
Best regards,
Marek