On 29.03.2011 15:17, Max Vlasov wrote:
> Thanks, this forced me to search more on the topic. I use Delphi and it
> appears that all Borland compilers has their own floating-point exception
> handling chain and it is on by default so if any division by zero or
> overflow appears inside sqlite3_step Delphi will handle this with its own
> exception handling.
When running SQLite from Delphi, you must disable FPU exceptions. Below
is a simple console project which uses the DISQLite3 Delphi port of
SQLite to demonstrate how this works.
Ralf
---
{ DISQLite3 example project to show how to disable FPU exceptions so
that very large integer numbers are correctly converted to 'Inf' text.
Exceptions should always be disabled before running any C library from
Delphi. This is important because exceptions do not exist in C and C
does not know how to handle them. Exceptions will therefore cause the
entire C library stack to unwind undisturbed until the exception is
finally handled by Delphi code. The result of this is undefined and
might range from simple memory leaks to more severe and complicated
problems.
This applies to all C libraries, both internal (*.obj) and extenal
(*.dll).
Visit the DISQLite3 Internet site for latest information and updates:
http://www.yunqa.de/delphi/
Copyright (c) 2011 Ralf Junker, Delphi Inspiration <del...@yunqa.de>
--------------------------------------------------------------------- }
program DISQLite3_Very_Large_Integer;
{$APPTYPE CONSOLE}
{$I DI.inc}
{$I DISQLite3.inc}
uses
{$IFDEF FastMM}FastMM4, {$ENDIF}DISystemCompat, SysUtils,
DISQLite3Api;
var
DB: sqlite3_ptr;
procedure ExecSql(const SQL: Utf8String);
var
i: Integer;
Stmt: sqlite3_stmt_ptr;
begin
sqlite3_check(sqlite3_prepare_v2(DB,
PUtf8Char(SQL), Length(SQL), @Stmt, nil), DB);
try
while sqlite3_check(sqlite3_step(Stmt), DB) = SQLITE_ROW do
begin
for i := 0 to sqlite3_column_count(Stmt) - 1 do
begin
if i > 0 then Write(', ');
Write(sqlite3_column_str(Stmt, i));
end;
WriteLn;
end;
finally
sqlite3_finalize(Stmt);
end;
end;
const
DB_FILE_NAME = 'test.db3';
begin
{ Disable FPU exceptions. No need to restore, setting is process
specific. }
Set8087CW($133F);
try
sqlite3_initialize;
DeleteFile(DB_FILE_NAME);
sqlite3_check(sqlite3_open(DB_FILE_NAME, @DB));
try
ExecSql('CREATE TABLE t1(v TEXT);');
ExecSql('INSERT INTO t1 VALUES(''' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'1234567890'');');
ExecSql('INSERT INTO t1 VALUES(''-' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'123456789012345678901234567890123456789012345678901234567890' +
'1234567890'');');
ExecSql('SELECT length(v), CAST(v AS float) FROM t1;');
finally
sqlite3_check(sqlite3_close(DB), DB);
sqlite3_shutdown;
end;
except
on e: Exception do
WriteLn(e.Message);
end;
WriteLn;
WriteLn('Done - Press ENTER to Exit');
ReadLn;
end.
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