Oui je sais travailler sans problème avec MySql et Delphi.
Il est important de choisir le bonne dll pour libmysql.dll
et dbexpmysql.dll (voir site borland).
exemple de source:
unit MyDBCon;
interface
uses
SysUtils, Classes, DBXpress, DB, SqlExpr, FMTBcd,Functions, Provider,
DBClient, DBLocal, DBLocalS;
type
TDMMyUsOptions = class(TDataModule)
MySQLCon: TSQLConnection;
MyClientDataSet: TSQLClientDataSet;
SqlDataSetUpd: TSQLDataSet;
procedure DataModuleCreate(Sender: TObject);
private
procedure ReadInitFile(sFilename:string;sSubCateg:string;ObjCon:TSQLConnection);
{ Private declarations }
public
{ Public declarations }
procedure Connect(sFile:String;sGroup:String);
procedure Close();
function GetDataset(sSql:string):TSQLClientDataSet;
procedure GetLocDataSet(sSql:string;ClientDataSet:TSQLClientDataSet);
function UpdateDataSet (sSql:Ansistring):integer;
function LocateDataset (sTable:string;sField:string;sValue:string):Boolean;
end;
var
DMMyUsOptions: TDMMyUsOptions;
implementation
{$R *.dfm}
function TDMMyUsOptions.LocateDataset(sTable:string;sField:string;sValue:string):Boolean;
var
sSqlString:string;
begin
result := false;
//SQLDataSetUpd.DBConnection :=MySQLCon;
SQLDataSetUpd.CommandType :=ctQuery;
sSqlString:= 'select ' + sfield +' from '+ sTable + ' where ' + sField + ' = ' + ''''+ sValue+ '''';
SQLDataSetUpd.CommandText := sSqlString;
SQLDataSetUpd.Open;
if SQLDataSetUpd.Active = true then
begin
if SQLDataSetUpd.RecordCount > 0 then
result := true;
SQLDataSetUpd.Close;
end;
end;
procedure TDMMyUsOptions.ReadInitFile(sFilename:string;sSubCateg:string;ObjCon:TSQLConnection);
var
F:textfile;
lig:String;
bFlag:boolean;
iPos:Integer;
begin
bflag:=false;
if (sFileName <> '')and (sSubCateg <> '') then
begin
sSubCateg := '[' + sSubCateg + ']';
assignfile(F,sFileName);
reset(F);
while (not eof(F))and (bflag=false) do
begin
readln(F,lig);
if InStr(0,lig,sSubCateg) = 1 then
begin
while bflag=false do
begin
readln(F,lig);
if InStr(0,lig,'User_Name')=1 then
begin
iPos:=Instr(0,lig,'=');
if iPos > 1 then
begin
iPos:=length(lig)-ipos;
ObjCon.Params.Values['User_Name']:=right(lig,ipos);
end;
end;
if InStr(0,lig,'Password')=1 then
begin
iPos:=Instr(0,lig,'=');
if iPos > 1 then
begin
iPos:=length(lig)-ipos;
ObjCon.Params.Values['Password']:=right(lig,ipos);
end;
end;
if InStr(0,lig,'Database')=1 then
begin
iPos:=Instr(0,lig,'=');
if iPos > 1 then
begin
iPos:=length(lig)-ipos;
ObjCon.Params.Values['Database']:=right(lig,ipos);
end;
end;
if InStr(0,lig,'HostName')=1 then
begin
iPos:=Instr(0,lig,'=');
if iPos > 1 then
begin
iPos:=length(lig)-ipos;
ObjCon.Params.Values['HostName'] :=right(lig,ipos);
end;
end;
if InStr(0,lig,'[END]')=1 then
begin
bflag:=True;
end;
end;
end;
end;
closefile(f);
end;
end;
function TDMMyUsOptions.GetDataset (sSql:string):TSQLClientDataSet;
begin
MyClientDataSet.DBConnection :=MySQLCon;
MyClientDataSet.CommandType :=ctQuery;
MyClientDataSet.CommandText :=sSql;
MyClientDataSet.Open;
result :=MyClientDataSet;
end;
procedure TDMMyUsOptions.GetLocDataSet(sSql:string;ClientDataSet:TSQLClientDataSet);
begin
if ClientDataSet.Active=True then
begin
ClientDataSet.Close;
end;
ClientDataSet.DBConnection :=MySQLCon;
ClientDataSet.CommandType :=ctQuery;
ClientDataSet.CommandText :=sSql;
ClientDataSet.Open;
end;
function TDMMyUsOptions.UpdateDataSet(sSql:Ansistring):integer;
begin
try
SQLDataSetUpd.CommandText :=sSql;
result := SQLDataSetUpd.ExecSQL;
except
result := -1;
end;
end;
procedure TDMMyUsOptions.Connect(sFile:String;sGroup:String);
begin
ReadInitFile(sFile,sGroup,MySQLcon);
//ReadInitFile('MyUsOptions.txt','MyUsOptions',MySQLcon);
MySQLcon.Open;
end;
procedure TDMMyUsOptions.Close;
begin
if MySQLcon.Connected = true then
begin
MySQLcon.Close;
MySQLcon.Free;
end;
end;
procedure TDMMyUsOptions.DataModuleCreate(Sender: TObject);
begin
SQLDataSetUpd.SQLConnection :=MySQLCon;
SQLDataSetUpd.CommandType :=ctQuery;
end;
end.
-------------------------------
Réponse au message :
-------------------------------
> lorsque j'execute :
> MySQLDataSet.CommandType :=ctQuery;
> MySQLDataSet.CommandText :='select Symbol From Tb2';
> MySQLDataSet.Open;
>
> Si Symbol est définit comme index ou clé primaire (et seulement dans ce cas la). J'ai l'erreur suivante :
> Invalid variant type conversion.
> Comment solutionner cette erreur.....
> Merci +++
> Eric
>
>
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