sql工厂类

//author: cxg
//sql工厂

unit MySQL;

interface

uses
  SysUtils, SqlExpr, DBClient, db, DBXCommon,Provider;

type
  TMySQL = class(TObject)
  private
    fSqlcommand: string;
    fQry: TClientDataSet;
    fSqlMethod: TSqlServerMethod;
    fSqlConnection: TSQLConnection;
    fDbxTrans: TDBXTransaction;
    fP:TDataSetProvider;
    fD:TClientDataSet;
    procedure SetConnection(Cn:TSQLConnection);
  public
    constructor Create;
    destructor Destroy; override;
    procedure AddParam(const Value: Variant);
    //说明: 添加参数值
    //参数: const aValue: Variant -- 参数值
    function GetData: TDataSet;  //非事务性查询
    procedure ExecSql;              //事务性操作
    procedure BeginTrans;          //开始事务
    procedure CommitTrans;         //提交事务
    procedure RollbackTrans;       //回滚事务
    property CommandText: string read fSqlcommand write fSqlcommand;  //sql语句
    property Connection: TSQLConnection read fSqlConnection write SetConnection; //连接控件
  end;

implementation

{ TMySQL }

procedure TMySQL.AddParam(const Value: Variant);
begin
  fQry.Params.AddParameter.Value :=Value;
end;

procedure TMySQL.BeginTrans;
begin
  fDbxTrans :=fSqlConnection.BeginTransaction;
end;

procedure TMySQL.CommitTrans;
begin
  fSqlConnection.CommitFreeAndNil(fDbxTrans);
end;

constructor TMySQL.Create;
begin
  inherited;
  fQry := TClientDataSet.Create(nil);
  fSqlMethod :=TSqlServerMethod.Create(nil);
  fp:=TDataSetProvider.Create(nil);
  fP.Name :='p23424';
  fd:=TClientDataSet.Create(nil);
  fD.ProviderName :=fp.Name;
end;

destructor TMySQL.Destroy;
begin
  fQry.Free;
  fQry :=nil;
  fP.Free;
  fp:=nil;
  fD.Free;
  fd:=nil;
  fSqlMethod.Free;
  fSqlMethod :=nil;
  inherited;
end;

procedure TMySQL.ExecSql;
begin
  fSqlMethod.ServerMethodName := 'TServerMethods1.PostData';
  fSqlMethod.ParamByName('sql').AsString := fSqlcommand;
  fSqlMethod.ParamByName('params').AsParams := fQry.Params;
  fSqlMethod.ExecuteMethod;
end;

function TMySQL.GetData: TDataSet;
begin
  fSqlMethod.ServerMethodName := 'TServerMethods1.getData';
  fSqlMethod.ParamByName('sql').AsString := fSqlcommand;
  fSqlMethod.ParamByName('params').AsParams := fQry.Params;
  fSqlMethod.ExecuteMethod;
  Result := fSqlMethod.ParamByName('returnparameter').AsDataSet;
end;

procedure TMySQL.RollbackTrans;
begin
  fSqlConnection.RollbackFreeAndNil(fDbxTrans);
end;

procedure TMySQL.SetConnection(Cn: TSQLConnection);
begin
  if (fSqlMethod.SQLConnection =nil) then
  fSqlMethod.SQLConnection := Cn;
end;

end.