• 一个方便有用的Delphi数据库操作类(转)


    //
    //在长时间的开发工作中,慢慢做了一些类库,下面这个是一个数据库操作类,欢迎大家交流
    //联系方式    QQ:413133880         Email: QQ413133880@gmail.com
    unit MyADO;

    interface

    uses
    SysUtils, Classes,ADODB,DB,Variants,StdCtrls,Dialogs;

    type
    TMyADO = class(TComponent)
        private
        Connection: TADOConnection;
        Query: TADOQuery;
        Table: TADOTable;
        FConnectionString:string;
        procedure InitQuery(InputQuery: TADOQuery; QueryString: String);
        function CheckParaEqual(QueryString: String; ParameterList: TStringList):Boolean;
        procedure InitParameter(InputQuery:TADOQuery;QueryString:string;ParameterList:TStringList);
    public
        constructor Create(ConnectionString: String);virtual;
        destructor Destory;virtual;
        procedure SetConnectionString(ConnectionString: string);
        function GetConnection():TADOConnection;overload;virtual;
        function GetConnection(ConnectionString: String): TADOConnection;overload;virtual;
        function GetQuery: TADOQuery;overload;virtual;
        procedure GetQuery(InputQuery: TADOQuery; QueryString: String);overload;virtual;
        procedure GetQuery(InputQuery:TADOQuery; QueryString: String; ParameterList: TStringList);overload;virtual;
        function GetTable: TADOTable;overload;virtual;
        function GetTable(TableName: String): TADOTable;overload;virtual;
        function GetTable(TableName: String; Connection: TADOConnection):TADOTable;overload;virtual;
        function GetExecuteScalar(QueryString: String): Variant;overload;virtual;
        function GetExecuteScalar(QueryString: String; ParameterList: TStringList): Variant;overload;virtual;
        function GetExecuteNoQuery(ExecuteSQL:String):Boolean;overload;virtual;
        function GetExecuteNoQuery(ExecuteSQL: String; ParameteList: TStringList):Boolean;overload;virtual;
        function GetParameteList: TStringList;overload;virtual;
        function GetParameteList(ParameterString:string;SplitString: String=';'):TStringList;overload;virtual;
        function BindList(QueryString: String;List:TStringList):TStringList;overload;virtual;
        procedure BindComboBox(InputComboBox: TComboBox; QueryString: String);virtual;
        procedure GetTableNames(Connection: TADOConnection; List: TStringList);overload;virtual;
        procedure GetTableNames(List: TStringList);overload;virtual;
        procedure GetFieldNames(TableName:string;List: TStringList);overload;virtual;
        procedure GetFieldNames(Connection: TADOConnection;TableName:string; List: TStringList);overload;virtual;
        function GetStringList: TStringList;virtual;
        procedure AddToComboboxItem(InputComboBox:TComboBox;List:TStringList);virtual;
        function getBackupInSertSQL(Connection: TADOConnection;TableName: string;
            InsertEachTime:Integer=1):TStringList;overload;virtual;
        function getBackupInSertSQL(QueryString: string;
            InsertEachTime:Integer=1):TStringList;overload;virtual;
        function StrNum(ShortStr, LongString: string): Integer;virtual;
        function StrSub(psInput: String; BeginPlace, CutLeng: Integer): String;virtual;
        function StrFind(ShortStr, LongStrIng: String): Integer;virtual;
        function replace(Source, Old, New: STRING): string;virtual;
        function StrCut(SourceString:WideString;BeginString:WideString;EndString:WideString):WideString ;virtual;
       published
         property ConnectionString:string write setConnectionString;
    end;
    procedure Register;

    implementation

    procedure Register;
    begin
    RegisterComponents('ADO', [TMyADO]);
    end;
    constructor TMyADO.Create(ConnectionString:String);
    begin
    try
    Self.Connection:=TADOConnection.Create(nil);
    Self.Connection.LoginPrompt:=False;
    Self.Connection.ConnectionString:=ConnectionString;
    Self.FConnectionString:=ConnectionString;
    Self.Connection.Connected:=true;
    Self.Query:=TADOQuery.Create(nil);
    Self.Table:=TADOTable.Create(nil);
    Self.Query.Connection:=Self.Connection;
    Self.Table.Connection:=Self.Connection;
    except
         //Destory;
         ShowMessage('创建ADO对象失败');
         Exit;
    end;
    end;
    destructor TMyADO.Destory;
    var i:Integer;
    begin
    try
    Self.Connection.Close;
    Self.Query.Close;
    Self.Table.Close;
    Self.Query.Free;
    Self.Table.Free;
    Self.Connection.Free;

    except

        for i:=0 to Self.ComponentCount-1 do
        if Self.Components[i]<>nil then
        Self.Components[i].Free;
        ShowMessage('内存可能溢出');
    end;
    end;
    procedure TMyADO.SetConnectionString(ConnectionString: string);
    begin
    if Self.Connection.Connected then
    Self.Connection.Connected:=False;
    Self.Connection.ConnectionString:=ConnectionString;
    Self.fConnectionString:=ConnectionString;
    Self.Connection.Connected:=true;
    end;
    function TMyADO.GetConnection():TADOConnection;
    begin
    Result:=Self.Connection;
    end;
    function TMyADO.GetConnection(ConnectionString: String): TADOConnection;
    var temp:TADOConnection;
    begin
        temp:=TADOConnection.Create(nil);
        temp.ConnectionString:=ConnectionString;
        temp.LoginPrompt:=False;
        Result:=temp;
    end;
    function TMyADO.GetQuery: TADOQuery;
    var TempQuery:TADOQuery;
    begin
    TempQuery:=TADOQuery.Create(nil);
    TempQuery.Connection:=Self.Connection;
    Result:=TempQuery;
    end;

    procedure TMyADO.GetQuery(InputQuery: TADOQuery;QueryString: String);
    begin
    InitQuery(InputQuery,QueryString);
    InputQuery.Open;
    end;
    procedure TMyADO.GetQuery(InputQuery:TADOQuery; QueryString: String;ParameterList: TStringList);
    begin
    try
    InputQuery.Connection:=Self.Connection;
    if CheckParaEqual(QueryString,ParameterList) then
    begin
         InitParameter(InputQuery,QueryString,ParameterList);
         InputQuery.Open;
    end;
    except

    end;
    end;
    function TMyADO.GetTable: TADOTable;
    begin
    Result:=TADOTable.Create(nil);
    end;
    function TMyADO.GetTable(TableName: String): TADOTable;
    var TempTable:TADOTable;
    begin
        TempTable:=TADOTable.Create(nil);
        TempTable.Connection:=Self.Connection;
        TempTable.TableName:=TableName;
        Result:=TempTable;
    end;
    function TMyADO.GetTable(TableName: String;Connection: TADOConnection):TADOTable;
    var TempTable:TADOTable;
    begin
        TempTable:=TADOTable.Create(nil);
        TempTable.Connection:=Connection;
        TempTable.TableName:=TableName;
        Result:=TempTable;
    end;
    function TMyADO.GetExecuteScalar(QueryString: String): Variant;
    var TempQuery:TADOQuery;
    begin
    try
    TempQuery:=GetQuery;
    InitQuery(TempQuery,QueryString);
    TempQuery.Open;
    Result:= TempQuery.Fields[0].Value;
    finally
       TempQuery.Free;
    end;
    end;
    function TMyADO.GetExecuteScalar(QueryString: String; ParameterList: TStringList): Variant;
    var tempQuery:TADOQuery;
    begin
    try
       tempQuery:=GetQuery;
    if CheckParaEqual(QueryString,ParameterList) then
    begin
       InitQuery(tempQuery,QueryString);
       tempQuery.Open;
       Result:=tempQuery.Fields[0].Value;
    end;
    finally

    tempQuery.Free;

    end;

    end;
    function TMyADO.GetParameteList: TStringList;
    begin
    Result:=TStringList.Create;
    end;
    function TMyADO.GetParameteList(ParameterString:string;SplitString: String=';'):TStringList;
    var i:Integer;
    tempstr:string;
    tempres:TStringList;
    begin
    tempres:=TStringList.Create;
          i:=Pos(SplitString,ParameterString);
          while i<>0 do
          begin
            tempstr:=Copy(ParameterString,0,(i-1));
            tempres.Add(tempstr);
            Delete(ParameterString,1,i+length(SplitString)-1);
            i:=Pos(SplitString,ParameterString);
          end;
          tempres.Add(ParameterString);
          Result:=tempres;
    end;

    function TMyADO.BindList(QueryString: String;List:TStringList):TStringList;
    var tempQuery:TADOQuery;
    begin
    try
    tempQuery:=GetQuery;
    InitQuery(tempQuery,QueryString);
    tempQuery.Open;
    tempQuery.First;
    List.Clear;
    while not tempQuery.Eof do
    begin
        if trim(VarToStr(tempQuery.Fields[0].Value))<>'' then
        List.Add(tempQuery.Fields[0].Value);
        tempQuery.Next;
    end;
    Result:=List;
    finally
          tempQuery.Free;
    end;
    end;
    procedure TMyADO.BindComboBox(InputComboBox: TComboBox; QueryString: String);
    var TempList:TStringList;
    begin
       TempList:=GetStringList;
       BindList(QueryString,TempList);
       AddToComboboxItem(InputComboBox,TempList);

       TempList.Free;
    end;
    function TMyADO.CheckParaEqual(QueryString: String; ParameterList: TStringList):Boolean;
    begin
       Result:= (StrNum(':',QueryString)=ParameterList.Count);
    end;
    procedure TMyADO.InitQuery(InputQuery: TADOQuery; QueryString: String);
    begin
    if InputQuery.Connection=nil then
    InputQuery.Connection:=Self.Connection;
    InputQuery.SQL.Clear;
    InputQuery.SQL.Add(QueryString);
    end;
    procedure TMyADO.GetTableNames(Connection: TADOConnection; List: TStringList);
    begin
    end;
    procedure TMyADO.GetTableNames(List: TStringList);
    begin
    Self.Connection.GetTableNames(List);
    end;
    procedure TMyADO.GetFieldNames(TableName:string;List: TStringList);
    begin
    Self.Connection.GetFieldNames(TableName,List);
    end;
    procedure TMyADO.GetFieldNames(Connection: TADOConnection;TableName:string; List: TStringList);
    begin
    Self.Connection.GetFieldNames(TableName,List);
    end;
    function TMyADO.GetStringList: TStringList;
    begin
    Result:=TStringList.Create;
    end;
    function TMyADO.GetExecuteNoQuery(ExecuteSQL: String): Boolean;
    var TempQuery:TADOQuery;
    begin
    try
        try
        TempQuery:=GetQuery;
        InitQuery(TempQuery,ExecuteSQL);
        TempQuery.ExecSQL;
        Result:=True;
        except
           Result:=False;
        end;
    finally
        TempQuery.Free;
    end;
    end;
    function TMyADO.GetExecuteNoQuery(ExecuteSQL: String;
    ParameteList: TStringList): Boolean;
    var TempQuery:TADOQuery;
    begin
    try
    TempQuery:=GetQuery;
    if CheckParaEqual(ExecuteSQL,ParameteList) then
    begin
         InitParameter(TempQuery,ExecuteSQL,ParameteList);
         TempQuery.ExecSQL;
         Result:=True;
    end else
    begin
        Result:=False;
        ShowMessage('参数个数不一致');
    end;
    finally
       TempQuery.Free;
       ParameteList.Free;
    end;
    end;
    procedure TMyADO.InitParameter(InputQuery: TADOQuery; QueryString: string;
    ParameterList: TStringList);
    var i:Integer;
    begin
    InitQuery(InputQuery,QueryString);
    for i:=0 to ParameterList.Count-1 do
    InputQuery.Parameters[i].Value:=ParameterList.Strings[i];
    end;

    function TMyADO.StrNum(ShortStr:string;LongString:string):Integer;     {测试通过}
    var
       i:Integer;
    begin
       i:=0;
       while pos(ShortStr,LongString)>0 do
          begin
             i:=i+1;
             LongString:=StrSub(LongString,(StrFind(ShortStr,LongString))+1,Length(LongString)-StrFind(ShortStr,LongString))
          end;
       Result:=i;
    end;

    function TMyADO.StrSub(psInput:String; BeginPlace,CutLeng:Integer):String;
    begin
        Result:=Copy(psInput,BeginPlace,CutLeng)
    end;

    function TMyADO.StrFind(ShortStr:String;LongStrIng:String):Integer;//在一个字符串中找某个字符的位置
    var
       locality:integer;
    begin
       locality:=Pos(ShortStr,LongStrIng);
       if locality=0 then
          Result:=0
       else
          Result:=locality;
    end;

    procedure TMyADO.AddToComboboxItem(InputComboBox: TComboBox;
    List: TStringList);
    var i,j:Integer;
    begin
        InputComboBox.Items.Clear;
       j:=List.Count-1;
       for i:=0 to j do
       InputComboBox.Items.Add(List.Strings[i]);
    end;
    function TMyADO.getBackupInSertSQL(Connection: TADOConnection;TableName: string;
            InsertEachTime:Integer=1):TStringList;
    var
    MyTable: TADOTable;
    TempString1, TempString2: string;
    RecordCount, FieldCount: Integer;
    i, j, k: Integer;
    ResultStringList: TStringList;
    tempstr: string;
    begin
         try
         ResultStringList:=TStringList.Create;
         MyTable:=TADOTable.Create(nil);
         Connection.LoginPrompt:=False;
         MyTable.Connection:=Connection;
         MyTable.TableName:=TableName;
         MyTable.Open;
         RecordCount:=MyTable.RecordCount -1;
         FieldCount:=MyTable.FieldCount-1;
         MyTable.First;
         j:=0;

          //另种快速做法
    TempString1:='';
         // MyTable.MoveBy(170);
           // while not MyTable.Eof do
       for k:=0 to   RecordCount do
        begin
            j:=j+1;
            TempString2:='';
            for i:=0 to FieldCount do
           case   MyTable.Fields[i].DataType of
           ftString,ftWideString,ftMemo,ftFmtMemo :
           begin

              tempstr:= ( Mytable.Fields[i].AsString);
              tempstr:=replace(tempstr,#13#10,'');
              tempstr:=replace( tempstr,'''','');
              TempString2:=TempString2+''''+ tempstr+''''+',';
           end;
           ftSmallint,ftInteger,ftWord,ftLargeint:
           begin
              TempString2:=TempString2+inttostr(MyTable.Fields[i].AsInteger)+',';
           end;
           ftBoolean:
           begin
              TempString2:=TempString2+ BoolToStr(MyTable.Fields[i].AsBoolean)+',';
           end;
           ftCurrency,ftBCD:
           begin
              TempString2:=TempString2+ CurrToStr(MyTable.Fields[i].AsCurrency)+',';
           end;
           ftFloat:
           begin
              TempString2:=TempString2+ FloatToStr(MyTable.Fields[i].AsFloat)+',';
           end;
           ftDate,ftDateTime:
           begin
             TempString2:=TempString2+ DateToStr(MyTable.Fields[i].AsDateTime)+',';
           end;
           ftUnknown:
           begin

           end;
           ftAutoInc:
           begin

           end;
           end;//end case;
            TempString2:=Copy(TempString2,1,Length(TempString2)-1);
            TempString1:=TempString1+'('+TempString2+'),'+#13#10;
            if j=InsertEachTime then
            begin
            TempString1:=Copy(TempString1,1,Length(TempString1)-3);
                //TempString1:='INSERT INTO '+ TableName+ ' VALUES'+#13#10+ TempString1+';';
            TempString1:='INSERT INTO '+ TableName+ ' VALUES'+ TempString1+';';
            ResultStringList.Add(TempString1);
            j:=0;
            TempString1:='';
            end;//end if

            MyTable.Next;

        end; //end while

        if Length( TempString1)>0 then
        begin
          TempString1:=Copy(TempString1,1,Length(TempString1)-3);
       //       TempString1:='INSERT INTO '+ TableName+ ' VALUES'+#13#10+ TempString1+';';
          TempString1:='INSERT INTO '+ TableName+ ' VALUES'+ TempString1+';';
          ResultStringList.Add(TempString1);
          j:=0;
          TempString1:='';
        end; //以上是第二种方法

        Result:=ResultStringList;
        finally
            MyTable.Free;
        end;
    end;

    function TMyADO.getBackupInSertSQL(QueryString: string;
            InsertEachTime:Integer=1):TStringList;
    var
    TempQuery: TADOQuery;
    TempString1, TempString2: string;
    RecordCount, FieldCount: Integer;
    i, j, k: Integer;
    ResultStringList: TStringList;
    tempstr: string;
    fieldnames:string;
    begin
         try
         ResultStringList:=TStringList.Create;
         TempQuery:=TADOQuery.Create(nil);
         Self.Connection.LoginPrompt:=False;
         TempQuery.Connection:=Self.Connection;
         TempQuery.SQL.Clear;
         TempQuery.SQL.Add(QueryString);
         TempQuery.Open;
         for j:=0 to TempQuery.FieldCount-1 do
         fieldnames:=fieldnames+ TempQuery.Fields[j].FieldName+',';
         fieldnames:=Copy(fieldnames,0,Length(fieldnames)-1);
         RecordCount:=TempQuery.RecordCount -1;
         FieldCount:=TempQuery.FieldCount-1;
         TempQuery.First;
         j:=0;
    TempString1:='';
         // TempQuery.MoveBy(170);
           // while not TempQuery.Eof do
       for k:=0 to   RecordCount do
        begin
            j:=j+1;
            TempString2:='';
            for i:=0 to FieldCount do
           case   TempQuery.Fields[i].DataType of
           ftString,ftWideString,ftMemo,ftFmtMemo :
           begin

              tempstr:= ( TempQuery.Fields[i].AsString);
              tempstr:=replace(tempstr,#13#10,'');
              tempstr:=replace( tempstr,'''','');
              TempString2:=TempString2+''''+ tempstr+''''+',';
           end;
           ftSmallint,ftInteger,ftWord,ftLargeint:
           begin
              TempString2:=TempString2+inttostr(TempQuery.Fields[i].AsInteger)+',';
           end;
           ftBoolean:
           begin
              TempString2:=TempString2+ BoolToStr(TempQuery.Fields[i].AsBoolean)+',';
           end;
           ftCurrency,ftBCD:
           begin
              TempString2:=TempString2+ CurrToStr(TempQuery.Fields[i].AsCurrency)+',';
           end;
           ftFloat:
           begin
              TempString2:=TempString2+ FloatToStr(TempQuery.Fields[i].AsFloat)+',';
           end;
           ftDate,ftDateTime:
           begin
             TempString2:=TempString2+ DateToStr(TempQuery.Fields[i].AsDateTime)+',';
           end;
           ftUnknown:
           begin

           end;
           ftAutoInc:
           begin

           end;
           end;//end case;
            TempString2:=Copy(TempString2,1,Length(TempString2)-1);
            TempString1:=TempString1+'('+TempString2+'),'+#13#10;
            if j=InsertEachTime then
            begin
            TempString1:=Copy(TempString1,1,Length(TempString1)-3);
                //TempString1:='INSERT INTO '+ TableName+ ' VALUES'+#13#10+ TempString1+';';
            TempString1:='INSERT INTO '+ StrCut(QueryString,'from','where')+'('+ fieldnames+')' + ' VALUES'+ TempString1+';';
            ResultStringList.Add(TempString1);
            j:=0;
            TempString1:='';
            end;//end if

            TempQuery.Next;

        end; //end while

        if Length( TempString1)>0 then
        begin
          TempString1:=Copy(TempString1,1,Length(TempString1)-3);
       //       TempString1:='INSERT INTO '+ TableName+ ' VALUES'+#13#10+ TempString1+';';
          TempString1:='INSERT INTO '+ StrCut(QueryString,'from','where')+'('+ fieldnames+')' + ' VALUES'+ TempString1+';';
          ResultStringList.Add(TempString1);
          j:=0;
          TempString1:='';
        end; //以上是第二种方法

        Result:=ResultStringList;
        finally
            TempQuery.Free;
        end;
    end;


    function TMyADO.replace(Source, Old, New: STRING): string;
    var
    p: Integer;
    begin
    WHILE POS( Old, Source ) <> 0 DO BEGIN
            p := POS( Old, Source );
            DELETE( Source, p, LENGTH( Old ) );
            INSERT( New, Source, p );
    {W}END;
    Result := Source;
    end;


    function TMyADO.StrCut(SourceString, BeginString,
    EndString: WideString): WideString;
    var beginPos,endPos:Integer;
    begin
    beginPos:=Pos(BeginString,SourceString);
    endPos:=Pos(EndString,SourceString);
    if (endPos=0) and (beginPos=0) then
    Result:=''
    else
    if endPos=0 then
    Result:=copy(SourceString,beginPos+ Length(BeginString), Length(SourceString)- beginPos- Length(BeginString)+1)
    else if beginPos=0 then
    Result:=Copy(SourceString,0,endPos)
    else
    Result:=copy(SourceString,beginPos+ Length(BeginString), endPos-beginpos- Length(BeginString));

    Result:=Trim(Result);
    end;


    end.
  • 相关阅读:
    评教说明
    使用firebird2.1与dbEntry.net做的设备报修小程序
    不知道为什么IList.Contains()总是返回FALSE
    DbEntry.net复合索引设置
    招生网上报名程序090512.rar
    aspnetdb生成
    推荐工具ActiveWriter
    dbEntry.net CK.K的高级应用
    tomcat添加虚拟子目录
    短信网关与短信猫
  • 原文地址:https://www.cnblogs.com/ghd2004/p/1274236.html
Copyright © 2020-2023  润新知