search_j.pas

主要是介绍DELPHI三层应用以及分布式数据库的应用

unit search_j;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ComCtrls, ExtCtrls,ADODB, CheckLst;

type
  TFrm_search = class(TForm)
    PageControl1: TPageControl;
    TabSheet2: TTabSheet;
    Panel1: TPanel;
    btn_ok: TButton;
    btn_cancel: TButton;
    TreeView_search: TTreeView;
    Panel3: TPanel;
    Panel4: TPanel;
    Panel5: TPanel;
    Label7: TLabel;
    edit_value: TEdit;
    Label3: TLabel;
    combo_operator: TComboBox;
    Label5: TLabel;
    Combo_rel: TComboBox;
    btn_setup: TButton;
    byn_delete: TButton;
    btn_moresearch: TButton;
    Panel2: TPanel;
    Label1: TLabel;
    Splitter1: TSplitter;
    list_fields: TCheckListBox;

    procedure FormShow(Sender: TObject);
    procedure btn_setupClick(Sender: TObject);
    procedure byn_deleteClick(Sender: TObject);
    procedure btn_okClick(Sender: TObject);
    procedure List_fieldsClick(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure btn_cancelClick(Sender: TObject);
    procedure btn_moresearchClick(Sender: TObject);
    procedure btn_deleteClick(Sender: TObject);
    procedure btn_addClick(Sender: TObject);
    procedure list_fieldsClickCheck(Sender: TObject);

  private
    { Private declarations }
    procedure  HideColumn(i:integer;ifShow:boolean);
    procedure AddOperator(FieldType:string);
    function GetQueryStr() :string;
    function GenerateSql(tempNode:Ttreenode):string;
    function GetRelation(tempStr:String):string;
    function GetRelation2(tempStr:String):string;
    function GetOneSql(tempStr:String):string;
    function DealSearchText(tempStr:string):string;
  public
    { Public declarations }
//      TransADO:TadoQuery;
  end;

var
  Frm_search: TFrm_search;
  myNode:Ttreenode;
  myChildNode:Ttreenode;




implementation

uses cstm, data, Unit_wxp_j;


{$R *.dfm}

procedure TFrm_search.FormShow(Sender: TObject);
var
i:integer;
begin
        //向list_fields控件中增加字段

        //TransADO.Open ;
        for i:=0 to Frm_cstm.qcst.FieldList.Count-1  do
        begin
                list_fields.Items.Add  (Frm_cstm.qcst.Fields[i].FieldName  );
                //将每个字段的字段类型放在数组中
                //unit_wxp.FieldType[i]:= TransADO.Fields[i].DataType;

        end;

        //向树型控件中增加跟节点
        with treeview_search.Items do
        begin
                myNode:=add(nil,'以下为查询条件');
                //myChildNode:=addchild(myNode,'hello');

        end;

        //向list_delete中增加上一次过滤的字段
        //if unit_wxp.FilterArray >0 then
        //begin
             for i:=0 to list_fields.Items.Count -1 do
                 list_fields.checked[i]:=unit_wxp_j.FilterArray[i];
        //end;
            //list_fields.Items






end;

procedure TFrm_search.btn_setupClick(Sender: TObject);
var
        TempString:string;
        tempNode: Ttreenode;
        NodeString:string;
begin
        if edit_value.Text='' then
        begin
                ShowMessage('请输入查询条件');
                exit;
        end
        else if list_fields.ItemIndex <0 then
               showmessage('请选择一个字段')
        else
        begin
                with treeview_search do
                begin
                if selected=nil then
                        tempNode:=myNode

                else
                        tempNode:=selected;

                NodeString:=list_fields.Items.Strings[list_fields.itemindex]+
                unit_wxp_j.GetOperator(combo_operator.Text )+DealSearchText(edit_value.Text)
                +'('+unit_wxp_j.GetRelation(combo_rel.Text )+')';
                if (copy(tempNode.text,1,6)='子条件') or (tempNode=myNode) then
                        myChildNode:=Items.addchild(tempNode,NodeString)
                else
                begin
                        tempNode:=tempNode.Parent ;
                        myChildNode:=Items.addchild(tempNode,NodeString);
                end;
        
               end;
        end;
    treeview_search.FullExpand ;
end;



procedure TFrm_search.byn_deleteClick(Sender: TObject);
begin
        //with treeview_search do
        //begin
        if treeview_search.Selected =nil then
           showmessage('请选择删除结点')
        else if treeview_search.Selected =myNode then
             showmessage('根结点不能删除')
        else
           treeview_search.Items.Delete(treeview_search.Selected );
                //items.Delete(itemindex)
        //end;
end;

procedure TFrm_search.btn_okClick(Sender: TObject);
var
   i:integer;
begin
        //根据查询语句重新建立查询
        //查询以前先关闭连接然后打开连接
   //     showmessage(GetQueryStr);
        if GetQueryStr<>'' then
            //showmessage(GetQueryStr);
            begin
                 with Frm_cstm.qcst  do begin
                  filter:=GetQueryStr;
                  filtered:=true;
                  end ;
            end;

        //将被过滤字段保存在数组中
        {if list_fields.Items.Count>0 then
        begin
             //setlength(unit_wxp.filterarray,list_delete.Items.Count );
             //unit_wxp.FilterNum := list_delete.Items.Count;
             for i:=0 to list_fields.Items.Count-1 do
             begin
                 //unit_wxp.FilterArray[i]:=list_delete.Items.Strings[i];
                 unit_wxp.FilterArray[i] :=list_fields.checked[i];
                 if list_fields.checked[i]=true then
                 HideColumn(i,false)
                 else
                 HideColumn(i,true);
             end;


        end; }
        //关闭窗口

        close;


end;

procedure TFrm_search.List_fieldsClick(Sender: TObject);
begin
        edit_value.SetFocus ;
        AddOperator(unit_wxp_j.GetFieldType(list_fields.ItemIndex ) );
        //showmessage(inttostr(list_fields.ItemIndex));
end;


procedure TFrm_search.FormClose(Sender: TObject;
  var Action: TCloseAction);
begin
        action:=cafree;
end;

procedure TFrm_search.btn_cancelClick(Sender: TObject);
begin
        close;
end;

//添加子条件
procedure TFrm_search.btn_moresearchClick(Sender: TObject);
var
        tempNode:Ttreenode;
begin
         with treeview_search  do
         begin
               if Selected=nil then
                       tempNode:=myNode
               else
                       tempNode:=selected;
               if (copy(tempNode.text,1,6)<>'子条件') and (tempNode<>myNode) then
                begin
                        myChildNode:=items.AddChild(tempNode,tempNode.Text );
                        tempnode.Text :='子条件('+unit_wxp_j.GetRelation(combo_rel.Text )+')';
                end
               else
               tempNode:=items.addChild(tempNode,'子条件('+unit_wxp_j.GetRelation(combo_rel.Text )+')');

         end;
         treeview_search.FullExpand ;
end;

//增加过滤字段事件
procedure TFrm_search.btn_deleteClick(Sender: TObject);
var
   tempIndex:integer;
begin
{        if list_fields.ItemIndex <0 then
        begin
                showmessage('请选择一个过滤字段');
                exit;
        end;
        tempIndex:=list_delete.Items.IndexOf(list_fields.Items.Strings[list_fields.itemindex]);
        if tempIndex<0 then
            begin
            list_delete.Items.Add (list_fields.Items.Strings[list_fields.itemindex]);
            //form_partinfo.DBGrid1.Columns.Items[list_fields.itemindex].Visible :=false;


            end
        else
            showmessage('已经过滤了该字段');      }
end;


//恢复过滤字段
procedure TFrm_search.btn_addClick(Sender: TObject);
var
   tempIndex:integer;
begin
{     if list_delete.ItemIndex <0 then
        showmessage('请选择恢复字段')
     else
     begin
        tempIndex:=list_fields.Items.IndexOf(list_delete.Items.Strings[list_delete.ItemIndex]);
        list_delete.DeleteSelected ;
        form_partinfo.DBGrid1.Columns[tempIndex].Visible :=true;
     end;  }
end;




//自定义函数过程
/////////////////////////////////////////////////////////////////
//产生查询语句
 function TFrm_search.GetQueryStr() :string;
 var
        SearchSql:string;
 begin
        //从树型控件中得到sql语句
         SearchSql:=GenerateSql(myNode);
         if SearchSql='' then
            result:=''
         else
            result:=unit_wxp_j.SearchSql +SearchSql ;

 end;
 //////////////////////////////////////////////////////////////////
//根据不同的字段类型，添加不通的操作符
procedure  TFrm_search.AddOperator(FieldType:string);
begin
     //showmessage(FieldType);
     if (FieldType='number') or (FieldType='money') then
        begin

        with combo_operator do
        begin
        clear;
        text:= '等于(=)';
        Items.Add('等于(=)');
        Items.Add('不等于(<>)');
        Items.Add('大于(>)');
        Items.Add('小于(<)');
        Items.Add('大于等于(>=)');
        Items.Add('小于等于(<=)');
        end;
        end
     else
        begin
        with combo_operator do
        begin
        Clear ;
        text:='等于(=)';
        Items.Add('等于(=)');
        Items.Add('不等于(<>)');
        Items.Add('相似(like)');
        end;

        end;
end;
//////////////////////////////////////////////////////////////////

function TFrm_search.GenerateSql(tempNode:Ttreenode) :string;
var
        tempSql:string;
begin
        if tempNode=nil then
       begin
           Result:='';
           exit;
       end;

       if tempNode=myNode then
       begin
           tempSql:=GenerateSql(tempNode.getFirstChild );
           Result:=tempsql;
           exit;
       end;

       if  tempNode.getNextSibling  <>nil then
       begin
           tempSql:=GenerateSql(tempNode.getNextSibling  );
           if copy(tempNode.text,1,6)='子条件'  then
           begin
               if (GenerateSql(tempNode.getFirstChild )<>'') and (tempSql<>'') then
               tempSql:='('+GenerateSql(tempNode.getFirstChild )+')'+' '
               +Getrelation(tempNode.Text )+ ' '+tempSql
               else if (GenerateSql(tempNode.getFirstChild )<>'') and (tempSql='') then
               tempSql:='('+GenerateSql(tempNode.getFirstChild )+')';
               //tempSql:=tempSql+ ' '; //+ Getrelation(tempNode.Text );
               Result:= tempSql;
           end
           else if  copy(tempNode.text,1,6)<>'子条件'  then
           begin
                if tempSql<>'' then
                tempSql:=GetOneSql(tempNode.Text ) + ' ' +Getrelation2(tempNode.Text)
                +' '+ tempSql
                else
                tempSql:=GetOneSql(tempNode.Text );
                Result:=tempSql;
           end;
           exit;
        end;

       if  tempNode.getNextSibling  =nil then
       begin
           if copy(tempNode.text,1,6)='子条件'  then
           begin
               if  GenerateSql(tempNode.getFirstChild )<>'' then
               tempSql:='('+GenerateSql(tempNode.getFirstChild )+')'+' ';
               //+Getrelation(tempNode.Text );
               //tempSql:=tempSql+ ' '; //+ Getrelation(tempNode.Text );
               Result:= tempSql;
           end
           else if  copy(tempNode.text,1,6)<>'子条件'  then
           begin
                tempSql:=GetOneSql(tempNode.Text );
                Result:=tempSql;
           end;
           exit;
       end;
end;

///////////////////////////////////////////////////////////
//判断是or还是and
//如'子条件(or),分离出or'
function TFrm_search.Getrelation(tempStr:string):string;
begin
      if  copy(tempStr,8,2)='or' then
        Result:='or'
      else
        Result:='and';
end;

//另一个判断是or或者and的函数
//如'名称=1(and)，分离出and'
function TFrm_search.Getrelation2(tempStr:string) :string;
var
tempPos:integer;
begin
        tempPos:=pos('(',TempStr)-1;
        if copy(TempStr,tempPos+2,2)='or' then
                Result:='or'
        else
                Result:='and';
end;
//自定义函数过程结束


//定义函数获得具体查询部分
function TFrm_search.GetOneSql(tempStr:string) :string;
var
        tempPos:integer;
begin
        tempPos:=pos('(',TempStr)-1;
        Result:=copy(TempStr,1,tempPos);

end;




procedure TFrm_search.list_fieldsClickCheck(Sender: TObject);
var
   tempIndex:integer;
begin
     //tempIndex:=list_delete.Items.IndexOf(list_fields.Items.Strings[list_fields.itemindex]);
     //if tempIndex<0 then
     //       list_delete.Items.Add (list_fields.Items.Strings[list_fields.itemindex])
     //   else
     //       list_delete.Items.Delete(tempIndex);
end;


procedure  TFrm_search.HideColumn(i:integer;ifShow:boolean);
var
tempIndex:integer;
begin
     tempIndex:=i;
     //showmessage(inttostr(tempIndex));
     case unit_wxp_j.WhichForm  of
{//     1:form_partinfo.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     2:form_partorder.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     3:form_partout.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     4:form_partin.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     5:form_partsell.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     6:form_machinetest.DBGrid1.Columns[tempIndex].Visible :=ifshow;
 }    1:Frm_cstm.DBGrid1.Columns[tempIndex].Visible :=ifshow;
     end;


end;


//根据字段的属性来决定一些查询语句的格式
function  TFrm_search.DealSearchText(tempStr:string):string;
begin
     if  unit_wxp_j.GetFieldType(list_fields.ItemIndex )= 'string' then
         Result:='''' + tempstr +''''
     else
          Result:=tempStr;




end;

end.