uconditionquery.cpp

我写的抽象语法树

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "UConditionQuery.h"
#include "BooleanExp.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TConditionQuery *ConditionQuery;
//2007.08 宋双、田奇
//---------------------------------------------------------------------------
__fastcall TConditionQuery::TConditionQuery(TComponent* Owner,TListView* ref)
        : TForm(Owner)
{
    refView=ref;
    m_iType=0;
}
//**************************************************************
__fastcall TConditionQuery::TConditionQuery(TComponent* Owner,TDataSet* DataSet)
        : TForm(Owner)
{
    m_iType=1;
    m_DataSet=DataSet;
    if(DataSet->Filter!="")
        m_sOriginFilter="("+DataSet->Filter+")";
    m_slFieldLabels = new TStringList();
    m_slFieldNames = new TStringList();
    m_VFieldCount=0;
}
//---------------------------------------------------------------------------

void __fastcall TConditionQuery::FormShow(TObject *Sender)
{
    if(m_iType==0)//ListView
    {
        int size=refView->Columns->Count-1;
        for(int i=1;i<size;i++)
        {
            ComboBox1->Items->Add(refView->Column[i]->Caption);
        }
        ComboBox1->ItemIndex=0;
        ComboBox2->ItemIndex=0;
    }
    else//DataSet
    {
        ListBox1->Clear();
        ComboBox1->Clear();
        ComboBox3->Clear();

        //filling FieldName
        ParseFields();
        ComboBox1->Items = m_slFieldLabels;
        //combo locate
        ComboBox1->ItemIndex=0;
        ComboBox2->ItemIndex=0;
    }
}
//---------------------------------------------------------------------------

void __fastcall TConditionQuery::ComboBox3DropDown(TObject *Sender)
{
   AnsiString FieldName,Val;
   Screen->Cursor=crHourGlass;
   ComboBox3->Clear();
   int index=ComboBox1->ItemIndex;
   if(m_iType==0)
   {
       int size=refView->Items->Count-1; //ListView的Item个数
       for(int i=0;i<=size;i++)
       {
           AnsiString fieldValue=refView->Items->Item[i]->SubItems->Strings[index];
           if(ComboBox3->Items->IndexOfName(fieldValue.Trim())==-1)     //没用？
           ComboBox3->Items->Add(fieldValue);
       }
   }
   else
   {
       //filling field valid value
       ComboBox3->Clear();
       TBookmark Bookmark = m_DataSet->GetBookmark();
       try
       {
           m_DataSet->DisableControls();
           for(m_DataSet->First(); !m_DataSet->Eof; m_DataSet->Next())
           {
                FieldName = m_slFieldNames->Strings[ComboBox1->ItemIndex];
                Val=m_DataSet->FieldByName(FieldName)->AsString;

                if(ComboBox3->Items->IndexOf(Val)==-1 && Val!="")
                ComboBox3->Items->Add(Val);
           }
       }
        __finally
       {
           m_DataSet->GotoBookmark(Bookmark);
           m_DataSet->EnableControls();
           m_DataSet->FreeBookmark(Bookmark);
       }
   }
   Screen->Cursor=crDefault;
}
//---------------------------------------------------------------------------


void __fastcall TConditionQuery::BitBtn_CancelClick(TObject *Sender)
{
    this->Close();
}
//---------------------------------------------------------------------------

void __fastcall TConditionQuery::BitBtn_AddConditionClick(TObject *Sender)
{
    if(m_iType==0)
    {
        AnsiString relation;
        if(RadioGroup1->ItemIndex==0)
            relation="并且";
        else
            relation="或者";
        if(ListBox1->Items->Count>0)
        ListBox1->Items->Add(relation);
        ListBox1->Items->Add(ComboBox1->Text+" "+ComboBox2->Text+" "+ComboBox3->Text);
    }
    else
    {
        AnsiString sFieldName, sRelation, sRelationDisplay, sOp, sCon;

        sFieldName = m_slFieldNames->Strings[ComboBox1->ItemIndex];
        if(RadioGroup1->ItemIndex==0)
        {
            sRelation=" and ";
            sRelationDisplay=" 并且 ";
        }
        else
        {
            sRelation=" or ";
            sRelationDisplay=" 或者 ";
        }
        vRelation.push_back(sRelation);
        switch(ComboBox2->ItemIndex)
        {
            case 0: sOp = " = ";
                break;
            case 1: sOp = " > ";
                break;
            case 2: sOp = " < ";
                break;
            case 3: sOp = " like ";
        }
        sCon = sFieldName + sOp;

        if(m_DataSet->FieldByName(sFieldName)->DataType==ftFloat
         ||m_DataSet->FieldByName(sFieldName)->DataType==ftInteger
         ||m_DataSet->FieldByName(sFieldName)->DataType==ftSmallint)
        sCon += ComboBox3->Text;
        else if(ComboBox2->ItemIndex==3)
                 sCon += "'%"+ComboBox3->Text+"%'";
             else
                 sCon += "'"+ComboBox3->Text+"'";

        vCondition.push_back(sCon);

        if(ListBox1->Items->Count>0)
          ListBox1->Items->Add(sRelationDisplay);

        ListBox1->Items->Add(ComboBox1->Text+" "+
                             ComboBox2->Text+ " "+
                             ComboBox3->Text);
  }
}
//---------------------------------------------------------------------------

void __fastcall TConditionQuery::BitBtn_OKClick(TObject *Sender)
{
    AnsiString TempFilter;
    if(ListBox1->Items->Count==0)
    {
        return;
    }
    int index=0;
    int size=ListBox1->Items->Count;
    exp=Expr(index,size);
    //
    if(m_iType==0)
    {
        vector<int>  vec=exp->FiltListView(refView);  //生成抽象语法树
        int tmp=vec.size();
        refView->MultiSelect=true;   //开始过滤
        int viewsize=refView->Items->Count;
        for(int i=0;i<viewsize;i++)
        {
            refView->Items->Item[i]->Selected=true;
        }
        for(int i=0;i<vec.size();i++)
        {
            refView->Items->Item[vec[i]]->Selected=false;
        }
        viewsize=viewsize-vec.size();                                                //删除选中的
        refView->Items->BeginUpdate();
        for(int i=0;i<viewsize;i++)
        {
            refView->Selected->Delete();
        }
        refView->Items->EndUpdate();
        refView->Repaint();
        exp->destory();
        refView->MultiSelect=false;
    }
    else
    {
        AnsiString sFilter;
        sFilter=m_sOriginFilter;
        for(unsigned int i=0;i<vCondition.size();i++)
        if(sFilter=="")
            sFilter+=vCondition[i];
        else
            sFilter+=vRelation[i]+vCondition[i];
        try
        {
            m_DataSet->Filter=sFilter;
            m_DataSet->Filtered=true;
            if(m_DataSet->RecordCount==0)
            {
                ShowMessage("没有满足条件的记录！");
                m_DataSet->Filter=m_sOriginFilter;
                m_DataSet->Filtered=true;
            }
        }
        catch(...)
        {
            ShowMessage("添加的条件错误，请重新选择条件！");
            m_DataSet->Filter=m_sOriginFilter;
            m_DataSet->Filtered=true;
            return;
        }
    }
    ModalResult=mrOk;
}
//---------------------------------------------------------------------------

BooleanExp*  TConditionQuery::Factor(int& index,int size)
{
     BooleanExp* exp;
     int pos,end=0;
     AnsiString tmp=ListBox1->Items->Strings[index];
     int length=tmp.Length();
     pos=tmp.Pos("<");
     if(pos==0)
     pos=tmp.Pos(">");
     if(pos==0)
     pos=tmp.Pos("=");
     if(pos==0)
     {
        pos=tmp.Pos("like");
        end=pos+3;
     }
     if(end!=0)
     {
        exp=new VariableExp(tmp.SubString(1,pos-1),"like",tmp.SubString(end+1,length-end));
     }
     else
     {
         exp=new VariableExp(tmp.SubString(1,pos-1),tmp[pos],tmp.SubString(pos+1,length-pos));
      }

     index++;
     return exp;                         //生成子节点
}


BooleanExp*  TConditionQuery::Term(int& index,int size)
{
     BooleanExp* exp;
     exp=Factor(index,size);
     while(index<size&&ListBox1->Items->Strings[index]=="并且")
     {
        index++;
        exp=new AndExp(exp,Factor(index,size));
     }
     return exp;                                                     //生成and树
}

BooleanExp*  TConditionQuery::Expr(int& index,int size)
{
     BooleanExp* exp;
     exp=Term(index,size);
     while(index<size&&ListBox1->Items->Strings[index]=="或者")
     {
       index++;
       exp=new OrExp(exp,Expr(index,size));
      }
      return exp;
}                                                                    //生成or树,与总树
//*****************************************************
void __fastcall TConditionQuery::ParseFields()
{
  for(int i=0; i<m_DataSet->Fields->Count; i++)
    if( m_DataSet->Fields->Fields[i]->Tag != 1&& m_DataSet->Fields->Fields[i]->Visible)
    {
      m_slFieldNames->Add(m_DataSet->Fields->Fields[i]->FieldName);
      m_slFieldLabels->Add(m_DataSet->Fields->Fields[i]->DisplayName);
      m_VFieldCount++;
    }
}