C++山寨C#中的DataTable

原帖地址：http://www.cnblogs.com/hlxs/archive/2013/05/31/3110036.html

简单介绍一下DataTable。DataTable主要基于表、行、单元格。行用集合包装单元格，表用集合包装行，大致就是这样。DataColumn表示单元格，DataColumn中的字段还挺多的，在实际应用中我们可能只想用它来存一个int型的数据；DataColumnCollection中用一个ArrayList封装DataColumn，表示一些单元格的集合；DataRow直接在DataColumnCollection的基础上提供一些方法，成为行记录。而DataRowCollection则用集合的方式封装DataRow成为表，但它不是以线性、链表等方式，而是基于红黑树RBTree<DataRow>，主要是查询和删除比较方便，而DataTable则是DataRowCollection的封装，对看了DataTable整个实现的大致代码，我不得吐槽一下：这它妈是把牛刀，我们每天用它来切菜，用着还挺方便。DataTable提供了很强大的功能，但是我们基本不需要，有时候基本上是得到一个DataTable，啥都不做，直接绑定，最常用的也就Update和Insert，Select和Delete则次之。当然你会说避免使用DataTable，当然还有人说C#......

OK废话到此结束，今天我想做说的是用C++来实现DataTable。大致思路还是按照C#中的来，功能没有C#中的强大，但增删改查的功能还是有的，基本还是个人练习，把代码放出来跟大家讨论一下。基本上是STL中几个集合的运用。在我的实现在并没有使用红黑树，而是用list<DataRow*>代替了，主要类的头文件如下：

DataColumn的实现代码如下，主要是对几个字段的封装。源码共享

#pragma once
class DataTable;
#include <iostream>
using namespace std; 

template<typename T>
class TDataColumn
{
public:
    TDataColumn():columnName(string()),caption(string())
    {

    }

    TDataColumn(const string& _columnName):columnName(_columnName),caption(string())
    {

    }

virtual ~TDataColumn()
    {

    }

void Caption(const string& _caption)
    {
        caption=_caption;
    }
string Caption()
    {
return caption.size() ?caption:columnName; 
    }

void  ColumnName(const string& _columnName)
    {
        columnName=_columnName;
    }
string ColumnName()
    {
return columnName;
    }

void Value(const T& _value)
    {
        value=_value;
    }
    T Value()
    {
return value;
    }

int ObjectId()
    {
return objectId;
    }

void Table(DataTable* tb)
    {
        table=tb;
    }

    DataTable* Table()
    { 
return table;
    }

string TypeName()
    {
return typeid(T).name();
    }

protected: 
int objectId; 
string columnName;
string caption;
    T value;
    DataTable* table;
}; 


class DataColumn:public TDataColumn<string>
{
public:
    friend class DataColumnCollection;
    friend class DataTable;
    DataColumn():TDataColumn<string>() 
    {
         objectId=++objectCountId;
    }

    DataColumn(const DataColumn& dc)
    {
*this=dc; 
    }

    DataColumn& operator=(const DataColumn& dc)
    {
        objectId=++objectCountId;
        columnName=dc.columnName;
        caption=dc.caption;
        value=dc.value;
        table=dc.table;
return *this;
    }

    DataColumn(const string& _columnName):TDataColumn<string>(_columnName)
    {
         objectId=++objectCountId;
    }

bool operator==(const DataColumn& dc)
    {
return objectId==dc.objectId;
    }

bool operator!=(const DataColumn& dc)
    {
return objectId!=dc.objectId;
    }

bool operator<(const DataColumn& dc)
    {
return objectId<dc.objectId;
    }

bool operator>(const DataColumn& dc)
    {
return objectId>dc.objectId;
    }

void Show()
    {
        cout<<"columnName:"<<columnName.data()<<",caption:"<<Caption().c_str()<<",value:"<<value.data()<<endl;
    }

private: 
static volatile int objectCountId;
}; 

其他文件的头文件如下：

#pragma once
#include <iostream>
using namespace std; 
#include <assert.h> 
#include <vector> 
#include <list>
#include <map>
#include "DataColumn.h" 
#include "StringHelper.h"

class DataColumnCollection;
class DataRow;
class DataRowCollection;
class DataTable;

class DataColumnCollection
{
public:
     friend class DataTable;
     friend class DataRow;
     friend class DataRowCollection;
     DataColumnCollection(DataTable* table);
~DataColumnCollection();
void Add(DataColumn* dc);
void Add(DataColumn* dc,size_t index);

     DataColumn& Add(const string& columnName);

bool Contains(const string& columnName);
void Clear();
     size_t Count(); 
int IndexOf(const string& columnName);

void Remove(DataColumn& dc);
void Remove(const string& columnName);
void RemoveAt(size_t index);

void CopyTo(DataColumnCollection* arr, size_t index);

     DataColumn& operator[](size_t index);
     DataColumn& operator[](const string& columnName);

void Table(DataTable* tb);
     DataTable* Table();
private:
void Add(DataColumn* dc,size_t index,DataColumnCollection* collect);
void RemoveAt(size_t index,DataColumnCollection* collect);
void InitData();
    DataColumnCollection(); 
    vector<DataColumn*> dlist;
    map<int,DataColumn*> nameList;
    DataTable* table;
};

class DataRow
{
public:
    friend class DataTable;
    friend class DataRowCollection;
    friend class DataColumnCollection;
~DataRow();
void Table(DataTable* tb); 
    DataTable* Table();

    DataColumnCollection& Columns();
    DataColumn& operator[](size_t index);
    DataColumn& operator[](const string& columnName);
bool operator=(const DataRow& dr);
private:
    DataRow();
void Remove(DataColumn& dc);
void RemoveAt(size_t index); 
    DataColumnCollection* columns;
    DataTable* table;    
int rowId;
static volatile int rowIdCount;
};

class DataRowCollection
{
public:
     friend class DataTable;
     friend class DataColumnCollection;
     DataRowCollection(DataTable* table);
~DataRowCollection();
void Add(DataRow* dc);  
void Clear();
     size_t Count();  
void Remove(DataRow* dc); 
void RemoveAt(size_t index); 
     DataRow& operator[](size_t index); 
void Table(DataTable* tb);
     DataTable* Table();
private:
    DataRowCollection(); 
    list<DataRow*> drlist; 
    DataTable* table;
};


class DataTable
{
public:
    friend class DataColumnCollection;
    friend class DataRowCollection;
    DataTable();
    DataTable(const string& _tableName);
~DataTable();

    DataColumnCollection& Columns();
    DataRowCollection& Rows();

string TableName();
void TableName(const string& _tableName);
    DataRow& operator[](size_t index);
void Clear(); 
    DataRow* NewRow();
    vector<DataRow*>* Select(const string& columnName,const string& value) ;
private:
void InitData();
    DataColumnCollection* dcCollect;
    DataRowCollection* drCollect;
string tableName;
};

测试代码如下：

#include <iostream>
using namespace std;
#include <sstream>
#include "DataColumn.h" 
#include "DataTable.h"
#include "OperationTimer.h"

int main( )
{  
    DataTable dt;
for(size_t i=0;i<10;i++)
    {
string s("column");
        s.push_back(char('0'+i));
        DataColumn *dc=new DataColumn(s); 
        dt.Columns().Add(dc);
    }

for(int j=0;j<10;j++)
    {
        DataRow* dr=dt.NewRow();
for(int i=0;i<10;i++)
        {
string s("row");
            s.push_back(char('0'+j));
            s.push_back(char('0'+i));
            (*dr)[i].Value(s)  ;
        }
        dt.Rows().Add(dr);
    }

int rowCount=dt.Rows().Count();
int columnCount=dt.Columns().Count();
    cout<<"共"<<rowCount<<"行"<<columnCount<<"列"<<endl;
    rowCount=rowCount/2;
    columnCount=columnCount/2;
    cout<<"第"<<rowCount<<"行"<<columnCount<<"列的值为："<<dt[rowCount][columnCount].Value().c_str()<<endl;

    dt.Columns().Add(new DataColumn("column10"));
    dt.Columns().Add(new DataColumn("column11"));
    cout<<"新增两列后："<<endl;
    rowCount=dt.Rows().Count();
    columnCount=dt.Columns().Count();
    cout<<"共"<<rowCount<<"行"<<columnCount<<"列"<<endl;
    rowCount=rowCount/2;
    columnCount=columnCount/2;
    cout<<"第"<<rowCount<<"行"<<columnCount<<"列的值为："<<dt[rowCount][columnCount].Value().c_str()<<endl;
    cout<<"删除一行一列后："<<endl;
    dt.Columns().RemoveAt(4); 
    dt.Rows().RemoveAt(2);

    rowCount=dt.Rows().Count();
    columnCount=dt.Columns().Count();
    cout<<"共"<<rowCount<<"行"<<columnCount<<"列"<<endl;
    rowCount=rowCount/2;
    columnCount=columnCount/2;
    cout<<"第"<<rowCount<<"行"<<columnCount<<"列的值为："<<dt[rowCount][columnCount].Value().c_str()<<endl<<endl;

    cout<<"查询列名为column3，值为row43的行，数据如下："<<endl;
    vector<DataRow*>* vect=dt.Select("column3","row43");
for(size_t i=0;i<vect->size();i++)
    {
        DataColumnCollection& dcCollect= (*vect)[i]->Columns();
for(size_t j=0;j<dcCollect.Count();j++)
        {
            dcCollect[j].Show();
        }
    }
    delete vect;  



    getchar();
return 0;
}

 结构截图：

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