C# 依据DataTable创建透视表

/// < summary >

/// 依据原始数据创建透视表

/// 透视表:CreatePivotTable(scoreTable, "Course", "Score","No=学号;Name=姓名;Sex=性别", "No,Name,Sex");

/// summary >

/// < param name = "dataSource" > 原始数据 param >

/// < param name = "totalColumn" > distinct统计字段 param >

/// < param name = "valueColumn" > 数据字段 param >

/// < param name = "nullValue" > 不存在时的填充值 param >

/// < param name = "aliasColumns" > 生成的透视表列别名 eg: f1=栏位1;f2=栏位2 param >

/// < param name = "groupFields" > 分组字段 eg:f1,f2 param >

/// < returns > returns >

private DataTable CreatePivotTable( DataTable dataSource, string totalColumn, string valueColumn, string aliasColumns, string groupFields, object nullValue= null)

{

     if ( dataSource == null || string. IsNullOrEmpty( totalColumn) || string. IsNullOrEmpty( valueColumn) || string. IsNullOrEmpty( groupFields)) return null;

     int i;

     string[] arry, arry2;

     DataTable result, table;

     DataView dataView;

     DataRow newRow;

     DataColumn col;

     List< DataColumn> columns;

     Type valueType;

     StringBuilder wheresb;

     if ( nullValue == null) nullValue = DBNull. Value;

     string[] groupColumns = groupFields. Split( ',');

     result = new DataTable();

     //构建数据列

     columns = new List< DataColumn>();

     for ( i = 0; i < groupColumns. Length; i++)

    {

         col = new DataColumn( groupColumns[ i], dataSource. Columns[ groupColumns[ i]]. DataType);

         result. Columns. Add( col);

         columns. Add( col);

    }

     if ( columns. Count > 0) result. PrimaryKey = columns. ToArray();

     dataView = dataSource. DefaultView;

     dataView. RowFilter = "";

     table = dataView. ToTable( true, totalColumn);

     valueType = dataSource. Columns[ valueColumn]. DataType;

     columns. Clear();

     foreach ( DataRow row in table. Rows)

    {

         col = new DataColumn( row[ 0]. ToString(), valueType);

         result. Columns. Add( col);

         columns. Add( col);

    }

     //填充分组栏位数据

     table = dataView. ToTable( true, groupColumns);

     wheresb = new StringBuilder();

     foreach ( DataRow row in table. Rows)

    {

         newRow = result. NewRow();

         wheresb. Clear();

         for ( i = 0; i < groupColumns. Length; i++)

        {

             newRow[ groupColumns[ i]] = row[ groupColumns[ i]];

             wheresb. AppendFormat( " and {0}='{1}'", groupColumns[ i], row[ groupColumns[ i]]. ToString());

        }

         //查找数据填充剩余栏位的数据

         for ( i = 0; i < columns. Count; i++)

        {

             dataView. RowFilter = string. Format( "{0}='{1}' {2}", totalColumn, columns[ i]. ColumnName, wheresb. ToString());

             newRow[ columns[ i]] = dataView. Count > 0 ? dataView[ 0][ valueColumn] : nullValue;

        }

         result. Rows. Add( newRow);

    }

     dataView. RowFilter = "";

     //设置透视表列别名

     if (! string. IsNullOrEmpty( aliasColumns))

    {

         arry = aliasColumns. Split( ';');

         for ( i = 0; i < arry. Length; i++)

        {

             arry[ i] = arry[ i]. Trim();

             if ( arry[ i]. Length < 1) continue;

             arry2 = arry[ i]. Split( '=');

             if ( arry2. Length < 2) continue;

             arry2[ 0] = arry2[ 0]. Trim();

             arry2[ 1] = arry2[ 1]. Trim();

             if ( arry2[ 0]. Length < 1 || arry2[ 1]. Length < 1) continue;

             if (! result. Columns. Contains( arry2[ 0])) continue;

             result. Columns[ arry2[ 0]]. ColumnName = arry2[ 1];

        }

    }

     return result;

}