SQL查询选择一个范围

Question

我需要编写一个sql查询（在c＃中）选择Excel表格数据只有从C19开始的“C”列。但我不能指定结束单元格编号，因为更多的数据被添加到列中。因此，我需要知道如何指定列的结尾。请帮忙。我提到了我正在使用的查询。我附上了我使用的Excel表格的图像！并附上了输出datagridview！

//Generte Oracle Datatable 
      OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;" 
      + @"Data Source=" + textBox1.Text + ";" + @"Extended Properties=""Excel 12.0 Macro;HDR=Yes"""); 
      conn.Open(); 

      OleDbCommand ccmd = new OleDbCommand(@"Select * From [SPAT$]", conn); 
      OleDbDataAdapter adapter = new OleDbDataAdapter(ccmd);      
      DataTable Oracle = new DataTable(); 
      adapter.Fill(Oracle); 

      for (int y = 19; y < Oracle.Rows.Count; y++) 
      { 
       var value = Oracle.Rows[y][3].ToString();   
      } 
      dataGridView1.DataSource = Oracle.AsEnumerable().Where((row, index) => index > 3).CopyToDataTable();     

Answer 1

第一方法中，使用OLE查询：

OleDbCommand ccmd = new OleDbCommand(@"Select * From [SPAT$]", conn); 
OleDbDataAdapter da = new OleDbDataAdapter(ccmd); 
DataTable dt = new DataTable(); 
da.Fill(dt); 

for (int i = 19; i < dt.Rows.Count; i++) 
{ 
    var value = dt.Rows[i][3].ToString(); // here 3 refers to column 'C' 
} 

对于标准的基于数据表

dataGridView1.DataSource = dt.AsEnumerable() 
          .Where((row, index) => index >= 19) 
          .CopyToDataTable(); 

对于Column “C” 只

dataGridView1.DataSource = dt.AsEnumerable() 
         .Where((row, index) => index >= 19) 
         .Select(t => t[3].ToString()).ToList(); 

第二种方法中，使用Excel的COM对象：

using Excel = Microsoft.Office.Interop.Excel; 

Excel.Application xlApp = new Excel.Application(); 
Excel.Workbook xlWorkbook = xlApp.Workbooks.Open("path to book"); 
Excel.Worksheet xlSheet = xlWorkbook.Sheets[1]; // get first sheet 
Excel.Range xlRange = xlSheet.UsedRange; // get the entire used range 

int numberOfRows = xlRange.Rows.Count; 

List<string> columnValue = new List<string>(); 
// loop over each column number and add results to the list 

int c = 3; // Column 'C' 
for(int r = 19; r <= numberOfRows; r++) 
{ 
    if(xlRange.Cells[r,c].Value2 != null) // ADDED IN EDIT 
    { 
     columnValue.Add(xlRange.Cells[r,c].Value2.ToString()); 
    } 
}