如何使用searchstring搜索数据表中的行?
嗨,我想在我的DataTable中搜索行,我试试这个:
protected void imggastsuche_Click(object sender, EventArgs e) { string searchstring = txtgastsuche.Text; DataTable tb = DataBaseManager.GetDataTable(mysqlconnectionstring); DataRow[] foundRows = tb.Select("FIRSTNAME,LASTNAME,NAME,COMPANY,TIMEFROM,TIMETO,CREATOR Like '%" + searchstring + "%'"); tb = foundRows.CopyToDataTable(); this.ListView.DataSource = tb; this.ListView.DataBind(); }
但我的字符串中有错误。 如果我想搜索这个列,我该怎么办?
您收到错误,因为Select
的参数是filterExpression并且您已经传递了所有列。 将filterExpression理解为sql中的WHERE
子句。 您想要所有列,但只想过滤一个。 无论如何,您都可以获得所有列,因为它们都是DataTable
/ DataView
一部分,因此您无需明确列出它们。
您可以使用DataTable.Select
, DatView.RowFilter
方法或LINQ-to-DataSet
:
LINQ-To-DataSet(我更喜欢):
var filtered = tb.AsEnumerable() .Where(r => r.Field("CREATOR").Contains(searchstring));
ADO.NET( DataTable.Select
):
DataRow[] filteredRows = tb.Select("CREATOR LIKE '%" + searchstring + "%'");
ADO.NET( DataView.RowFilter
):
tb.DefaultView.RowFilter = "CREATOR LIKE '%" + searchstring + "%'";
如果要在任何列中搜索此string
,请执行以下操作:
DataRow[] filteredRows = tb.Select("FIRSTNAME LIKE '%" + searchstring + "%' OR LASTNAME LIKE '%" + searchstring + "%' OR NAME LIKE '%" + searchstring + "%' OR COMPANY LIKE '%" + searchstring + "%' OR CREATOR LIKE '%" + searchstring + "%'");
与Linq一样:
var filtered = tb.AsEnumerable() .Where(r => r.Field("FIRSTNAME").Contains(searchstring) || r.Field ("LASTNAME").Contains(searchstring)) || r.Field ("NAME").Contains(searchstring) || r.Field ("COMPANY").Contains(searchstring) || r.Field ("CREATOR").Contains(searchstring));
如果其他人需要专门返回DataTable,您可以使用以下代码:
DataTable dtResult= tb.Select("CREATOR LIKE '%"+searchstring+"%'").CopyToDataTable();
我刚刚为DataTable类做了一个扩展方法 。 它返回一个只包含所需行的新数据表。
public static DataTable SearchInAllColums(this DataTable table, string keyword, StringComparison comparison) { if(keyword.Equals("")) { return table; } DataRow[] filteredRows = table.Rows .Cast() .Where(r => r.ItemArray.Any( c => c.ToString().IndexOf(keyword, comparison) >= 0)) .ToArray(); if (filteredRows.Length == 0) { DataTable dtProcessesTemp = table.Clone(); dtProcessesTemp.Clear(); return dtProcessesTemp; } else { return filteredRows.CopyToDataTable(); } }
用法:
DataTable dataTable = getData(); dataTable.SearchInAllColums(Keyword, StringComparison.OrdinalIgnoreCase);
您可以构建要在select中使用的查询。
if(TextBoxCusName.Text != "") { query = "CustomerName LIKE '%" + TextBoxCusName.Text.Trim()+"%' AND "; } if(TextBoxCusContact.Text != "") { query = query + "CustomerNo LIKE '%" + TextBoxCusContact.Text.Trim() + "%' AND "; } if(TextBoxVehicleNo.Text != "") { query = query + "VehicleNo LIKE '%" + TextBoxVehicleNo.Text.Trim()+"%'"; } if(query.EndsWith("AND ")) { query = query.Remove(query.Length - 4); } DataRow[] result = dataCustomerAndVehicle.Select(query);
这相当于
select * from dataCustomerAndVehicle where CustomerName LIKE '%...%' AND ...