DataTable的一些特殊用法：Select
/**//*
* 補充一下，還可以利用DataView來達到檢索的目的。
*/
DataTable dataSource = new DataTable();
DataView dv = dataSource.DefaultView;
dv.RowFilter = "columnA = 'abc'";
//1.過濾后直接獲取DataTable
DataTable newTable1 = dv.ToTable();
//2.設置新DataTable的TableName
DataTable newTable2 = dv.ToTable("NewTableName");
//3.設置新表是否過濾重復項,擁有的列的列名以及出現的順序
//即可以設置新表的字段。但是字段名肯定是老表dataSource中擁有的。
DataTable newTable3 =
dv.ToTable(true, new string[] 
{ "columnA,columnF,columnC" });
//4.綜合了2.3兩點。
DataTable newTable4 =
dv.ToTable("NewTableName", true, new string[] { "columnA,columnF,columnC" });
簡化，利用 DataView過濾
DataView dv = this.dtPerson.DefaultView; //設置一個視圖過濾
dv.RowFilter = "employee_dept_id = " + departId;
this.lstSource.DataSource = dv;
this.lstSource.DisplayMember = "employee_name";
this.lstSource.ValueMember = "id";
this.dvPendingNode.RowFilter = "(node_end_time is null or node_end_time > '2009-6-10 17:55:13')";
this.dvPendingNode.RowFilter += "and degree_name in ('', '進行', '暫停', '擱置') ";
1. 我在一個winform程序里用DataView的RowFilter篩選時用兩個下劃線代表兩個字符，但是怎么篩選不出來的?
http://topic.csdn.net/t/20040814/04/3273316.html
Q:
我在一個winform程序里用DataView的RowFilter篩選時用兩個下劃線代表兩個個字符，如：
dv.RowFilter="PID LIKE '"+str+"-__"，這樣的篩選語句在SQL企業管理器里執行是能正確篩選到記錄的，但是為什么在這里就一個都篩選不出來？是不是這里要用別的符號來代表一個字符啊。
A:
"_" is probably very sql server specific, classes in System.Data is supposed to be DBMS independent, you can try to use
ABC LIKE 'abc*' AND LEN(ABC)=5
2. ListBox 多項選擇（DataRowView）
for (int i = 0; i < this.lstSource.SelectedItems.Count; i++)
{
DataRowView row = this.lstSource.SelectedItems[i] as DataRowView;
int id = Int32.Parse(row["id"].ToString());
string employee = String.Format("{0}<{1}>", row["employee_name"], row["dept_name"]);
//數據填充
if (!this.idList.Contains(id))
{
this.idList.Add(id);
this.valueList.Add(employee);
}
System.Windows.Forms.ListBox.SelectedIndexCollection indexes = this.lstTarget.SelectedIndices;
for (int i = indexes.Count - 1; i >= 0; i--)
{
this.idList.RemoveAt(indexes[i]);
this.valueList.RemoveAt(indexes[i]);
}
posted on 2010-04-22 12:35
黃小二 閱讀(1656)
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