Warning: file_get_contents(/data/phpspider/zhask/data//catemap/8/design-patterns/2.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
C# 如何使用OleDbDataAdapter和sql查询更新数据库?_C#_Ado.net - Fatal编程技术网

C# 如何使用OleDbDataAdapter和sql查询更新数据库?

C# 如何使用OleDbDataAdapter和sql查询更新数据库?,c#,ado.net,C#,Ado.net,我有以下代码: OleDbDataAdapter dataAdapter = new OleDbDataAdapter("SELECT col1, col2 " + "FROM tab1", connection); 我想这样做: dataAdapter.UpdateCommand = ne

我有以下代码:

OleDbDataAdapter dataAdapter = new OleDbDataAdapter("SELECT col1, col2 "
                                                  + "FROM tab1", 
                                                    connection);
我想这样做:

dataAdapter.UpdateCommand = new OleDbCommand(
            "UPDATE tab1 SET col1 = col1*2, col2 = 300"
          + "WHERE col1 = 5", connection);
var cmd = new OleDbCommand("UPDATE tab1 SET col1 = col1*2, col2 = 300 WHERE col1 = 5", connection);
cmd.ExecuteNonQuery();
如何做到这一点?

只需像这样使用它:

dataAdapter.UpdateCommand = new OleDbCommand(
            "UPDATE tab1 SET col1 = col1*2, col2 = 300"
          + "WHERE col1 = 5", connection);
var cmd = new OleDbCommand("UPDATE tab1 SET col1 = col1*2, col2 = 300 WHERE col1 = 5", connection);
cmd.ExecuteNonQuery();

您不需要数据适配器。

您面临的问题是什么?我有一个选项:
ExecuteNonQuery:Connection属性尚未初始化。
on
cmd.ExecuteNonQuery()
@William,您传入的连接是否为空?