c# - Powershell Mysql 错误

Question

这段代码是:

$cm = New-Object -TypeName MySql.Data.MySqlClient.MySqlCommand
$sql = "Select * FROM onaylanan Order by onaylanma_id ASC"
$cm.Connection = $Connection
$cm.CommandText = $sql
$dr = $cm.ExecuteReader()

while ($dr.Read())
{
$cm2 = New-Object -TypeName MySql.Data.MySqlClient.MySqlCommand
$sql2 = "Delete FROM onaylanan Where onaylanma_id=4"
$cm2.Connection = $Connection
$cm2.CommandText = $sql2
$dr2 = $cm2.ExecuteNonQuery()
  $dr2.Close();

}
$dr.Close();
$Connection.Close()

这个错误是:

Exception calling "ExecuteNonQuery" with "0" argument(s): "There is already an open DataReader associated with this Connection which must be closed first."

Answer 1

如错误所示，您不能通过同一连接同时执行两个查询。

打开第二个连接(您可以将其命名为 Connection2)并将其分配给 $cm2:

$cm2.Connection = $Connection2