c# - WCF 和 SQL 错误

Question

我正在构建一个简单的 WCF 服务，该服务必须从 SQL 表返回一些数据。当我运行该项目时，出现以下错误:

Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service

如果我注释所有的 SQL 部分并发送一些静态数据，一切都运行良好。这是让我头疼的功能:

public Client getClient(int idClient)
{
    Client c = new Client();
    SqlConnection sql = new SqlConnection(@"Data Source=GRIGORE\SQLEXPRESS;Initial Catalog=testWCF;Integrated Security=True");
    sql.Open();

    SqlCommand cmd = new SqlCommand("Select * from Clienti where id = " + idClient);
    SqlDataReader dr = cmd.ExecuteReader();
    if (dr.Read())
    {
        c.idClient = int.Parse(dr["id"].ToString());
        c.numeClient = dr["nume"].ToString();
    }

    dr.Close();
    sql.Close();

    return c;
}

想法？

Answer 1

您没有设置 SqlCommand 实例的 Connection 属性。你需要这样做:

    SqlCommand cmd = new SqlCommand("Select * from Clienti where id = " + idClient);
    cmd.Connection = sql;  // added Connection property initialization
    SqlDataReader dr = cmd.ExecuteReader();

或者你可以将它注入(inject)到你的构造函数中:

    SqlCommand cmd = new SqlCommand("...your query text", sql);