Question

我知道这可能是个愚蠢的问题。但是这个查询不起作用。我搜索解决方案超过1小时。请帮忙

 public static bool ChangeEventStatus(Connector cn, EventData eventData)
    {
        int updatedRows = 0;

        using (OleDbCommand cmd = cn.CreateCommand())
        {
            cmd.CommandText = "Update EventList Set IsProcessed = ? Where EventId = ?";

            cmd.Parameters.Add("IsProcessed", OleDbType.Boolean).Value = true;
            cmd.Parameters.Add("EventId", OleDbType.BigInt).Value = eventData.EventId;


            updatedRows = cmd.ExecuteNonQuery();

        }

        return (updatedRows == 1);
    }

我的代码有什么问题。 ChangeEventStatus 方法返回true，但数据库记录没有变化。

Answer 1

 public static bool ChangeEventStatus(Connector cn, EventData eventData)
 {
        int updatedRows = 0;

         using (OleDbConnection conn = new OleDbConnection(someConnectionString));
        {
             conn.Open();
             using (OleDbCommand cmd = cn.CreateCommand())
             {
                 cmd.CommandText = "Update EventList Set IsProcessed = ? Where EventId = ?";

                 cmd.Parameters.Add("@IsProcessed", OleDbType.Boolean).Value = true;
                 cmd.Parameters.Add("@EventId", OleDbType.BigInt).Value = eventData.EventId;


                 updatedRows = cmd.ExecuteNonQuery();

        }

        return (updatedRows == 1);
    }
}

Answer 2

我发现了问题。感谢大家。我在更新后忘了提交交易

Answer 3

我稍微更改了代码并编写了测试。一切正常。检查：

连接字符串

您是否通过了正确的EventId功能？

[TestClass]
public class UnitTest1
{
  [TestMethod]
  public void TestMethod1()
  {
    Assert.AreEqual(true, ChangeEventStatus(new EventData() {EventId = 3}));
  }

  private static bool ChangeEventStatus(EventData eventData)
  {
      int updatedRows = 0;

      using (var cn = new OleDbConnection("Provider=sqloledb;Data Source=localhost;Initial Catalog=FastExperiments;User Id = sa; Password = pass; "))
      {
        using (OleDbCommand cmd = cn.CreateCommand())
        {
            cn.Open();

            cmd.CommandText = "Update EventList Set IsProcessed = ? Where EventId = ?";

            cmd.Parameters.Add("IsProcessed", OleDbType.Boolean).Value = true;
            cmd.Parameters.Add("EventId", OleDbType.BigInt).Value = eventData.EventId;

            updatedRows = cmd.ExecuteNonQuery();
        }
      }
      return (updatedRows == 1);
  }

  private class EventData
  {
    public int EventId { get; set; }
  }
}

更新SQL命令不会更改数据

3 个答案: