将数据插入.dbf文件时收到错误

时间：2017-03-23 21:09:56

标签： c# database dbf oledbconnection

Backgournd

我目前正在开发一个项目，需要我创建一个本地.dbf文件，然后我必须填充一个值。我目前能够在测试目录中创建一个.dbf文件并为其添加一列，但是当我稍后尝试向该列添加一个值时，它会出错。

问题

我目前无法写入我创建的Public文件中的列.dbf。当代码进入ExecuteNonQuery();时，它会出错，并在我的catch语句中被捕获。

工作代码 

public static bool CreateDBF()
{
    try
    {
        string dbfDirectory = @"c:\Users\me\Desktop\New911";
        string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {
            connection.Open();
            OleDbCommand command = connection.CreateCommand();
            command.CommandText = "create table CustomProperties(Public C(60))";
            command.ExecuteNonQuery();
            connection.Close();
            InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
        }
        return true;
    }
    catch (Exception ex)
    {
        throw;
    }
}

工作代码 - 附录：

上面的代码块成功创建了.dbf文件，其中包含我想要的列，如下图所示

enter image description here

无效代码： 

public static bool InsertDataIntoDBF(string path)
{
    try
    {
        string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
        string query = @"INSERT INTO CustomProperties (Public)";

        using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
        {                    
            OleDbCommand command = new OleDbCommand(query, connection);
            command.Parameters.AddWithValue("@Public", "True");

            connection.Open();

            new OleDbCommand("set null off", connection).ExecuteNonQuery();

            command.ExecuteNonQuery();
            connection.Close();
        }

        return true;
    }
    catch (Exception ex)
    {
        throw;
    }
}

更新了代码块

工作区：

public static bool CreateDBF()
{
  try
  {
    string dbfDirectory = @"c:\Users\er4505\Desktop\New911";
    string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;

    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
      connection.Open();
      OleDbCommand command = connection.CreateCommand();
      command.CommandText = "create table CustomProperties(Public C(60))";
      command.ExecuteNonQuery();
      connection.Close();
    }

    InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
    return true;
  }
  catch (Exception ex)
  {
    string viewError = JsonConvert.SerializeObject(ex);
    return false; << I have a breakpoint here 
  }
}

非工作区块：

public static bool InsertDataIntoDBF(string path)
{
  try
  {
    string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
    string query = @"INSERT INTO CustomProperties (Public) VALUES (@Public)";
    using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
    {                    
      OleDbCommand command = new OleDbCommand(query, connection);
      command.Parameters.AddWithValue("@Public", "True");
      connection.Open();
      command.ExecuteNonQuery();
      connection.Close();
    }
    return true;
  }
  catch (Exception ex)
  {
    string viewError = JsonConvert.SerializeObject(ex);
    return false; << breakpoint here 
  }
}

发现错误：

  

oledbErrors
  消息：语法错误。
  NativeError：0
  来源：Visual FoxPro的Microsoft OLE DB提供程序

     

ClassName：System.Data.OleDb.OleDbException
  消息：语法错误。

3 个答案:

答案 0 :(得分：1)

这对我有用。试试吧

    static void Main(string[] args)
    {
        try
        {
            CreateDBF();
            Console.WriteLine(ReadDB());
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

    private static string dbfDirectory = @"c:\Test\dbTest";
    private static string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dbfDirectory + ";Extended Properties = dBase IV";
    public static bool CreateDBF()
    {            
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {
            connection.Open();
            OleDbCommand command = connection.CreateCommand();
            command.CommandText = "Create Table CustomProperties ([Public] char(50))";
            command.ExecuteNonQuery();
            connection.Close();
        }
        InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
        return true;
    }

    public static bool InsertDataIntoDBF(string path)
    {
        string query = @"INSERT INTO CustomProperties ([Public]) VALUES (@Public)";
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {
            OleDbCommand command = new OleDbCommand(query, connection);
            command.Parameters.AddWithValue("@Public", "True");
            connection.Open();
            command.ExecuteNonQuery();
            connection.Close();
        }
        return true;
    }

    public static string ReadDB()
    {
        string res = string.Empty;
        string query = @"SELECT * FROM CustomProperties";
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {
            OleDbCommand command = new OleDbCommand(query, connection);
            command.Parameters.AddWithValue("@Public", "True");
            connection.Open();
            res = (string)command.ExecuteScalar();
            connection.Close();
        }
        return res;
    }

答案 1 :(得分：0)

错误纯粹是语法，我在以下链接中找到了一个非常好的例子

https://social.msdn.microsoft.com/Forums/en-US/24eac4c5-3a4d-43f4-8607-ef684919c4af/command-contains-unrecognized-phrasekeyword-vbnet?forum=visualfoxprogeneral

工作代码块 

public static bool CreateDBF()
{
  try
  {
    string dbfDirectory = @"c:\Users\er4505\Desktop\New911";
    string connectionString = "Provider=VFPOLEDB;Data Source=" + dbfDirectory;
    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
      connection.Open();
      OleDbCommand command = connection.CreateCommand();
      command.CommandText = "create table CustomProperties(Public C(60))";
      command.ExecuteNonQuery();
      connection.Close();
    }
    InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF");
    return true;
  }
  catch (Exception ex)
  {
    string viewError = JsonConvert.SerializeObject(ex);
    return false;
  }
}

public static bool InsertDataIntoDBF(string path)
{
  try
  {
    string strLogConnectionString = "Provider=VFPOLEDB;Data Source=" + path + ";Collating Sequence=machine;Mode=ReadWrite;";
    string query = "INSERT INTO CustomProperties(Public) VALUES (?)";
    using (OleDbConnection connection = new OleDbConnection(strLogConnectionString))
    {
      connection.Open();
      OleDbCommand cmdInit = new OleDbCommand("set null off", connection);
      cmdInit.ExecuteNonQuery();
      OleDbCommand command = new OleDbCommand(query, connection);
      OleDbParameter publicStatus = command.Parameters.Add("Public", OleDbType.Char);
      publicStatus.Value = "True";
      command.ExecuteNonQuery();
      connection.Close();
    }
    return true;
  }
  catch (Exception ex)
  {
     log4net.LogManager.GetLogger("EmailLogger").Error(JsonConvert.SerializeObject(ex));
            string viewError = JsonConvert.SerializeObject(ex);
            return false;
        }
    }

答案 2 :(得分：-1)

public static bool CreateDBF()
{
   ...
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {
            ...                
        }
        InsertDataIntoDBF(dbfDirectory + "\\CustomProperties.DBF"); // change 1
        return true;
    }
    catch (Exception)
    {
        throw; //change2
    }
}

public static bool InsertDataIntoDBF(string path)
{
    try
    {
        ...       
    }
    catch (Exception)
    {
        throw; //change 3
    }
}
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