将数据插入 .dbf 文件时收到错误

Question

背景知识

我目前正在做一个项目，需要我创建一个本地 .dbf 文件，然后我必须在该文件中填充一个值。我目前能够在测试目录中创建一个 .dbf 文件并向其添加一列，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 .dbf 文件中的 Public 列。当代码进入 ExecuteNonQuery(); 时，它出错并被我的 catch 语句捕获。

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包含我想要的列的 .dbf 文件，如下图所示

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;
    }
}

更新代码块

工作块：

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; << I have a breakpoint here 
  }
}

非工作块：

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
Message: Syntax error.
NativeError: 0
Source: Microsoft OLE DB Provider for Visual FoxPro

ClassName: System.Data.OleDb.OleDbException
Message: Syntax error.

Answer 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
    }
}

Answer 2

这对我有用。试一试

    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;
    }

Answer 3

错误纯粹是语法错误，我在以下 link

中找到了一个非常好的示例作为指导

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;
        }
    }

将数据插入 .dbf 文件时收到错误

Receiving an error when insert data into a .dbf file

c#

database

dbf

oledbconnection