MySQL和插入最后一个ID问题仍然

Question

确定后，大量的阅读，并试图我仍然不能似乎得到这个工作：

 OdbcCommand cmd = new OdbcCommand("INSERT INTO User (Email) VALUES ('rusty@msn.com'); SELECT LAST_INSERT_ID();", cn); 

cmd.ExecuteNonQuery(); 
       using (OdbcDataReader reader = cmd.ExecuteReader()) 
       { 

       string theUserId = String.Format("{0}", reader.GetString(0)); 
       Label10.Text = theUserId; 

表：

User 
-------- 
UserID (auto increment, pk) 
Email 

运行在调试模式下我上得到错误这条线，

  using (OdbcDataReader reader = cmd.ExecuteReader()) 

，并

cmd.ExecuteNonQuery(); 

Mysql在这一行上说它的语法错误SELECT LAST_INSERT_ID();"，cn）;但从什么是阅读这是合法的。

确切的错误：

ERROR [42000] [MySQL][ODBC 3.51 Driver][mysqld-5.5.9]You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT LAST_INSERT_ID()' at line 1 

编辑：Justins方法：

using (OdbcConnection connection = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=root; Password=commando;")) 
{ 
    // ODBC command and transaction objects 
    OdbcCommand command = new OdbcCommand(); 
    OdbcTransaction transaction = null; 

    // tell the command to use our connection 
    command.Connection = connection; 

    try 
    { 
     // open the connection 
     connection.Open(); 

     // start the transaction 
     transaction = connection.BeginTransaction(); 

     // Assign transaction object for a pending local transaction. 
     command.Connection = connection; 
     command.Transaction = transaction; 

     // TODO: Build a SQL INSERT statement 
     OdbcCommand cmd = new OdbcCommand("INSERT INTO User (Email, FirstName, SecondName, DOB, Location, Aboutme, username, password) VALUES ('" + TextBox1.Text + "', '" + TextBox2.Text + "', '" + TextBox3.Text + "', '" + TextBox4.Text + "', '" + TextBox5.Text + "', '" + TextBox6.Text + "', '" + TextBox7.Text + "', '" + TextBox8.Text + "')", connection); 

     // run the insert using a non query call 
     command.CommandText = cmd.ToString(); 
     command.ExecuteNonQuery(); 

     /* now we want to make a second call to MYSQL to get the new index 
      value it created for the primary key. This is called using scalar so it will 
      return the value of the SQL statement. We convert that to an int for later use.*/ 
     command.CommandText = "select last_insert_id();"; 
     id = Convert.ToInt32(command.ExecuteScalar()); 

     // the name id doesnt not exist in the current context 

     // Commit the transaction. 
     transaction.Commit(); 
    } 
    catch (Exception ex) 
    { 
     Label10.Text = ": " + ex.Message; 

     try 
     { 
      // Attempt to roll back the transaction. 
      transaction.Rollback(); 
     } 
     catch 
     { 
      // Do nothing here; transaction is not active. 
     } 
    } 
} 

Answer 1

澄清，MySQL的.NET ODBC驱动程序不允许多个命令，就像你所描述的运行。您必须进行两个独立的呼叫并将其包装在交易中。

// open a new connection using a default connection string I have defined elsewhere 
using(OdbcConnection connection = new OdbcConnection(s_connectionString)) 
{ 
     // ODBC command and transaction objects 
     OdbcCommand command = new OdbcCommand(); 
     OdbcTransaction transaction = null; 

     // tell the command to use our connection 
     command.Connection = connection; 

     try 
     { 
      // open the connection 
      connection.Open(); 

      // start the transaction 
      transaction = connection.BeginTransaction(); 

      // Assign transaction object for a pending local transaction. 
      command.Connection = connection; 
      command.Transaction = transaction; 

      // TODO: Build a SQL INSERT statement 
      StringBuilder SQL = new StringBuilder(); 

      // run the insert using a non query call 
      command.CommandText = SQL.ToString(); 
      command.ExecuteNonQuery(); 

      /* now we want to make a second call to MYSQL to get the new index 
       value it created for the primary key. This is called using scalar so it will 
       return the value of the SQL statement. We convert that to an int for later use.*/ 
      command.CommandText = "select last_insert_id();"; 
      id = Convert.ToInt32(command.ExecuteScalar()); 

      // Commit the transaction. 
      transaction.Commit(); 
    } 
    catch(Exception ex) 
    { 
      Debug.WriteLine(ex.Message); 

      try 
      { 
       // Attempt to roll back the transaction. 
       transaction.Rollback(); 
      } 
      catch 
      { 
       // Do nothing here; transaction is not active. 
       } 
     } 
} 

Answer 2

如果你的电子邮件是唯一可以使用

Select ID From User where Email='rusty@msn.com' 

你确信你总是得到正确的答案。

如果你的电子邮件是不是唯一的，你应该使用锁，以确保只有线程执行查询，然后将您的插入后，使用此查询

Select Max(ID) From User 

Answer 3

一种解决方法：

1. 添加out param to your query：
2. 查询内部使用SET @OpParam = SELECT LAST_INSERT_ID（）;
3. 在你的代码中，如果（（int）@ OpParam.Value> 0）{pull out}。
4. 此外，如果运行选择，则改为NonQuery，使用ExecuteScalar（）。

希望它可以帮助你。