如何在 OracleCommand INSERT INTO 之后检索 sys_guid() 的值

Posted 2023-04-12

【中文标题】如何在 OracleCommand INSERT INTO 之后检索 sys_guid() 的值

【英文标题】：How can you retrieve the value of sys_guid() after an OracleCommand INSERT INTO

【发布时间】：2020-05-16 21:00:32

【问题描述】：

我想在事务中检索包含 Oracle db 生成的 sys_guid() 的特定列的值。

public string GetGUID(OracleConnection connection) 
 
  string guid = "";
  connection.Open();
  OracleCommand cmd = new OracleCommand();
  OracleTransaction transaction;
  transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted);
  cmd.Transaction = transaction;
  cmd.Connection = connection;
  try
  
   cmd = connection.CreateCommand();
   cmd.CommandText = "INSERT INTO CUSTOMERS (NAME,DETAILS) VALUES (:nm, :dts)";
   cmd.Parameters.Add("nm", OracleDbType.VarChar);
   cmd.Parameters["nm"].Value = name;
   cmd.Parameters.Add("dts", OracleDbType.VarChar);
   cmd.Parameters["dts"].Value = details;
   cmd.Prepare();
   OracleDataReader reader = cmd.ExecuteReader();
   while (reader.Read())
   

   
   reader.Close();
   transaction.Commit();
  
  catch (Exception e)
  
      transaction.Rollback();
      Console.WriteLine(e.Message);
      
 return guid;

表 CUSTOMERS 有一个列 ORDER，它使用 SYS_GUID() 创建一个 guid，我如何检索该 guid？

【问题讨论】：

"INSERT INTO CUSTOMERS (NAME,DETAILS) VALUES (:nm, :dts) RETURNING \"ORDER\" INTO :orderid "

侧节点：你没有什么可看的，这就是为什么cmd.ExecuteNonQuery();

抱歉误导 :orderid，我更正了。我没有在 order 列中插入任何值，我使用 sys_guid() 离开 Oracle 数据库来填充它。

sqlines.com/oracle-to-sql-server-cs-conversion/…

【参考方案1】：

试试returning .. into clause 例如

   ...

   using (OracleCommand cmd = connection.CreateCommand()) 
     cmd.CommandText = 
       @"INSERT INTO CUSTOMERS (
           NAME,
           DETAILS) 
         VALUES (
           :nm, 
           :dts)
         RETURNING 
           ""ORDER"" INTO :orderid";

     cmd.Parameters.Add("nm", OracleDbType.VarChar);
     cmd.Parameters["nm"].Value = name;
     cmd.Parameters.Add("dts", OracleDbType.VarChar);
     cmd.Parameters["dts"].Value = details;

     cmd.Parameters.Add("orderid", OracleDbType.VarChar);  
     cmd.Parameters["orderid"].Direction = ParameterDirection.Output;

     try 
       cmd.ExecuteNonQuery(); // Just execute, nothing to read
       transaction.Commit(); 

       guid = Convert.ToString(cmd.Parameters["orderid"].Value);
     
     catch (Exception e)  //TODO: put more specific exception type
       transaction.Rollback();   
       Console.WriteLine(e.Message);     
      

     return guid;
     

   ...

【讨论】：

工作得很好，我使用查询“插入客户（名称，详细信息）值（：nm，：dts）返回订单到：orderid”没有@前缀。非常感谢！