10

我使用 IDataReader 来调用不带参数的存储过程。当参数存在时,我没有找到如何执行此操作的示例。IDataReader 是否处理存储过程的参数?

请举个例子。

4

4 回答 4

8

不是IDataReader处理参数的,而是IDbCommand(使用CreateParameter方法)。ExecuteReader然后,您可以使用该方法获取命令的阅读器。

我整理了一个简单的例子:

private static void ExecuteCommand(IDbConnection conn)
{
    using (IDbCommand cmd = conn.CreateCommand())
    {
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.CommandText = "ProcedureName";
        IDataParameter param = cmd.CreateParameter();
        param.ParameterName = "@parameterName";
        param.Value = "parameter value";
        cmd.Parameters.Add(param);
        using (IDataReader reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                // get data from the reader
            }
        }
    }
}
于 2010-06-01T21:34:34.117 回答
7

如果您使用的是Enterprise Library,那么这种风格很适合您:

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using System.Text;
using Microsoft.Practices.EnterpriseLibrary.Data.Sql;

// ...

SqlDatabase db = new SqlDatabase("YourConnectionString");
DbCommand cmd = db.GetStoredProcCommand("YourProcName");
cmd.Parameters.Add(new SqlParameter("YourParamName", "param value"));

using (IDataReader dr = db.ExecuteReader(cmd))
{
    while (dr.Read())
    {
        // do something with the data
    }
}
于 2010-06-01T22:03:21.963 回答
1

DeriveParameters()一些 .NET 提供程序在命令生成器实现中具有静态方法。如果是这样,您可以使用它来检索参数列表,然后填写值。它提供了一种“发现”信息的好方法:

IDbCommand cmd = conn.CreateCommand();

cmd.CommandText = "SomeProcedure";
cmd.CommandType = CommandType.StoredProcedure;

// to avoid hard coded reference to a specific provider type, get a
// command builder object and use reflection to invoke the derive method
DbCommandBuilder cb = dbfact.CreateCommandBuilder();
MethodInfo mi = cb.GetType().GetMethod( "DeriveParameters", 
                                 BindingFlags.Public | BindingFlags.Static );
mi.Invoke( null, new object[] { cmd } );
// show information about each parameter
foreach ( IDataParameter p in cmd.Parameters )
    Console.WriteLine( "{0}, {1}, {2}", p.ParameterName, 
                       p.DbType.ToString(), p.Direction.ToString() );
IDataParameter prm = (IDataParameter)cmd.Parameters["SomeParam"];
prm.Value = "xyz";
IDataReader rdr = cmd.ExecuteReader();
于 2010-06-01T22:21:26.660 回答
0

下面的示例对我有用(仅传递参数名称。我只对字符串参数进行了尝试)

Using drDataReader As IDataReader = _db.ExecuteReader("usp_get_systemsetting", "ORSIniPath")
  Dim iIndex As Int32
  While (drDataReader.Read())
      iIndex = drDataReader.GetOrdinal("SETTING_CHAR")
      If drDataReader.IsDBNull(iIndex) Then
          g_sORSIniPath = ""
      Else
          g_sORSIniPath = drDataReader.GetString(i)
      End If
  End While
End Using
于 2011-06-02T17:52:26.707 回答