我一直在第三次尝试插入下面的代码时收到错误“给出的一个或多个必需参数没有值”。前两次尝试正常工作。我在.NET 4.0中运行,针对VS 2012中的MS Access。而且,无论使用2007 accdb还是2000-2003 mdb,此问题似乎都是一致的。我使用下面的代码来测试:Dapper,MS Access,Integers和“没有给出一个或多个所需参数的值”
using Dapper;
using System.Data.OleDb;
namespace DapperTest {
class Program {
static string accdb = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=W:\Projects\CSharp\DapperTest\DuhData.accdb;";
static string mdb = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=W:\Projects\CSharp\DapperTest\DuhData.mdb";
static void Main(string[] args) {
var dis = new DisMember { FName = "Heza", LName = "Dufus", Initials = "", HighestGrade = 1 };
using (OleDbConnection conn = new OleDbConnection(mdb)) {
try {
conn.Execute("DROP TABLE DisMember;");
}
catch (System.Exception) { }
conn.Execute("CREATE TABLE DisMember ("
+ "FName CHAR, "
+ "Initials CHAR, "
+ "LName CHAR, "
+ "HighestGrade Number "
+ "); "
);
// First attempt: This works in Dapper but does not include HighestGrade
conn.Execute("INSERT INTO DisMember(FName, Initials, LName) "
+ "VALUES (@FName, @Initials, @LName);", dis
);
// Second attempt: This works without Dapper and includes HighestGrade
using (OleDbCommand cmd = conn.CreateCommand()) {
conn.Open();
cmd.CommandText = "INSERT INTO DisMember(FName, Initials, LName, HighestGrade) VALUES (?, ?, ?, ?); ";
cmd.Parameters.AddWithValue("FName", dis.FName);
cmd.Parameters.AddWithValue("Initials", dis.Initials);
cmd.Parameters.AddWithValue("LName", dis.LName);
cmd.Parameters.AddWithValue("HighestGrade", 1);
cmd.ExecuteNonQuery();
}
// Third attempt: This does not work with Dapper because of HighestGrade
conn.Execute("INSERT INTO DisMember(FName, Initials, LName, HighestGrade) "
+ "VALUES (@FName, @Initials, @LName, @HighestGrade);", dis
);
}
}
}
public class DisMember {
public DisMember() { }
public string FName { get; set; }
public string LName { get; set; }
public string Initials { get; set; }
public int HighestGrade { get; set; }
}
}
那么,这是Dapper中的一个错误吗? OLEDB? Access 2013?或者是其他东西?
任何和所有线索非常感谢。
让HighestGrade成为数据库中的一个整数? –
这是一个很好的建议,但这是(最终)反对现有数据。我必须像现在这样处理它。 :) – EDanaII
然后让HighestGrade成为你的类定义中的一个浮点数!或者执行一些转换。 –