如何解决指定的强制类型转换无效的C＃实体框架
将备份数据库与无效数据库进行比较，尤其是将ID列进行比较。确保它们同时匹配 （浮点数）和可为 （NULL）的能力。
引发异常表示列之一（类型为“ double”）与模型不匹配。
“ mp”表上的ID列是模型中唯一的双列。
解决方法
嗨，我一直在代码中看到这个指定的转换无效，但是当我连接到备份数据库时，我没有收到指定的转换无效的错误。我不确定发生了什么。
同样，此代码可在一个数据库上完美运行，而在另一个数据库上却给我错误。
我的控制器
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Data.Linq.SqlClient;
using System.Text.RegularExpressions;
using MvcPaging;
using lookups.Models;
using lookups.Helpers;
namespace lookups.Controllers
{
public class MPController : Controller
{
// GET: /Lookups/
public LpAppsDataDataContext db = new LpAppsDataDataContext();
public const int DefaultPageSize = 30;
//get MP Data
if (countSpace == 1 && v.Count(char.IsLetter) > 3)
{
if (SqlString.CheckStringForComma(v))
{
mpq = db.mps
.Where(c => c.NAME_LAST.ToLower().Contains(SqlString.GetSplitCommaString(v.ToLower(),0))).OrderBy(c => c.NAME_LAST).ThenBy(f => f.NAME_FIRST);
}
else
{
mpq = db.mps
.Where(c => c.NAME_LAST.ToLower().Contains(SqlString.GetSplitString(v.ToLower(),1)) || c.NAME_LAST.Contains(SqlString.GetSplitString(v.ToLower(),0))).OrderBy(c => c.NAME_LAST).ThenBy(f => f.NAME_FIRST);
}
}
else
{
mpq = db.mps
.Where(c => c.NAME_L
ViewBag.count = mpq.Count();
}
}
else { ViewBag.count = 0; }
@ViewBag.col = "Unclaimed Pensions";
return View(mpq.ToPagedList(currentPageIndex,DefaultPageSize));
}
}
}
我的模特
[global::System.Data.Linq.Mapping.TableAttribute(Name = "dbo.mp")]
public partial class mp
{
private string _COMPANY;
private string _STATE;
private System.Nullable<System.DateTime> _DOPT;
private string _SP_STATE;
private string _PRT_NAME;
private string _NAME_LAST;
private string _NAME_FIRST;
private string _LASTADDRESS;
private System.Nullable<double> _ID;
private System.Nullable<System.DateTime> _DATE;
private string _PLAN_TYPE;
public mp()
{
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_COMPANY",DbType = "NVarChar(255)")]
public string COMPANY
{
get
{
return this._COMPANY;
}
set
{
if ((this._COMPANY != value))
{
this._COMPANY = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_STATE",DbType = "NVarChar(255)")]
public string STATE
{
get
{
return this._STATE;
}
set
{
if ((this._STATE != value))
{
this._STATE = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_DOPT",DbType = "DateTime")]
public System.Nullable<System.DateTime> DOPT
{
get
{
return this._DOPT;
}
set
{
if ((this._DOPT != value))
{
this._DOPT = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_SP_STATE",DbType = "NVarChar(255)")]
public string SP_STATE
{
get
{
return this._SP_STATE;
}
set
{
if ((this._SP_STATE != value))
{
this._SP_STATE = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_PRT_NAME",DbType = "NVarChar(255)")]
public string PRT_NAME
{
get
{
return this._PRT_NAME;
}
set
{
if ((this._PRT_NAME != value))
{
this._PRT_NAME = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_NAME_LAST",DbType = "NVarChar(255)")]
public string NAME_LAST
{
get
{
return this._NAME_LAST;
}
set
{
if ((this._NAME_LAST != value))
{
this._NAME_LAST = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_NAME_FIRST",DbType = "NVarChar(255)")]
public string NAME_FIRST
{
get
{
return this._NAME_FIRST;
}
set
{
if ((this._NAME_FIRST != value))
{
this._NAME_FIRST = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_LASTADDRESS",DbType = "NVarChar(255)")]
public string LASTADDRESS
{
get
{
return this._LASTADDRESS;
}
set
{
if ((this._LASTADDRESS != value))
{
this._LASTADDRESS = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_ID",DbType = "Float")]
public System.Nullable<double> ID
{
get
{
return this._ID;
}
set
{
if ((this._ID != value))
{
this._ID = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_DATE",DbType = "DateTime")]
public System.Nullable<System.DateTime> DATE
{
get
{
return this._DATE;
}
set
{
if ((this._DATE != value))
{
this._DATE = value;
}
}
}
[global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_PLAN_TYPE",DbType = "NVarChar(255)")]
public string PLAN_TYPE
{
get
{
return this._PLAN_TYPE;
}
set
{
if ((this._PLAN_TYPE != value))
{
this._PLAN_TYPE = value;
}
}
}
}
堆栈跟踪
Line 257: @ViewBag.col = "Unclaimed Pensions";
Line 258:
Line 259: return View(mpq.ToPagedList(currentPageIndex,DefaultPageSize));
Line 260: }
Line 261:
Stack Trace:
[InvalidCastException: Specified cast is not valid.]
System.Data.SqlClient.SqlBuffer.get_Double() +51
System.Data.SqlClient.SqlDataReader.GetDouble(Int32 i) +62
Read_mp(ObjectMaterializer`1 ) +2057
System.Data.Linq.SqlClient.ObjectReader`2.MoveNext() +32
System.Collections.Generic.List`1.InsertRange(Int32 index,IEnumerable`1 collection) +392
System.Collections.Generic.List`1.AddRange(IEnumerable`1 collection) +10
MvcPaging.PagedList`1..ctor(IQueryable`1 source,Int32 index,Int32 pageSize,Nullable`1 totalCount) +2014
MvcPaging.PagingExtensions.ToPagedList(IQueryable`1 source,Int32 pageIndex,Int32 pageSize,Nullable`1 totalCount) +134
lookups.Controllers.MPController.Mp(Nullable`1 page,String sortOrder) in
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