我使用 jqGrid，Greg 的示例对我帮助很大。但是我有一个问题我无法解决：
我的 Linq 语句使用连接从三个表中收集数据：
var queryDetails = (from survey in pagedQuery
join subproj in db.t_onlinesubproject
on survey.SubPid equals subproj.datsubprojectid
join proj in db.t_onlineproject
on subproj.datprojectid equals proj.datprojectid
select new
{
survey.scriptID,
proj.projectnumber,
proj.projecttitlesap,
subproj.subprojectname,
survey.Projectname,
survey.platform,
survey.Status,
survey.Programmer
}).ToList();
每当我尝试按其他字段而不是从表调查中搜索或排序时，我都会得到一个 EntitySqlException，例如 projectnumber 不是当前加载模式的元素。
当我从主表（scriptID、Projectname、platform、Status、Programmer）中搜索或订购字段时，一切正常，
projectnumber、projecttitlesap 和 subprojectname 导致上述错误。
任何想法？
这里是我来源的重要部分：
查看：
$(function () {
$("#grid").jqGrid({
url: '@Url.Action("Projects", "Json")',
datatype: 'json',
mtype: 'POST',
colNames: ['id', 'Project number', 'Project title', 'Subproject title', 'Scripters Project title', 'Platform', 'Status', 'Scripter'],
colModel: [
{ name: 'scriptID', index: 'scriptID', width: 20, align: 'right', sorttype: 'int' },
{ name: 'projectnumber', index: 'projectnumber', width: 70, align: 'right' },
{ name: 'projecttitlesap', index: 'projecttitlesap', width: 150, align: 'left' },
{ name: 'subprojectname', index: 'subprojectname', width: 150, align: 'left' },
{ name: 'Projectname', index: 'Projectname', width: 150, align: 'left' },
{ name: 'platform', index: 'platform', width: 8, align: 'center', stype: 'select', surl: '@Url.Action("platformSelect", "Json")', searchoptions: { sopt: ['eq']} },
{ name: 'Status', index: 'Status', width: 60, align: 'left', stype: 'select', surl: '@Url.Action("statusSelect", "Json")', searchoptions: { sopt: ['eq']} },
{ name: 'Programmer', index: 'Programmer', width: 100, align: 'left', stype: 'select', surl: '@Url.Action("scripterSelect", "Json")', searchoptions: { sopt: ['eq']} },
],
pager: jQuery('#pager'),
rowNum: 50,
height: 500,
autowidth: true,
rowList: [5, 10, 20, 50, 100, 200],
ignoreCase: true,
viewrecords: true,
imgpath: '@Url.Content("~/Content/themes/sunny/images")',
caption: 'Projects',
hidegrid: false,
sortable: true,
sortname: $.cookie("grid_index_name") ? $.cookie("grid_index_name") : "scriptID",
sortorder: $.cookie("grid_sort_order") ? $.cookie("grid_sort_order") : "desc",
toolbar: [false, "top"]
});
控制器：
public JsonResult Projects(string sidx, string sord, int page, int rows, bool _search, string filters)
{
var serializer = new JavaScriptSerializer();
Filters f = (!_search || string.IsNullOrEmpty(filters)) ? null : serializer.Deserialize<Filters>(filters);
ObjectQuery<t_scripting> filteredQuery = (f == null ? db.t_scripting : f.FilterObjectSet(db.t_scripting));
filteredQuery.MergeOption = MergeOption.NoTracking; // we don't want to update the data
var totalRecords = filteredQuery.Count();
var pagedQuery = filteredQuery.Skip("it." + sidx + " " + sord, "@skip", new ObjectParameter("skip", (page - 1) * rows)).Top("@limit", new ObjectParameter("limit", rows));
// to be able to use ToString() below which is NOT exist in the LINQ to Entity
var queryDetails = (from survey in pagedQuery
join subproj in db.t_onlinesubproject on survey.SubPid equals subproj.datsubprojectid
join proj in db.t_onlineproject on subproj.datprojectid equals proj.datprojectid
select new
{
survey.scriptID,
proj.projectnumber,
proj.projecttitlesap,
subproj.subprojectname,
survey.Projectname,
survey.platform,
survey.Status,
survey.Programmer
}).ToList();
var jsonData = new
{
total = (totalRecords + rows - 1) / rows,
page,
records = totalRecords,
rows =
(from survey in queryDetails
select new
{
id = survey.scriptID,
cell = new string[] {
survey.scriptID.ToString(),
survey.projectnumber,
survey.projecttitlesap,
survey.subprojectname,
survey.Projectname,
survey.platform != null ? (from p in platforms where (p.id == survey.platform) select p.abbreviation).Single() : String.Empty,
survey.Status != null ? (from s in stati where s.id == survey.Status select s.status).Single() : String.Empty,
survey.Programmer != null ? (from p in programmerAndCommissioner where p.id == survey.Programmer select p.forename + " " + p.surname).Single() : String.Empty
}
}).ToArray()
};
return Json(jsonData, JsonRequestBehavior.AllowGet);
}
帮手：
public class Filters
{
public enum GroupOp
{
AND,
OR
}
public enum Operations
{
eq, // "equal"
ne, // "not equal"
lt, // "less"
le, // "less or equal"
gt, // "greater"
ge, // "greater or equal"
bw, // "begins with"
bn, // "does not begin with"
//in, // "in"
//ni, // "not in"
ew, // "ends with"
en, // "does not end with"
cn, // "contains"
nc // "does not contain"
}
public class Rule
{
public string field { get; set; }
public Operations op { get; set; }
public string data { get; set; }
}
public GroupOp groupOp { get; set; }
public List<Rule> rules { get; set; }
private static readonly string[] FormatMapping = {
"(it.{0} = @p{1})", // "eq" - equal
"(it.{0} <> @p{1})", // "ne" - not equal
"(it.{0} < @p{1})", // "lt" - less than
"(it.{0} <= @p{1})", // "le" - less than or equal to
"(it.{0} > @p{1})", // "gt" - greater than
"(it.{0} >= @p{1})", // "ge" - greater than or equal to
"(it.{0} LIKE (@p{1}+'%'))", // "bw" - begins with
"(it.{0} NOT LIKE (@p{1}+'%'))", // "bn" - does not begin with
"(it.{0} LIKE ('%'+@p{1}))", // "ew" - ends with
"(it.{0} NOT LIKE ('%'+@p{1}))", // "en" - does not end with
"(it.{0} LIKE ('%'+@p{1}+'%'))", // "cn" - contains
"(it.{0} NOT LIKE ('%'+@p{1}+'%'))" //" nc" - does not contain
};
internal ObjectQuery<T> FilterObjectSet<T>(ObjectQuery<T> inputQuery) where T : class
{
if (rules.Count <= 0) return inputQuery;
var sb = new StringBuilder();
var objParams = new List<ObjectParameter>(rules.Count);
foreach (Rule rule in rules)
{
PropertyInfo propertyInfo = typeof(T).GetProperty(rule.field);
if (propertyInfo == null) continue; // skip wrong entries
if (sb.Length != 0) sb.Append(groupOp);
var iParam = objParams.Count;
sb.AppendFormat(FormatMapping[(int)rule.op], rule.field, iParam);
ObjectParameter param;
//nullable workaround
string type = "";
if (propertyInfo.PropertyType.FullName.StartsWith("System.Nullable"))
{
Match m = Regex.Match(propertyInfo.PropertyType.FullName, @"\[\[(.+?),");
if (m.Groups.Count < 2) type = propertyInfo.PropertyType.FullName;
type = m.Groups[1].ToString();
}
else type = propertyInfo.PropertyType.FullName;
//end nullable workaround
//switch (propertyInfo.PropertyType.FullName)
switch (type)
{
case "System.Int32": // int
param = new ObjectParameter("p" + iParam, Int32.Parse(rule.data));
break;
case "System.Int64": // bigint
param = new ObjectParameter("p" + iParam, Int64.Parse(rule.data));
break;
case "System.Int16": // smallint
param = new ObjectParameter("p" + iParam, Int16.Parse(rule.data));
break;
case "System.SByte": // tinyint
param = new ObjectParameter("p" + iParam, SByte.Parse(rule.data));
break;
case "System.Single": // Edm.Single, in SQL: float
param = new ObjectParameter("p" + iParam, Single.Parse(rule.data));
break;
case "System.Double": // float(53), double precision
param = new ObjectParameter("p" + iParam, Double.Parse(rule.data));
break;
case "System.Boolean": // Edm.Boolean, in SQL: bit
param = new ObjectParameter("p" + iParam,
String.Compare(rule.data, "1", StringComparison.Ordinal) == 0 ||
String.Compare(rule.data, "yes", StringComparison.OrdinalIgnoreCase) == 0 ||
String.Compare(rule.data, "true", StringComparison.OrdinalIgnoreCase) == 0 ?
true :
false);
break;
default:
// TO DO: Extend to other data types
// binary, date, datetimeoffset,
// decimal, numeric,
// money, smallmoney
// and so on
param = new ObjectParameter("p" + iParam, rule.data);
break;
}
objParams.Add(param);
}
ObjectQuery<T> filteredQuery = inputQuery.Where(sb.ToString());
foreach (var objParam in objParams)
filteredQuery.Parameters.Add(objParam);
return filteredQuery;
}
}