linq项目中例子实例
在mvc项目中
var ls = (from i in gt.vendor_login
join j in gt.vendor on i.vendor_id equals j.vendor_id
into AAA
from j in AAA.DefaultIfEmpty()
select new myclass { AA = i.vendor_id, BB = j != null ? j.vendor_name_full : null }).ToList();
ViewBag.abc = ls;
return View();
然后在视图中
var ls = (from i in gt.vendor_login
join j in gt.vendor on i.vendor_id equals j.vendor_id
into AAA
from j in AAA.DefaultIfEmpty()
select new myclass { AA = i.vendor_id, BB = j != null ? j.vendor_name_full : null }).ToList();
ViewBag.abc = ls;
return View();
在三层架构中
public string result()
{
return _access.getDataTable("select * from t_parametersrc").Rows.Count.ToString();
}
public List<Parametersrc> GetTabel()
{
List<Parametersrc> ls = _access.getDataTableForObj<Parametersrc>("select * from t_parametersrc");
return ls;
}
/// <summary>
/// one
/// </summary>
/// <returns></returns>
public List<Model.Type> GetPayMent()
{
var ls = new List<Model.Type>();
Model.Type pe = new Model.Type();
List<Parametersrc> lst = GetTabel();
ls = (from i in lst
where i.ParameterType == "payment"
select new { code = i.ParameterCode, name = i.parameterName }).ToList().ConvertAll<Model.Type>(w=>new Model.Type{code=w.code,name=w.name});
return ls;
}
/// <summary>
/// two
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentTwo()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = (from i in lst
where i.ParameterType == "payment"
//select new { x=i.ParameterCode, y=i.parameterName }).ToList().ConvertAll<Model.Parametersrc>(w => new Model.Parametersrc {ParameterCode=w.x,parameterName=w.y});
select new Parametersrc { ParameterCode = i.ParameterCode, parameterName = i.parameterName }).ToList();//㎝硂琌妓
return ls;
}
/// <summary>
/// three
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentThree()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = (from i in lst
where i.ParameterType == "payment"
select i).ToList();
return ls;
}
/// <summary>
/// four
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentFour()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = lst.ToList();
return ls;
}
/// <summary>
/// five
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentFive()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = lst.Where(p => p.ParameterType.Equals("payment")).Select(p => p).ToList();
return ls;
}
/// <summary>
/// six
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentsix()
{
List<Model.Type> ls = new List<Model.Type>();
var lsls = new List<Parametersrc>();
List<Parametersrc> lst = GetTabel();
lsls = lst.Where(p=>p.parameterName.StartsWith("S")).Where(p=>p.ParameterCode.StartsWith("4")).ToList();
return lsls;
}
/// <summary>
/// seven
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentSeven()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = (from i in lst
where i.ParameterType == "payment"
select new { x = i.ParameterCode, y = i.parameterName }).ToList().ConvertAll<Model.Parametersrc>(w => new Model.Parametersrc { ParameterCode = w.x, parameterName = w.y });
return ls;
}
/// <summary>
/// eight
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentEight()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = (from i in lst
where i.ParameterType == "payment"
select i).ToList();
return ls;
}
/// <summary>
/// nine
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentNine()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = lst.ToList();
return ls;
}
/// <summary>
/// ten
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentTen()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = lst.Where(p => p.ParameterType == "payment").ToList();
return ls;
}
/// <summary>
/// eleven
/// </summary>
/// <returns></returns>
public List<Model.Parametersrc> GetPayMentEleven()
{
var ls = new List<Parametersrc>();
var lst = GetTabel();
ls = ls.Where(p => p.ParameterType == "payment").ToList();
return ls;
}
}
public List<Vendor> GetVendorTabel()
{
List<Vendor> vdls = _access.getDataTableForObj<Vendor>("select * from vendor");
return vdls;
}
public List<VendorLogin> GetVendorLoginTabel()
{
List<VendorLogin> vlls = _access.getDataTableForObj<VendorLogin>("select * from vendor_login");
return vlls;
}
public List<Model.Query.VendorLoginQuery> GetVendorLoginList(string str)
{
int i_str = Convert.ToInt32(str);
var ls = new List<Model.Query.VendorLoginQuery>();
VendorLoginQuery vdlq = new VendorLoginQuery();
List<VendorLogin> lsvdlg = GetVendorLoginTabel();
List<Vendor> lsvd = GetVendorTabel();
ls = (from i in lsvdlg
where i.vendor_id==i_str
orderby i.login_id descending
from j in lsvd
where i.vendor_id==j.vendor_id
select new { i, j }).ToList().ConvertAll<VendorLoginQuery>(w => new VendorLoginQuery { login_id = w.i.login_id, vendor_id = w.i.vendor_id, login_ipfrom = w.i.login_ipfrom, login_createdate = w.i.login_createdate, vendor_name_full = w.j.vendor_name_full }).Skip(10).Take(100).ToList();
return ls;
}
public List<Model.Query.VendorLoginQuery> GetVendorLoginListTwo()
{
var ls = new List<Model.Query.VendorLoginQuery>();
List<VendorLogin> lsvdlg = GetVendorLoginTabel();
List<Vendor> lsvd = GetVendorTabel();
ls = (from i in lsvdlg
join j in lsvd on i.vendor_id equals j.vendor_id
into AAA
from j in AAA.DefaultIfEmpty()
select new VendorLoginQuery {vendor_id = i.vendor_id ,vendor_name_full = j != null ? j.vendor_name_full : null}).ToList();
return ls;
}
