多条件查询

查询学院信息：
public ActionResult SelectAcademe()
{
var listAcademe = from tbAcademe in myModel.SYS_Academe
select new
{
id = tbAcademe.AcademeID,
text = tbAcademe.AcademeName
};
return Json(listAcademe, JsonRequestBehavior.AllowGet);
}
查询年级信息：
public ActionResult SelectGradeByAcademeID(int AcademeID)
{
var list = from tbGrade in myModel.SYS_Grade
where tbGrade.AcademeID == AcademeID
select new
{
id = tbGrade.GradeID,
text = tbGrade.GradeName
};
return Json(list, JsonRequestBehavior.AllowGet);
}
查询班级信息：
public ActionResult SelectClassByGradeID(int GradeID)
{
var listClass = (from tbClass in myModel.SYS_Class
where tbClass.GradeID == GradeID
select new
{
id = tbClass.ClassID,
text = tbClass.ClassName
}).ToList();
return Json(listClass, JsonRequestBehavior.AllowGet);
}
在视图里将在控制器中查询到的学院、年级、班级分别绑定在响应的下拉框中
$("#sltAcademe").change(function () {
var AcademeID = $("#sltAcademe").val();
$("#sltGrade").empty();
$("#sltClass").empty();
appendOption(“sltGrade”, “SelectGradeByAcademeID?AcademeID=” + AcademeID);
});
$("#sltGrade").change(function () {
var GradeID = $(this).val();
appendOption(“sltClass”, “SelectClassByGradeID?GradeID=” + GradeID);
});
function appendOption(id,url) {
$.getJSON(url, function (data) {
$("#"+id).empty();
$("#" + id).append(’----请选择----’);
$.each(data, function (i) {
var str =’’+data[i].text+’’;
$("#"+id).append(str);
});
});
}
他的效果图为：

public ActionResult SelectStudentInfor(LayuiTablePage layuiTablePage,int AcademeID,int GradeID,int ClassID,string StudentNum)
{
var listStudent = (from tbStudent in myModel.PW_Student
join tbAcademe in myModel.SYS_Academe on tbStudent.AcademeID equals tbAcademe.AcademeID
join tbSpecialty in myModel.SYS_Specialty on tbStudent.SpecialtyID equals tbSpecialty.SpecialtyID
join tbGrade in myModel.SYS_Grade on tbStudent.GradeID equals tbGrade.GradeID
join tbClass in myModel.SYS_Class on tbStudent.ClassID equals tbClass.ClassID
join tbUser in myModel.PW_User on tbStudent.UserID equals tbUser.UserID
where tbUser.ToVoidNo == true
select new StudentInfor
{
studentID = tbStudent.studentID,
StudentNumber = tbStudent.StudentNumber,
StudentName = tbStudent.StudentName,
StudentIDNum = tbStudent.StudentIDNum,
StudentSex = tbStudent.StudentSex,
Academe = tbAcademe.AcademeName,
Specialty = tbSpecialty.SpecialtyName,
Grade = tbGrade.GradeName,
Class = tbClass.ClassName,
UserNuber = tbUser.UserNuber,
AcademeID = tbStudent.AcademeID,
GradeID = tbStudent.GradeID,
ClassID = tbStudent.ClassID
}).ToList();
if (AcademeID>0)
{
listStudent = listStudent.Where(m => m.AcademeID == AcademeID).ToList();
}
if (GradeID > 0)
{
listStudent = listStudent.Where(m => m.GradeID == GradeID).ToList();
}
if (ClassID > 0)
{
listStudent = listStudent.Where(m => m.ClassID == ClassID).ToList();
}
if (!string.IsNullOrEmpty(StudentNum))
{
listStudent = listStudent.Where(m => m.StudentNumber.Contains(StudentNum.Trim())).ToList();
}
int totalRows = listStudent.Count();
List list = listStudent.OrderBy(m => m.studentID)
.Skip(layuiTablePage.GetStartIndex()).Take(layuiTablePage.limit).ToList();
LayuiTableData layuiTableData = new LayuiTableData();
layuiTableData.count = totalRows;
layuiTableData.data = list;
return Json(layuiTableData, JsonRequestBehavior.AllowGet);
}
只有中间的if语句才是条件查询，其他的是查询信息