Addition, deletion, query and modification of data

Data addition, deletion, query and modification

First instantiation entity model

Inquire about

LINQ Standard query statement

Declare a variable ：var a =from Variable in data source . Specific table

select Variable   Query the data of the whole table

return json（a, JsonRequestBehavior.AllowGet） Return the data

 

newly added

In the page, first give the new button a click event , Define a method to pop up the new modal form , Call this method

example ：

 

Submit the page data to the controller Complete a new operation

First get the data in the form , You can get one by one , You can also serialize forms

serialize

So let's define a variable , adopt ID The selector finds what needs to be serialized from Forms . serializeArray（）;

example ：var dataArr = $("#frm").serializeArray(); Serialize the form as An array

Submit

use post Method

$.post（“URL”, Data submitted ,function（ Receive the data returned by backfilling ）{

alert（）; Pop up the return value

Close modal box ：$（“ Of the modal box ID”）.modal（“hide”）;

Save update page ：window.location.reload(dataArr);

}）;

Method of submitting new data

Define methods

example ：public ActionResult InsertStudent(SYS_Student modStudent）{}（ Receive data through entity class methods ）

Define a variable to store information about the success or failure of the new addition

string str= "";

add to ： Instantiated entity model . Data sheet .Add（）;

example ：myModel.SYS_Student.Add(modStudent);

Data saving operation ： Instantiated entity model . SaveChanges（）;

example ：myModel.SaveChanges() ;

Finally, return the information to

return json（str,JsonRequestBehavior . AllowGet）;

modify

1. Select the data to be modified . Pop up the modified mode box

$（“ Of the modal box ID”）.modal（“show”）;

1. Display the data to be modified in the modal box

Define a method in the controller through ID Find out the data

get data

$.post（URL, Data transferred { attribute ： Property value },function（）{

Data binding

$（ID）.val（）; adopt ID Find and assign

example ：$("#upStudentName").val(data[0].studentName);

}）

1. Modify the save function in the mode box （ Modify the function ）

Define a method in the controller to receive the data transmitted from the page

example ：public ActionResult UpdateStudent(SYS_Student modStudent)

Define a variable to store information about the success or failure of the modification

string str= "";

adopt Entry（） Pass the modified data back . Status code

example ：myModel.Entry(modStudent).State = System.Data.Entity.EntityState.Modified;

Data saving operation ： Instantiated entity model . SaveChanges（）;

example ：myModel.SaveChanges() ;

Finally, return the information to

return json（str,JsonRequestBehavior . AllowGet）;

Define the saving method in the modify mode box in the page

So let's define a variable , adopt ID The selector finds what needs to be serialized from Forms

example ：var arrData = $("#frmModify").serializeArray();

Submit data

use post Method

$.post（“URL”, Data submitted ,function（ Receive the data returned by backfilling ）{

alert（）; Pop up the return value

Close modal box ：$（“ Of the modal box ID”）.modal（“hide”）;

Save update page ：window.location.reload();

}）;

Delete

Write a input label , The type is

Define a method on the page

A query box pops up asking whether to delete data

if (window.confirm(" Delete this data ")) {

Declare a variable to get the of the element value value

use post Method

$.post（“URL”, Data submitted ,function（ Receive the data returned by backfilling ）{

alert（）; Pop up the return value

Save update page ：window.location.reload();

});

Define a method in the controller

example ：public ActionResult DeleteStudent(int studentID)

Define a variable to store information about the success or failure of deletion

string str= "";

according to ID First query out the data to be deleted

The first method ：linq Standard query

example ：

 

The second method ：lamda The method of expression

example ：

 

adopt Remove（） Method to delete the data to be deleted

example ：myModel.SYS_Student.Remove(student);

Data saving operation ： Instantiated entity model . SaveChanges（）;

example ：myModel.SaveChanges() ;

Finally, return the information to

return json（str,JsonRequestBehavior . AllowGet）;