20150222-linq to SQL Insert, update, and delete

Note that when you use LINQ to SQL, you must have a primary key in the table to work, or the system will not be able to make modifications to the data

Insert new Data and add a new control to it based on the previous piece of the article instance:

Number TextBox (Name): Sno

Name textbox (name): sname

Gender textbox (Name): Ssex

Birthday DateTimePicker (Name): Bir

Class TextBox (Name): Sclass

and add buttons

Here is the code in the Add button:

Private voidTianjia_click (Objectsender, EventArgs e) {            stringSno = Bianhao. Text.trim ();//number textbox            stringsname = Mingzi. Text.trim ();//name textbox            stringSsex = Xingbie. Text.trim ();//sex textboxDateTime bir = Shengri. Value;//Birthday            stringSclass = Banji. Text.trim ();//class TextBox            if(Sno! =""|| Sname! =""|| Ssex! =""|| Sclass! ="") {dataclasses1datacontext DC=NewDataclasses1datacontext (); //initializes the class of this table based on the table name of the table to which you want to add informationStudent stu =NewStudent {Sno=Sno, Sname=sname, Ssex=Ssex, Sbirthday=Bir, Class=Sclass,}; //The following two lines of code are important code to modify the database, can not be omitted, otherwise you will not be able to modify the datadc. Student.insertonsubmit (Stu);//modifying in-memory datadc. SubmitChanges ();//writes the modified data to the database. MessageBox.Show ("Add success! "); }            Else{MessageBox.Show ("please fill in the complete information"); }        }

Attempt to add new data (note that when using LINQ to SQL, a primary key must be available in the table to be effective or the system will not be able to modify the data)

The results of the query again:

Update (Modify) data :

First modify the properties of the GridView, to facilitate our operation, the behavior of the value of SelectionMode to Fullrowselect, select a row

Then add a new event in the GridView (double-click on the right side of DoubleClick):

To add a new control to a form:
Number TextBox (Name): Xiugai_bianhao; fixed number, change its properties--behavior-enabled to False

Name textbox (name): Xiugai_mingzi

Gender textbox (Name): Xiugai_xingbie

Birthday DateTimePicker (Name): Xiugai_shengri

Class TextBox (Name): Xiugai_banji

and Modify Buttons

Then write the following code in the newly created double-click event:

Private voidDatagridview1_doubleclick (Objectsender, EventArgs e) {            //the code here simply writes the selected information to the modified groupXiugai_bianhao. Text = datagridview1.selectedcells[0]. Value.tostring (). Trim ();//numberingXiugai_mingzi. Text = datagridview1.selectedcells[1]. Value.tostring (). Trim ();//nameXiugai_xingbie. Text = datagridview1.selectedcells[2]. Value.tostring (). Trim ();//SexXiugai_shengri. Value =datetime.parse (datagridview1.selectedcells[3]. Value.tostring ());//BirthdayXiugai_banji. Text = datagridview1.selectedcells[4]. Value.tostring (). Trim ();//class}

Note: Query the cells in the selected row, whose cells are indexed from left to right, 0,1,2,3, ...

Modify button:

Private voidButton3_Click (Objectsender, EventArgs e) {Dataclasses1datacontext DC=NewDataclasses1datacontext (); varXiu = DC. Student.single (m = M.sno = = Xiugai_bianhao. Text);//determine the row according to the numberXiu. Sname= Xiugai_mingzi. Text.trim ();//Modify NameXiu. Ssex = Xiugai_xingbie. Text.trim ();//SexXiu. Sbirthday = Xiugai_shengri. Value;//BirthdayXiu. Class = Xiugai_banji. Text.trim ();//classDC. SubmitChanges ();//important code Don't miss out        }

Double-click a row:

Then modify the data in a group that modifies the data:

Click Edit to search again.

The modification was successful.

Delete data:

Add Delete button to write code:

 private  void  button4_click (object   sender, EventArgs e) {  dataclasses1datacontext DC  = new   Dataclasses1datacontext ();  var  del = DC. Student.single (m = M.sno = = Datagridview1.selectedcells[0 ]. Value); //  DC. Student.deleteonsubmit (DEL); //  DELETE statement   DC. SubmitChanges ();  //  important code do not omit  

        }

Select a row and click the Delete button to query again:

Delete succeeded.

20150222-linq to SQL Insert, update, and delete