00311_ Preprocessing Object Executeupdate method (implement database increment, delete, change)

1. Overview

(1) The execution of the recorded Insert\update\delete statement is accomplished by preprocessing the Executeupdate method of the object;

(2) The operation format is unified as follows:

① Registration Drive;

② get the connection;

③ gets the preprocessing object;

The ④sql statement placeholder sets the actual parameters;

⑤ Execute SQL statement;

⑥ release resources.

2, insert the RECORD: INSERT, implement to insert the specified new classification into the classification table

1 Importjava.sql.Connection;2 ImportJava.sql.DriverManager;3 Importjava.sql.PreparedStatement;4 5  Public classDemo01 {6      Public Static voidMain (string[] args)throwsException {7         //1 Registration Drive8Class.forName ("Com.mysql.jdbc.Driver");9         //2 Getting the connectionTenConnection conn =Drivermanager.getconnection ( One"Jdbc:mysql://localhost:3306/mybase", "root", "root"); A         //3 getting preprocessed objects -String sql = "INSERT into sort (sname) values (?)"; -PreparedStatement stat =conn.preparestatement (SQL); the         //4 SQL statement placeholder set actual parameters -Stat.setstring (1, "Air conditioning"); -         //5 Execute SQL statement -         intline =stat.executeupdate (); +System.out.println ("Number of newly added records:" +Line ); -         //6 Releasing Resources + stat.close (); A conn.close (); at  -     } -}

Operation Result:

　　

　　

3. Update record: Update, implement the classification name of the record corresponding to the category ID specified in the classification table.

1 Importjava.sql.Connection;2 ImportJava.sql.DriverManager;3 Importjava.sql.PreparedStatement;4 5  Public classDemo02 {6      Public Static voidMain (string[] args)throwsException {7         //1 Registration Drive8Class.forName ("Com.mysql.jdbc.Driver");9         //2 Getting the connectionTenConnection conn =Drivermanager.getconnection ( One"Jdbc:mysql://localhost:3306/mybase", "root", "root"); A         //3 Getting the preprocessed object -String sql = "Update sort set sname=?" where sid=? "; -PreparedStatement stat =conn.preparestatement (SQL); the         //4 SQL statement placeholder set actual parameters -Stat.setstring (1, "digital products"); -Stat.setint (2, 1);//the back of this 1 refers to the SID -         //5 Execute SQL statement +         intline =stat.executeupdate (); -System.out.println ("Number of update records:" +Line ); +         //6 Releasing Resources A stat.close (); at conn.close (); -  -     } -}

Operation Result: "Home appliance" updated to "digital product"

　　

4, delete records: Delete, implementation of the deletion of the classification table in the specified category ID records

1 Importjava.sql.Connection;2 ImportJava.sql.DriverManager;3 Importjava.sql.PreparedStatement;4 5  Public classDemo03 {6      Public Static voidMain (string[] args)throwsException {7         //1 Registration Drive8Class.forName ("Com.mysql.jdbc.Driver");9         //2 Getting the connectionTenConnection conn =Drivermanager.getconnection ( One"Jdbc:mysql://localhost:3306/mybase", "root", "root"); A         //3 getting preprocessed objects -String sql = "Delete from sort where sid=?"; -PreparedStatement stat =conn.preparestatement (SQL); the         //4 SQL statement placeholder set actual parameters -Stat.setint (1, 1); -         //5 Execute SQL statement -         intline =stat.executeupdate (); +System.out.println ("Number of deleted records:" +Line ); -         //6 Releasing Resources + stat.close (); A conn.close (); at  -     } -}

Operation Result: The product of Sid 1 was deleted

　　

　　　　

00311_ Preprocessing Object Executeupdate method (implement database increment, delete, change)