Java Operations Database

Reference: https://www.cnblogs.com/centor/p/6142775.html

MySQL Connection driver: Mysql-connector-java-5.1.27.jar

1  PackageSqldemo;2 3 Importjava.sql.Connection;4 ImportJava.sql.DriverManager;5 ImportJava.sql.ResultSet;6 Importjava.sql.SQLException;7 Importjava.sql.Statement;8 9  Public classMain {Ten  One      Public Static voidMain (string[] args) { A         //declaring connection Objects - Connection con; -         //driver name theString Driver = "Com.mysql.jdbc.Driver"; -         //the URL points to the database name you want to access MyData -String url = "Jdbc:mysql://localhost:3306/sqltestdb"; -         //user name when MySQL is configured +String user = "root"; -         //password for MySQL configuration +String password = "123456"; A         //traversing query result sets at         Try { -             //Load Driver - Class.forName (driver); -             //1.getConnection () method, connect MySQL database!!  -Con =drivermanager.getconnection (Url,user,password); -             if(!con.isclosed ()) inSYSTEM.OUT.PRINTLN ("Succeeded connecting to the database!"); -             //2. Create the statement class object to execute the SQL statement!!  toStatement Statement =con.createstatement (); +             //the SQL statement to execute -String sql = "SELECT * from emp"; the             //3.ResultSet class, used to store the obtained result set!!   ResultSet rs = statement.executequery (sql);  $System.out.println ("-----------------");Panax NotoginsengSystem.out.println ("The execution results are as follows:");  -System.out.println ("-----------------");  theSystem.out.println ("name" + "\ T" + "title");  +System.out.println ("-----------------");  A               theString job =NULL; +String ID =NULL; -              while(Rs.next ()) { $                 //get stuname This column of data $Job = rs.getstring ("Job"); -                 //get stuid This column of data -id = rs.getstring ("ename"); the  -                 //Output ResultsWuyiSystem.out.println (id + "\ T" +job); the             } - rs.close (); Wu con.close ();//close Connection -}Catch(ClassNotFoundException e) { About             //database-driven class exception handling $System.out.println ("Sorry,can ' t find the driver!");  - E.printstacktrace ();  -}Catch(SQLException e) { -             //database connection failure exception handling A E.printstacktrace ();  +}Catch(Exception e) { the             //Todo:handle Exception - e.printstacktrace (); $}finally{ theSYSTEM.OUT.PRINTLN ("Database data successfully obtained!! "); the         } the     } the  -}

String name;  String ID; PreparedStatement Psql; ResultSet Res;//preprocessing adds data, which has two parameters--"? "Psql = Con.preparestatement ("INSERT into EMP (empno,ename,job,hiredate,sal)" + "VALUES (?,?,?,?,?)");p Sql.setint (1, 3212);//Set parameter 1 to create data with ID 3212Psql.setstring (2, "Wang Gang");//Set parameter 2,name to Wang gangPsql.setstring (3, "President"); DateFormat DATEFORMAT2=NewSimpleDateFormat ("Yyyy-mm-dd");D ate myDate2= Dateformat2.parse ("2010-09-13"));p sql.setdate (4,Newjava.sql.Date (Mydate2.gettime ()));p Sql.setfloat (5, (float) 2000.3);           psql.executeupdate ();  // perform updates
Psql.close;

PreparedStatement psql; // preprocess Update (Modify) data, change the Wang Gang's sal to 5000.0psql = con.preparestatement ("update emp set sal =?"). where ename =? " );p sql.setfloat (1, (float) 5000.0);      Psql.setstring (2, "Wang Gang");             Psql.executeupdate ();
Psql.close ();

PreparedStatement psql; // preprocessing Delete data psql = con.preparestatement ("Delete from emp where Sal >?") );p sql.setfloat (1, 4500);p sql.executeupdate (); psql.close (); 

Java Operations Database