MySQL with a simple JDBC operation

/*
Comparison between statement and PreparedStatement
Each time the SQL statement executes, the database executes the compilation of the SQL statement, preferably in the case where only one query is executed and the result is returned, and there is a SQL injection risk.
PreparedStatement is more efficient than statement when executing a variable-parameter SQL, because it is certainly more efficient for a DBMS to precompile a SQL than to compile a single SQL.
Security is better, effectively prevent SQL injection problem, due to the use of car-cleaning mechanism, pre-compiled statements will be placed in the cache, the next time the same SQL statement, you can directly from the
Cache, which greatly improves the efficiency of execution.
*/
Law One statement use
Public Static voidMain (string[] args) {//Import the driver's jar package first (you can download mysql jdbc driver online), right-click Properties-->java build path-->add external jarsString URL= "Jdbc:mysql://localhost:3306/student";//the URL address of the connection databaseString username= "root";//user name of the databaseString password= "123";//password for the databaseConnection con=NULL; Try        {            //1. Load MySQL Database driverClass.forName ("Com.mysql.jdbc.Driver"); //2. Establish the database connection, connection is the java.sql packagecon=drivermanager.getconnection (URL, username,password); if(con!=NULL) {System.out.println ("Database connection succeeded"); }Else{System.out.println ("Database Connection not successful"); }            //3 Creating SQL statement objectsStatement statement=con.createstatement (); //String sql= "insert into login values (' Xiaoge ', ' female ', ' Shandong ')"; //String sql= "Delete from login where name= ' Jack '";String sql= "Update login set name= ' Lucy ' where city= ' Nanjing '"; //4 EXECUTE Statement            intR=statement.executeupdate (SQL); if(r>0) {                 //System.out.println ("Insert success.."); //System.out.println ("Update success..");System.out.println ("Delete success ..."); }            Else {                //System.out.println ("fail..");            }        }         Catch(Exception e) {e.printstacktrace (); //If an error occurs, print the exception information at the command line where and why the error occurred in the program.         }        finally        {            //5. Releasing Resources            if(con!=NULL) {                Try{con.close (); Con=NULL; }                 Catch(SQLException e) {e.printstacktrace (); }            }        }    }

//Fah PreparedStatement
Public Static voidMain (string[] args) {Try{class.forname ("Com.mysql.jdbc.Driver"); Connection Connection=drivermanager.getconnection ("Jdbc:mysql://localhost:3306/student", "root", "123"); String sqlString= "INSERT into login values (?,?,?)"; PreparedStatement PreparedStatement=connection.preparestatement (sqlString); intrset=preparedstatement.executeupdate (); //small Mark starts at 1//preparedstatement.setstring (1, "Lifang");//preparedstatement.setstring (2, "female");//preparedstatement.setstring (3, "Guangdong");preparedstatement.setstring (1, "Tom"); Preparedstatement.setstring (2, "Man"); Preparedstatement.setstring (3, "Beijing"); intresult=preparedstatement.executeupdate (); if(result>0) {System.out.println ("Insert Success ..."); }            Else{System.out.println ("Insert Fail ..."); }        } Catch(Exception e) {e.printstacktrace (); }    }

MySQL with a simple JDBC operation