Java connection MySQL database three ways

Haven't updated the blog for a long time! Today, using day, I learned a bit about MySQL database. Introduction to the database of three ways to connect!

Development tools: MyEclipse

MySQL5.6

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

Load driver:

1. Create the Lib folder in the project catalog and place the downloaded JDBC in the folder as shown in:

2. Right-click the project name, select Add JARs in the Libraries page in Java build path ..., select the JDBC you just added, such as:

You can also "right-click" in the Project and select "Build Path".

Packet Preparation:

In the database DAY17 create the following data table EMP:

CREATE TABLE EMP (   empno            INT(4)          PRIMARYKEY,   ename             varchar($),   job              varchar(9),   HireDate         DATE,   sal              FLOAT(7,2));

Add Data:

Connect to the database and read the data:

Database name: DAY17

Packet Name: EMP

Port number: 3306

User name: Root

Password: root

1  PackageGz.itcast.a_jdbc;2 3 Importjava.sql.Connection;4 ImportJava.sql.Driver;5 ImportJava.sql.DriverManager;6 Importjava.util.Properties;7 8 Importorg.junit.Test;9 /**Ten * JDBC Connection database One  * @authorAPPle A  * -  */ -  Public classDemo1 { the     //URL of the connection database -     PrivateString url = "Jdbc:mysql://localhost:3306/day17"; -                         //JDBC Protocol: Database sub-protocol: Host: Port/Connected Database// -  +     PrivateString user = "root";//User name -     PrivateString password = "root";//Password +      A     /** at * First Method -      * @throwsException -      */ - @Test -      Public voidTest1 ()throwsexception{ -         //1. Creating a Driver class object inDriver Driver =NewCom.mysql.jdbc.Driver ();//New version -         //Driver Driver = new Org.gjt.mm.mysql.Driver ();//older versions to          +         //set user name and password -Properties props =NewProperties (); theProps.setproperty ("User", user); *Props.setproperty ("Password", password); $         Panax Notoginseng         //2. Connect to the database and return to the Connection object -Connection conn =driver.connect (URL, props); the          + SYSTEM.OUT.PRINTLN (conn); A     } the      +     /** - * Use the Driver Manager class to connect to the database (registered two times, not necessary) $      * @throwsException $      */ - @Test -      Public voidTest2 ()throwsexception{ theDriver Driver =Newcom.mysql.jdbc.Driver (); -         //Driver driver2 = new Com.oracle.jdbc.Driver ();Wuyi         //1. Registering a driver (multiple drivers can be registered) the drivermanager.registerdriver (driver); -         //Drivermanager.registerdriver (driver2); Wu          -         //2. Connect to a specific database AboutConnection conn =drivermanager.getconnection (URL, user, password); $ SYSTEM.OUT.PRINTLN (conn); -          -     } -      A     /** + * (This is the recommended way to connect to the database) the * It is recommended to use the load driver class to register the driver -      * @throwsException $      */ the @Test the      Public voidTest3 ()throwsexception{ the         //Driver Driver = new Com.mysql.jdbc.Driver (); the          -         //registers a driver by loading a static block of code by getting a byte-code object inClass.forName ("Com.mysql.jdbc.Driver"); the          the         //Driver driver2 = new Com.oracle.jdbc.Driver (); About         //1. Registering a driver (multiple drivers can be registered) the         //drivermanager.registerdriver (driver); the         //Drivermanager.registerdriver (driver2); the          +         //2. Connect to a specific database -Connection conn =drivermanager.getconnection (URL, user, password); the SYSTEM.OUT.PRINTLN (conn);Bayi          the     } the  -}

The result of the operation is:

Java connection MySQL database three ways