Java Mysql 简明教程
Java & MySQL - Select Database Example
此章节提供了一个有关如何使用 JDBC 应用选择数据库的示例。在执行以下示例之前,请确保您已经准备就绪:
This chapter provides an example on how to select a Database using JDBC application. Before executing the following example, make sure you have the following in place −
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To execute the following example you need to replace the username and password with your actual user name and password.
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Your MySQL database you are using, is up and running.
Required Steps
创建新的数据库使用 JDBC 应用程序需要执行以下步骤:
The following steps are required to create a new Database using JDBC application −
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Import the packages − Requires that you include the packages containing the JDBC classes needed for the database programming. Most often, using import java.sql.* will suffice.
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Open a connection − Requires using the DriverManager.getConnection() method to create a Connection object, which represents a physical connection with a selected database.
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Selection of database is made while you prepare database URL. Following example would make connection with STUDENTS database.
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Clean up the environment − try with resources automatically closes the resources.
Sample Code
复制并粘贴以下示例到 JDBCExample.java 中,并按照以下方式编译和运行:
Copy and paste the following example in JDBCExample.java, compile and run as follows −
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCExample {
static final String DB_URL = "jdbc:mysql://localhost/TUTORIALSPOINT";
static final String USER = "guest";
static final String PASS = "guest123";
public static void main(String[] args) {
System.out.println("Connecting to a selected database...");
// Open a connection
try(Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);) {
System.out.println("Connected database successfully...");
} catch (SQLException e) {
e.printStackTrace();
}
}
}
现在让我们如下编译上述示例:
Now let us compile the above example as follows −
C:\>javac JDBCExample.java
C:\>
运行 JDBCExample 时,将产生以下结果:
When you run JDBCExample, it produces the following result −
C:\>java JDBCExample
Connecting to a selected database...
Connected database successfully...
C:\>