JDBC连接数据库

Jdbc 连接数据库

1 连接字符串

SQLite

Class.forName("org.sqlite.JDBC"); 
Connection conn =DriverManager.getConnection("jdbc:sqlite:zieckey.db");

MySQL (http://www.mysql.com)

Class.forName( "org.gjt.mm.mysql.Driver" ); 
Connection conn = DriverManager.getConnection( "jdbc:mysql://MyDbComputerNameOrIP:3306/myDatabaseName", sUsr, sPwd );

PostgreSQL (http://www.de.postgresql.org)

Class.forName( "org.postgresql.Driver" ); 
Connection conn = DriverManager.getConnection( "jdbc:postgresql://MyDbComputerNameOrIP/myDatabaseName", sUsr, sPwd );

Oracle (http://www.oracle.com/ip/deploy/database/oracle9i/)

Class.forName( "oracle.jdbc.driver.OracleDriver" ); 
Connection conn = DriverManager.getConnection( "jdbc:oracle:thin:@MyDbComputerNameOrIP:1521:ORCL", sUsr, sPwd );

Microsoft SQLServer (http://jtds.sourceforge.net)

Class.forName( "net.sourceforge.jtds.jdbc.Driver" ); 
cn = DriverManager.getConnection( "jdbc:jtds:sqlserver://MyDbComputerNameOrIP:1433/master", sUsr, sPwd );

Microsoft SQLServer (http://www.microsoft.com)

Class.forName( "com.microsoft.jdbc.sqlserver.SQLServerDriver" ); 
Connection conn = DriverManager.getConnection( "jdbc:microsoft:sqlserver://MyDbComputerNameOrIP:1433;databaseName=master",sUsr, sPwd );

2 释放资源的写法

public class DBUtil {
    public static void close(Connection conn) {
        close(conn, null, null);
    }
    public static void close(Connection conn, Statement stmt, ResultSet resultSet) {
        if (resultSet != null) {
            try {
                resultSet.close();
            } catch (Exception ignored) {}
        }
        if (stmt != null) {
            try {
                stmt.close();
            } catch (Exception ignored) {}
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (Exception ignored) {}
        }
    }
}

3 连接 SQLite3 的示例

public void sqliteJDBCDemo() {
    Connection conn = null;
    try {
        // 1. 驱动
        Class.forName("org.sqlite.JDBC");
        // 2. 打开连接
        conn = DriverManager.getConnection("jdbc:sqlite:e:/data/student.sqlite3");

        // 3. 操作
        Statement statement = conn.createStatement();
        ResultSet resultSet = statement.executeQuery("select name, weixin, score from student");
        while (resultSet.next()) {
            System.out.printf("Name: %s, Weixin: %s, Score: %f
",
                    resultSet.getString(1),
                    resultSet.getString(2),
                    resultSet.getFloat(3));
        }
    } catch (ClassNotFoundException e) {
        System.out.println("1. 驱动加载失败");
    } catch (SQLException e) {
        System.out.println("2. 数据库异常");
    } finally {
        // 4. 释放资源
        if (conn != null)
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
    }
}