Android uses JDBC to connect to a remote database

Android Use Jdbc Connect to remote database

as everyone knows ,Android Is based on Java Compiling , And its core class library also contains most JDK Class library of . So theoretically Java The functions that can be realized are Android It's all possible . This includes calling the server-side database .

Guide pack

stay AS On gradle It can help us easily complete the work of guiding packages . The source of the package can be found in mavan Search the warehouse .

    implementation group: 'mysql', name: 'mysql-connector-java', version: '5.1.42'

Connect to database

First, you need to register the driver class , Usually you only need to register once , But if you need to keep the connection in the background for a long time, it is recommended to register every time you perform the operation

        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            // Registration failed 
            e.printStackTrace();
        }

Next, connect to the remote database , Remember, it's best to do it in the sub thread

Connection conn = DriverManager.getConnection(url, userName, passWord);

Create a declaration object , For operating the database

Statement stmt = conn.createStatement();

perform SQL Modify the statement

String sql = "insert into table ...";
stmt.execute(sql);
stmt.close();
conn.close();

perform SQL Query statement

String sql = "select * from " + tableName;
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
    Person p = new Person(re.getInt(1),re.getString("name"))
}
rs.close();
stmt.close();
conn.close();

summary

The overall use is very simple , It should be noted that there is driver registration , And if that's done SQL You need to release resources after the statement , Next time you connect, you'd better re register the next driver .