Java_JDBC一般写法

JDBC是Java DataBase Connectivity,Java程序访问数据库的标准接口。

如果是maven工程先加入依赖的jar包：

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.35</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.35</version>
</dependency>

Statement

String url = "jdbc:mysql://localhost:3306/test_db";
String userName = "root";
String password = "123";
try(Connection conn = DriverManager.getConnection(url, userName,password)) {
    try(Statment sm = conn.createStatement()) {
    String name = "小明";
        try (ResultSet sm = ps.excuteQuery("SELECT * FROM test_table WHERE name='"+  +"'")) {
            while (rs.next()) {
                System.out.println(rs.getString("name"));
            }
        }
    }
}

---

PreparedStatement

1.查询

String url = "jdbc:mysql://localhost:3306/test_db";
String userName = "root";
String password = "123";
try(Connection conn = DriverManager.getConnection(url, userName,password)) {
    try(PreparedStatment ps = conn.preparedStatement("SELECT * FROM test_table WHERE name=?")) {
        ps.setObject(1, "rick");
        try (ResultSet rs = ps.excuteQuery()) {
            while (rs.next()) {
                System.out.println(rs.getString("name"));
            }
        }
    }
}

2.新增、更新、删除

String url = "jdbc:mysql://localhost:3306/test_db";
String userName = "root";
String password = "123";
try(Connection conn = DriverManager.getConnection(url, userName,password)) {
    try(PreparedStatment ps = conn.preparedStatement("UPDATE test_table SET age = ? WHERE name=?")) {
        ps.setObject(2, "rick");
        ps.setInt(1, 18);
        int n = ps.excuteQuery(); //成功执行的数据条数
    }
}