零基础掌握JDBC操作MySQL

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="Http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.hsq</groupId>
    <artifactId>jdbc-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
    </dependencies>
</project>

public class DBUtil {
    private static final DataSource dateSource;
    static {
        MysqlDataSource db = new MysqlDataSource();
        db.setServerName("localhost");
        db.setPort(3306);    // MySQL 服务器端口，一般为3306
        db.setUser("root");    // 登录 MySQL 服务器的用户名
        db.setPassword("123456");    // 登录 MySQL 服务器的密码
        db.setDatabaseName("0331_library");    // 设置默认库
        db.setUseSSL(false);
        db.setCharacterEncoding("utf-8"); 
        db.setServerTimezone("Asia/Shanghai");
        dateSource = db;
    }
    public static Connection connection() throws SQLException {
        return dateSource.getConnection();
    }
}

String sql = "要执行的 SQL";
try (Connection c = db.getConnection()) {
    try (PreparedStatement ps = c.prepareStatement(sql)) { 
        try (ResultSet rs = ps.executeQuery()) { 
            while (rs.next()) {
                int i = rs.getInt(1);
                String s = rs.getString(2); 
            }
        }
    }
}

String sql = "不带结果的 SQL";
try (Connection c = db.getConnection()) {
    try (PreparedStatement ps = c.prepareStatement(sql)) {
        ps.executeUpdate();
    }
}

public class Main {
    public static void main(String[] args) throws SQLException {
        MysqlDataSource db = new MysqlDataSource();
        db.setServerName("localhost");
        db.setPort(3306);
        db.setUser("root");
        db.setPassword("123456");
        db.setDatabaseName("0331_library");
        db.setUseSSL(false);
        db.setCharacterEncoding("utf-8");
        db.setServerTimezone("Asia/Shanghai");
     // 增
     try (Connection c = db.getConnection()) {
         String sql = "insert into readers (name) values ('陈浩')";
         try (PreparedStatement ps = c.prepareStatement(sql)) {
             ps.executeUpdate();
         }
     }
    // 删
     try (Connection c = db.getConnection()) {
         String sql = "delete from readers where rid = 1";
         try (PreparedStatement ps = c.prepareStatement(sql)) {
             ps.executeUpdate();
         }
     } 
    // 改
     try (Connection c = db.getConnection()) {
         String sql = "update readers set name = '123' where rid = 1";
         try (PreparedStatement ps = c.prepareStatement(sql)) {
             ps.executeUpdate();
         }
     } 
    // 查
     try (Connection c = db.getConnection()) {
         String sql = "select name from readers where rid = 1";
         try (PreparedStatement ps = c.prepareStatement(sql)) {
             try (ResultSet rs = ps.executeQuery()) {
                where (rs.next) {
                    String name = rs.getString(1);
                }    
             }
         }
     } 
}