查看“针对customers表的查询操作举例”的源代码

https://www.bilibili.com/video/BV1eJ411c7rf?p=17
{| class="wikitable"
|+Java与SQL对应数据类型转换表
!Java 类型
!SQL 类型
|-
|boolean
|BIT
|-
|byte
|TINYINT
|-
|short
|SMALLINT
|-
|int
|INTEGER
|-
|long
|BIGINT
|-
|String
|CHAR, VARCHAR, LONGVARCHAR
|-
|byte array
|BINARY,，VAR BINARY
|-
|java.sql.Date
|DATE
|-
|java.sql.Time
|TIME
|-
|java.sql.Timestamp
|TIMESTAMP
|}
<syntaxhighlight lang="java">
import io.github.jihch.bean.Customer;
import io.github.jihch.util.JDBCUtils;
import org.junit.Test;

import java.sql.*;

/**
 * 针对于 Customers 表的查询操作
 */
public class CustomerForQuery {

    @Test
    public void testQuery1() {

        String sql = "select id, name, email, birth from customers where id = ?";
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet resultSet = null;

        try {
            conn = JDBCUtils.getConnection();

            ps = conn.prepareStatement(sql);
            ps.setObject(1, 2);

            //执行，并返回结果集
            resultSet = ps.executeQuery();

            //处理结果集
            if (resultSet.next()) { //next():判断结果集的下一条是否有数据，如果有数据返回 true，并指针下移；如果返回 false，指针不会下移

                //获取当前这条数据的各个字段值
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String email = resultSet.getString(3);
                Date birth = resultSet.getDate(4);

                //方式一：
//            System.out.println("id = " + id+", name = " + name + ", email = " + email + ", birth = " + birth);

                //方式二：
//            Object[] data = new Object[]{id, name, email, birth};

                //方式三：将数据封装为一个对象（推荐）
                Customer customer = new Customer(id, name, email, birth);
                System.out.println(customer);

            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            JDBCUtils.closeResource(conn, ps, resultSet);
        }

    }//end testQuery1

}
</syntaxhighlight>https://github.com/jihch/jdbc/blob/main/src/main/java/io/github/jihch/preparedstatement/crud/CustomerForQuery.java