如何使用 JDBC 程序将时间戳值插入数据库?
jdbcjava 8object oriented programmingprogramming
SQL 中的时间戳数据类型类似于 SQL 中的日期类型，两者都存储日:月:年:时:分:秒。此外，时间戳还存储秒的小数部分。
将时间戳插入数据库
PreparedStatement 接口提供了一个名为 setTimestamp() 的方法，该方法接受两个参数:一个整型变量，表示需要存储时间戳的占位符的参数索引;一个长整型变量，表示从纪元时间(标准基准时间，例如 1970 年 1 月 1 日 00:00:00 GMT)到所需时间的毫秒数。
示例
假设数据库中有一个名为 dispatches 的表，其描述如下 −
+------------------+--------------+------+-----+-------------------+ | Field | Type | Null | Key | Default | +------------------+--------------+------+-----+-------------------+ | Product_Name | varchar(100) | YES | | NULL | | Name_Of_Customer | varchar(100) | YES | | NULL | | Time_Of_Dispatch | timestamp | NO | | CURRENT_TIMESTAMP | | Location | varchar(100) | YES | | NULL | +------------------+--------------+------+-----+-------------------+
正如您所看到的，该表包含一个名为 Time_Of_Dispatch 的列，用于存储时间戳值。
我们可以使用 PreparedStatement 接口的 setTimestamp() 方法将时间戳存储到其中，并使用 ResultSet 接口的 getTimestamp() 方法检索它。
以下 JDBC 程序将记录存储到调度表中并检索它们 −
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Timestamp;
public class TimeStampExample {
public static void main(String args[])throws Exception {
//获取连接
String mysqlUrl = "jdbc:mysql://localhost/sampledb";
Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
System.out.println("连接已建立......");
//向表中插入值
String query = "INSERT INTO Dispatches VALUES (?, ?, ?, ?)";
PreparedStatement pstmt = con.prepareStatement(query);
pstmt.setString(1, "KeyBoard");
pstmt.setString(2, "Amith"); pstmt.setTimestamp(3, new Timestamp(1567296000000L));
pstmt.setString(4, "Hyderabad");
pstmt.execute();
pstmt.setString(1, "Earphones");
pstmt.setString(2, "Sumith"); pstmt.setTimestamp(3, new Timestamp(1556668800000L));
pstmt.setString(4, "Vishakhapatnam");
pstmt.execute();
pstmt.setString(1, "Mouse");
pstmt.setString(2, "Sudha"); pstmt.setTimestamp(3, new Timestamp(1551398399000L));
pstmt.setString(4, "Vijayawada");
pstmt.execute();
System.out.println("Records inserted......");
//创建 Statement 对象
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("select * from Dispatches");
//检索值
while(rs.next()) {
System.out.println("Product Name: "+rs.getString("Product_Name"));
System.out.println("Name Of The Customer: "+rs.getString("Name_Of_Customer"));
System.out.println("Time Of Dispatch: "+rs.getTimestamp("Time_Of_Dispatch"));
System.out.println("Location: "+rs.getString("Location"));
System.out.println();
}
}
}
输出
Connection established...... Records inserted...... Product Name: KeyBoard Name Of The Customer: Amith Time Of Dispatch: 2019-09-01 05:30:00.0 Location: Hyderabad Product Name: Earphones Name Of The Customer: Sumith Time Of Dispatch: 2019-05-01 05:30:00.0 Location: Vishakhapatnam Product Name: Mouse Name Of The Customer: Sudha Time Of Dispatch: 2019-03-01 05:29:59.0 Location: Vijayawada
