SQL Server和Java之间的时间戳差异 [英] Timestamp discrepancies between SQL server and Java

问题描述

我需要将一个简单的过程从Java代码复制到SQL Server存储过程.它将进入生产中的SQL Azure数据库，但是我正在针对本地SQL Express 12安装对其进行测试.

I need to replicate a simple procedure from Java code to SQL Server stored procedure. It will go into a SQL Azure db in production, but I'm testing it against my local SQL Express 12 install.

此存储过程的一部分是将一些值连接到字符串中.

A part of this stored procedure is to concatenate some values into a string.

这是我的示例Java代码:

This is my example Java code:

import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;

import com.google.common.base.Strings;

public static String concat() {
  //init variables with sample data
  DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss.SSS");
  Timestamp date = new Timestamp(dateFormat.parse("04/04/2014 21:07:13.897").getTime());

  //format variables into 0-filled strings
  String formattedDate = String.format("%011d", date.getTime() / 1000);

  //concat those strings
  String finalString = ... + formattedDate + ...;
  return finalString;    
}

变量:

| date                    | formatted_date |
| ----------------------- | -------------- |
| 2014-04-04 21:07:13.897 | 01396638433    |

这在SQL中是等效的:

This is the equivalent in SQL:

DECLARE @date DATETIME;
DECLARE @formatted_date CHAR(11);
DECLARE @final_string CHAR(22);

--init variables with same data as Java code
SET @date = '2014/04/04 21:07:13.897';

--format variables into 0-filled strings
SET @formatted_date = FORMAT(DATEDIFF(s,'1970-01-01 00:00:00', @date), '00000000000');

--concat those strings
SET @final_string = CONCAT(..., @formatted_date, ...);

变量:

| date                    | formatted_date |
| ----------------------- | -------------- |
| 2014-04-04 21:07:13.897 | 01396645633    |

在检查输出是否相同时，我注意到日期不相同:

While checking if the output was the same I noticed the dates are not the same:

Java output:  01396638433
MSSQL output: 01396645633

我打开了本网站，以了解这种差异是什么意思:

I opened this site to see what this difference meant:

Java:  GMT: Fri, 04 Apr 2014 19:07:13 GMT, Your time zone: 4/4/2014 21:07:13 GMT+2
MSSQL: GMT: Fri, 04 Apr 2014 21:07:13 GMT, Your time zone: 4/4/2014 23:07:13 GMT+2

恰好相差两个小时.

我发现要针对SQL Server运行查询以检查时区设置:

I've found a query to run against SQL Server to check time zone settings:

DECLARE @TZ SMALLINT
SELECT @TZ=DATEPART(TZ, SYSDATETIMEOFFSET())

DECLARE @TimeZone VARCHAR(50)
EXEC MASTER.dbo.xp_regread 'HKEY_LOCAL_MACHINE',
'SYSTEM\CurrentControlSet\Control\TimeZoneInformation',
'TimeZoneKeyName',@TimeZone OUT

SELECT @TimeZone, CAST(@TZ/60 AS VARCHAR(5))+':'+Cast(ABS(@TZ)%60 AS VARCHAR(5));

输出:

| Time zone               | Offset  |
| ----------------------- | ------- |
| W. Europe Standard Time | 2:0     |

我这样检查了JVM时区:

I checked JVM time zone like this:

Calendar now = Calendar.getInstance();
System.out.println(now.getTimeZone());
System.out.println(System.getProperties().get("user.timezone").toString());

输出:

sun.util.calendar.ZoneInfo[id="Europe/Berlin",offset=3600000, dstSavings=3600000,
transitions=143, lastRule=java.util.SimpleTimeZone[id=Europe/Berlin, offset=3600000, 
dstSavings=3600000, startYear=0, startMode=2, startMonth=2, startDay=-1,
startDayOfWeek=1, startTime=3600000, startTimeMode=2, endMode=2, endMonth=9,
endDay=-1, endDayOfWeek=1, endTime=3600000, endTimeMode=2]]
Europe/Berlin

如何在Java和SQL Server之间获得相等的时间戳?

How can I get equal timestamps between Java and SQL Server?

推荐答案

即使Mark Rotteveel和dean给出了启发性的答案，我还是做了以下事情:

Even though Mark Rotteveel and dean gave enlightening answers I ended up doing the following:

在我设置的应用程序初始化方法的开始

at the beginning of my application init method I set

TimeZone.setDefault(TimeZone.getTimeZone("UTC"));

以及所有对SQL的调用

and all SQL calls to

getdate()

已替换为

getutcdate()

谢谢您的时间！

这篇关于SQL Server和Java之间的时间戳差异的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！