mysql關聯修改SQL及long與datetime類型相互轉換

1.關聯修改

#解決思路  UPDATE tb1,tb2 SET tb1.address=tb2.address WHERE tb1.name=tb2.name
UPDATE car c,tmpcolorcode t SET c.color_code=t.color_code WHERE c.reg_no=t.reg_no;

2.long與datetime類型相互轉換

#時間datetime轉換為long格式
SELECT UNIX_TIMESTAMP(NOW());  #1410403824

#時間long轉換為datetime格式
SELECT FROM_UNIXTIME(1410403824);  #2014-09-11 10:50:24

3.在實際的處理過程中，需要除以1000

SELECT id,mobile,CODE,FROM_UNIXTIME(create_time/1000) AS createTime,TYPE FROM `mobile_code` ORDER BY id DESC; 

 4.Java代碼：

public static void main(String[] args) {
        Date d = new Date();
        System.out.println("long型數據: " + d.getTime());
        System.out.println("sys型數據: " + System.currentTimeMillis());
    }

long型數據: 1410404639799
sys型數據: 1410404639799

SELECT FROM_UNIXTIME(1410404639799/1000);