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我有一个像减法在MySQL
Id_indicator Value trend Date_data
1 0 0 2011-08-18 09:16:15
1 2 1 2011-08-18 10:16:15
1 1 -1 2011-08-18 11:16:15
1 2 1 2011-08-18 12:16:15
2 21 0 2011-08-18 13:16:15
2 21 0 2011-08-18 14:16:15
2 21 0 2011-08-18 15:16:15
3 3 0 2011-08-18 16:16:15
3 4 1 2011-08-18 17:16:15
3 4 0 2011-08-18 18:16:15
4 4 0 2011-08-18 19:16:15
我需要找出什么是基于id_indicator先前值之间的差异,在右侧输入该值增加一列的表。例如,作为
Id_indicator Value trend Date_data Difference
1 0 0 2011-08-18 09:16:15 0
1 2 1 2011-08-18 10:16:15 2
1 1 -1 2011-08-18 11:16:15 -1
1 2 1 2011-08-18 12:16:15 1
2 21 0 2011-08-18 13:16:15 0
2 21 0 2011-08-18 14:16:15 0
2 21 0 2011-08-18 15:16:15 0
3 3 0 2011-08-18 16:16:15 0
3 4 1 2011-08-18 17:16:15 1
3 4 0 2011-08-18 18:16:15 0
4 4 0 2011-08-18 19:16:15 0
感谢
的可能的复制[MySQL的 - 从先前行减去值,由基团](http://stackoverflow.com/questions/13196190/mysql-subtracting-value - 从在先排基团的通过) – CGritton