作者fantasywater (prepare myself)
看板Database
标题[SQL ] 请问如何相减再 group 起来?
时间Thu Sep 10 06:09:56 2015
+-------+-------+--------+---------+
| att1 | att2 | in/our | time |
+-------+-------+--------+---------+
| A | B | in | 7:00 |
+-------+-------+--------+---------+
| C | D | out | 7:50 |
+-------+-------+--------+---------+
| A | B | out | 7:20 |
+-------+-------+--------+---------+
| C | D | in | 7:10 |
+-------+-------+--------+---------+
请问如何下 SQL 计算时间差再 group 起来呢..?
结果希望像下面这样..苦手中..
+-------+-------+-------------------+
| att1 | att2 | time_diff |
+-------+-------+-------------------+
| A | B | 10 |
+-------+-------+-------------------+
| C | D | 40 |
+-------+-------+-------------------+
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1F：→ elfstart: 第一列算出来是10?还是20 09/10 23:24