table "demand"

+--------------+------------+---------------+------+-------+--------+---------+
| sku          | isbn       | wob_inv_total | 0to7 | 7to30 | 30to90 | 90to180 |
+--------------+------------+---------------+------+-------+--------+---------+
| GOR000000539 | 0582039193 |             1 | NULL |  NULL |   NULL |    NULL |
| GOR000000677 | 0746026781 |            11 | NULL |  NULL |   NULL |    NULL |
| GOR000000680 | 1841462306 |           108 | NULL |  NULL |   NULL |    NULL |
| GOR000001420 | 1904095968 |             9 | NULL |  NULL |   NULL |    NULL |
| GOR000001571 | 0718115813 |            14 | NULL |  NULL |   NULL |    NULL |
| GOR000003438 | 0903505223 |            33 | NULL |  NULL |   NULL |    NULL |
| GOR000009710 | 1841461121 |            13 | NULL |  NULL |   NULL |    NULL |
| GOR000010354 | 1841468029 |             1 | NULL |  NULL |   NULL |    NULL |
| GOR000011826 | 0746000545 |            32 | NULL |  NULL |   NULL |    NULL |
| GOR000012642 | 0600343340 |           177 | NULL |  NULL |   NULL |    NULL |


table "inv"

+--------------+------------+------------+
| sku          | isbn       | orderdate  |
+--------------+------------+------------+
| GOR001666796 | 0449220605 | 2011-01-07 |
| GOR001298652 | 0749936339 | 2011-01-07 |
| GOR001730634 | 0723257159 | 2011-01-07 |
| GOR001819692 | 0746098391 | 2011-01-07 |
| GOR002284551 | 1852403594 | 2011-01-07 |
| GOR001699321 | 185240373X | 2011-01-07 |
| GOR001339287 | 1852403721 | 2011-01-07 |
| GOR001508750 | 0140264051 | 2011-01-07 |
| GOR001144508 | 0745009638 | 2011-01-07 |
| GOR001221594 | 0007219733 | 2011-01-07 |

Current sql query

update wob_demand as a left join (select sku , count(*) as cnt from wob_inv where orderdate >= CURDATE()-interval 7 day group by sku) as b on a.sku=b.sku set a.0to7=b.cnt;