Aggregate Functions - How to handle NULL
2011-06-27 10:38 wildboar 阅读(172) 评论(0) 编辑 收藏 举报
I use the sql scripts above to insert some data into another table, the system show the 'warning' message (inside the red rectangle) to me. I found the 'aggregation function' would eliminate the 'NULL' .
For example:
count(id), the value you will get is 4, but count(createuser), the value you will get is 3
