MySQL statement exercise

Http://blog.sina.com.cn/s/blog_767d65530101861c.html

http://blog.csdn.net/kaihuishang666/article/details/74407972

http://blog.csdn.net/dehu_zhou/article/details/52881587

Data Type--decimal

The declaration syntax for a column is DECIMAL (m,d).

Ifnull (EXPR1,EXPR2) function

If EXPR1 is not Null,ifnull () returns EXPR1, it returns EXPR2. Ifnull () returns a numeric or string value, depending on the context in which it is used.

MySQL statement exercise