in the gorm official document "Model definition" section, the screenshot is shown as follows:
http://gorm.io/zh_CN/docs/mod.
question:
1, Age
field type is sql.NullInt64
, what does this sql.NullInt64
mean? Why should I use the pointer * string
for the types of
2 and MemberNumber
fields? Where does it point?
3, Email
and Role
fields are all of string
type, followed by type:varchar (100)
and size:255
, respectively. Suppose size
is also changed to 100
, then:
type:varchar(100)
size:100
what"s the difference between the two ways of writing?