Essentially, the select statement,
When the select on the field before the as,
Then a terrible problem, I face a select statement after the where deny me the name of the field itself, but recognize the conditions of the alias,
Such as the select a, b, c from adc where a <> 0,
A is A nickname, such implementation can get the desired results,
Select a, b, c from adc where a <> 0, so the results not, [his face] [his face] [and]