How to combine two conditions in a where clause?

问题:

I have the following:

time_range = (1.month.ago.beginning_of_month..1.month.ago.end_of_month)

Comment.where(:created_at => time_range).count

How can I add to the where clause with a statement like:

.where("user_id is not in (?)",[user_ids]).

How can I combine the two? Thanks

回答1:

if you want a "AND" conditional query, try this:

Comment.
  where(:created_at => time_range).
  where("user_id is not in (?)",[user_ids])

which will produce SQL like : select ... where ... AND ...

if you want the WHERE clause more complicated, such as: where ( a AND b) OR (c AND d), you have to combine the conditions into the clause yourself, e.g.

Comment.where("(a AND b ) OR (c AND d)")

回答2:

User.where(["name = ? and email = ?", "Joe", "[e-mail]"])

This will be fine.

回答3:

User.where(name: 'Joe', email: '[e-mail]')