使用PostgreSQL：如何从db.Query获取行数？

As PostgreSQL connector I import following package:

_ "github.com/lib/pq"

The query I run is:

res, err := db.Query("SELECT id FROM applications WHERE email='" + email + "'")

where email is naturally a string. One way to count the number of rows in res is by following snippet

count:=0
for res.Next() {
  count++
  //some other code
}

but there should be some simpler (and quicker) way. It seems RowsAffected() is not the way to go. So, what is your suggestion?

Use the COUNT function:

"SELECT count(*) FROM applications WHERE email='" + email + "'"