ORA-00907: missing right parenthesis using count with expression inside it - sql

Question

SELECT Hotel_Name, COUNT(H_CHECK.Hotel_checkIn >= 'JUL-1-2016' AND H_CHECK.Hotel_checkIn <= 'JUL-31-2016') FROM HOTEL, H_CHECK
GROUP BY Hotel_Name
ORA-00907: missing right parenthesis
I have tried putting Parenthesis in many ways, but I couldn't find the solution. I'm using Oracle Application Express 11G.
This is the query:
Display the hotel name that has more than 2 customers checked in on July 2016.

Answer 1

Once you fix your immediate syntax problem, you need proper JOIN syntax.
One way to fix the problem is simply to move the conditions to a WHERE clause, resulting in a query like this:
SELECT Hotel_Name, COUNT(hc.hotel_id)
FROM HOTEL h LEFT JOIN
H_CHECK hc
ON h.hotel_id = hc.hotel_id -- I don't know what the right join condition is
WHERE hc.Hotel_checkIn >= DATE '2016-07-01' AND
hc.Hotel_checkIn <= DATE '2016-07-31'
GROUP BY Hotel_Name;

Answer 2

You cannot count based on condition in Select statement of your sql query.
COUNT (
H_CHECK.Hotel_checkIn >= 'JUL-1-2016'
AND H_CHECK.Hotel_checkIn <= 'JUL-31-2016')
This is wrong. You can do it like>
SELECT Hotel_Name,
COUNT (1)
FROM HOTEL
join H_CHECK
ON H_CHECK.Hotel_checkIn >= 'JUL-1-2016'
AND H_CHECK.Hotel_checkIn <= 'JUL-31-2016'
GROUP BY Hotel_Name
having count(1) > 2;

Answer 3

You're missing the CASE ... END from your conditions inside your count. You're after something like:
SELECT Hotel_Name,
COUNT(case when H_CHECK.Hotel_checkIn >= 'JUL-1-2016'
AND H_CHECK.Hotel_checkIn <= 'JUL-31-2016'
then 1
end)
FROM HOTEL, H_CHECK
GROUP BY Hotel_Name;
However, there are a number of concerns I have regarding your query:
if your hotel_checkin column is of DATE datatype, then you should be comparing it to DATEs not strings. I.e. H_CHECK.Hotel_checkIn >= to_date('07-01-2016', 'mm-dd-yyyy') - this way, you avoid relying on implicit conversion of the string into a date, which relies on your NLS_DATE_FORMAT parameter setting. This could be changed and may cause your query to fail.
FROM HOTEL, H_CHECK Don't use the old-style method of joining; instead, use the ANSI style method: FROM hotel cross join h_check
Did you really mean the join to be a cross join or did you forget to add the join conditions?
You should alias the hotel_name column to aid maintainability.
You should also give your count column a name.
Since you're only counting rows with a checkin between 1st and 31st July 2016, you should move this condition into the where clause (as XING has shown in their answer) *unless* you need to also show hotels that don't have any checkins within that time period.
Your condition assumes that there are no time elements to the hotel_checkin column - ie. everything is set to midnight. If, however, you could have a date with a time, bear in mind that your count will ignore all rows with a checkin date of 31st July 2016 that are after midnight. In which case, your upper bound needs to change to: H_CHECK.Hotel_checkIn < to_date('08-01-2016', 'mm-dd-yyyy')