I am working on a hotel management software and I need to display floors and the rooms on that floor......
I have a wing_master table in the database with following columns -:
wing_id,
wing_name,
floor,
floor_room_count,
status
Its like I have a record for one wing in that hotel which has 4 floors, but when I write a query to get the floors in that wing it just gives me "4" as the result in sql.....
I want the query to return it as follows -:
1
2
3
4
I want it this way so that I can use nested data-list control in asp.net....
My query is "select floors from wing_master where wing_id = 1"
For most databases (not MySQL), you can use a recursive query to obtain all floors:
with all_floors as (
select floors from wing_master where wing_id = 1
union all
select floors - 1 as floors from all_floors
where floors > 1
)
select * from all_floors order by floors;
SQLFiddle example.
In MySQL, the easiest way would be to create a numbers table that has a sequence of numbers up to the highest possible floor. Then join to that table to get all floors:
select num from wing_master
join numbers on
wing_id = 1 and
num <= floors;
SqlFiddle example.
Your query is ok, and also it seems that query and table structure will be fulfilling your requirements. can you show your data, because as per the structure, there should be four rows in the table, showing floor 1, 2, 3, 4
something like this
floor wing_id
1 1
2 1
3 1
4 1
If that is how your data looks, then your query must be ok, else there is some other issue. so do share your structure with few rows of data.
Related
Suppose I have a database containing two tables, similar to below:
Table 1:
tweet_id tweet
1 Scrap the election results
2 The election was great!
3 Great stuff
Table 2:
politician tweet_id
TRUE 1
FALSE 2
FALSE 3
I'm trying to write a SQL query which returns the percentage of tweets that contain the word 'election' broken down by whether they were a politician or not.
So for instance here, the first 2 tweets in Table 1 contain the word election. By looking at Table 2, you can see that tweet_id 1 was written by a politician, whereas tweet_id 2 was written by a non-politician.
Hence, the result of the SQL query should return 50% for politicians and 50% for non-politicians (i.e. two tweets contained the word 'election', one by a politician and one by a non-politician).
Any ideas how to write this in SQL?
You could do this by creating one subquery to return all election tweets, and one subquery to return all election tweets by politicians, then join.
Here is a sample. Note that you may need to cast the totals to decimals before dividing (depending on which SQL provider you are working in).
select
politician_tweets.total / election_tweets.total
from
(
select
count(tweet) as total
from
table_1
join table_2 on table_1.tweet_id = table_2.tweet_id
where
tweet like '%election%'
) election_tweets
join
(
select
count(tweet) as total
from
table_1
join table_2 on table_1.tweet_id = table_2.tweet_id
where
tweet like '%election%' and
politician = 1
) politician_tweets
on 1 = 1
You can use aggregation like this:
select t2.politician, avg( case when t.tweet like '%election%' then 1.0 else 0 end) as election_ratio
from tweets t join
table2 t2
on t.tweet_id = t2.tweet_id
group by t2.politician;
Here is a db<>fiddle.
I have one table with the following columns and sample values:
[test]
ID | Sample | Org | EmployeeNumber
1 100 6513241
2 200 3216542
3 300 5649841
4 100 9879871
5 200 6546548
6 100 1116594
My example count query based on [test] returns these sample values grouped by Org:
Org | Count of EmployeeNumber
100 3
200 2
300 1
My question is can I use this count to update test.Sample to 'x' for the top 3 records of Org 100, the top 2 records of Org 200, and the top 1 record of Org 300? It does not matter which records are updated, as long as the number of records updated for the Org = the count of EmployeeNumber.
I realize that I could just update all records in this example but I have 175 Orgs and 900,000 records and my real count query includes an iif that only returns a partial count based on other columns.
The db that I am taking over uses a recordset and loop to update. I am trying to write this in one SQL update statement. I have tried several variations of nested select statements but can't quite figure it out. Any help would save my brain from exploding. Thanks!
Assuming, that id is the unique ID of the row, you could use a correlated subquery to select the count of row IDs of the rows sharing the current organization, that are less than or equal to the current row ID and check, that this count is less than or equal to the number of records from that organization you want to designate.
For example to mark 3 records of the organization 100 you could use:
UPDATE test
SET sample = 'x'
WHERE org = 100
AND (SELECT count(*)
FROM test t
WHERE t.org = test.org
AND t.id <= test.id) <= 3;
And analog for the other cases.
(Disclaimer: I don't have access to Access (ha, ha, pun), so I could not test it. But I guess it's basic enough, to work in almost every DBMS, also in Access.)
Say I've got some data from a SELECT query. Can I use this as a table later, meaning naming it something then using its rows and columns in other queries?
I can't solve this problem for the life of me. I'm a beginner. It's just one table but I just can't get a query working. Here is what I have:
Hotel table and Room table (I'll just need to use the Room table; I mentioned Hotel just as a reference point for understanding).
Room has the following columns: (Number,HID) - this is a composite primary key; Number is the numerical number of the room and HID is the ID of the hotel which it belongs to. I also have one more column, Name. Now the problem is:
Find all the Hotels which only have rooms Named OneBedroom
I tried (and failed) by doing it by selecting all HIDs from Room, then filtering on not exist(hotels that have at least one non-OneBedroom named room), but I couldn't make this work.
Room
Number HID Name
1 H1 OneBedroom
2 H2 OneBedroom
3 H1 OneBedroom
4 H1 OneBedroom
5 H2 TwoBedroom
6 H3 OneBedroom
Desired Output: HID
H1
H3
I suspect something like this would do it
SELECT DISTINCT `hid` FROM `room` WHERE
`room`.`hid` NOT IN
(SELECT `hid` as `hid` FROM `room` WHERE `name` != "OneBedroom");
Untested, might be crap, but seems like it should work. Basically, the inner query gets all hid's of rooms that are not OneBedrooms. We then subtract all of those hid's from a full list of hid's.
The easiest way is using group by plus having with a conditional count, so no need to include aditional subquery.
This return hotel with all room = "OneBedroom", remember COUNT only count values <> NNLL
SELECT `hid`
FROM `room`
GROUP BY `hid`
HAVING COUNT(CASE WHEN `name` != "OneBedroom" THEN 1 END ) = 0
At least one bedroom is call "OneBedroom"`
HAVING COUNT(CASE WHEN `name` = "OneBedroom" THEN 1 END ) >= 1
The default value for CASE is NULL so no need for ELSE part
I'm going with a table like this from what you describe:
table Room
HID Number Name
----------------------------------------
1 101 OneBedroom
1 102 OneBedroom
1 103 TwoBedroom
1 201 Suite
2 101 OneBedroom
2 102 OneBedroom
2 103 OneBedroom
which I assume connects to a table Hotel:
table Hotel
HID name
------------------
1 StayOver
2 SleepTite
Now for the query:
SELECT h.name
FROM Hotel h
WHERE h.HID NOT IN (SELECT r.HID
FROM Room r
WHERE name != 'OneBedroom');
which will give you a list of the hotel names with only one bedroom rooms.
Works on SQLite with sample data. Should be okay.
EDIT - based on edited question:
SELECT h.HID . . .
instead of h.name in above query.
I have data in a table like following
Name indicator
A 1
A 2
A 3
B 1
B 2
C 3
I want to get count of Names, for which both indicator 1,2 exists. In the preeceding example, this number is 2 (A & B both have indicator as 1, and 2).
The data I am dealing with is moderately large, and i need to get the similar information of some other permutations of (pre defined ) indicators (which i can change, once i get base query).
Try this:
SELECT Name
FROM Tablename
WHERE indicator IN(1, 2)
GROUP BY Name
HAVING COUNT(DISTINCT indicator) = 2;
See it in action here:
SQL Fiddle Demo
Suppose I have a table that looks like this:
id attribute
1 football
1 NFL
1 ball
2 football
2 autograph
2 nfl
2 blah
2 NFL
I would like to get a list of distinct ids where the attribute column contains the terms "football", "NFL", and "ball". So 1 would be included, but 2 would not. What's the most elegant/efficient way to do this in Terdata?
The number of attributes can vary for each id, and terms can repeat. For example, NFL appears twice for id 2.
You can use the following:
select id
from yourtable
where attribute in ('football', 'NFL', 'ball')
group by id
having count(distinct attribute) = 3
See SQL Fiddle with Demo (fiddle is showing MySQL, but this should work in TeraData)