I have a sqlite database, database_all.
The database_all contains many tables of which some are data_table and some are id_tables.
The data_tables look like this:
index GenderId EducationId
1 1 1
2 2 2
3 2 1
and the id_tables look like this:
dim.Gender:
Id Name
1 F
2 M
dim.Education:
Id Name
1 High
2 Low
Is there a way, to revalue all the columns that contain the string Id (the number of the columns is unknown) with the values that correspond to the specific Id value from the respective id_table ?
The desired output should look like:
index GenderId EducationId
1 F High
2 M Low
3 M High
if i understand correctly, you need to find a way to analyze the queried table structure and automatically link its columns to the corresponding value table, right ?
I think this is not possible without programming so I didn't look into this so much...
but you might find some answers using pragmas.
select x.name, y.name from sqlite_master x, pragma_table_info(x.name) y;
this will dynamically give you the a full tables-to-columns mapping.
hope this helps
Related
I would like to filter data by column Base =1 and then count the number of unique values in another column 'Animal' in SQL, data:
Animal Base Value
1 A 1 X
2 B 1 X
3 A 2 Y
4 A 3 V
Expected output in this case is 2 from the first two rows.
Simpler than you may have thought:
SELECT count(DISTINCT Animal)
FROM tbl
WHERE Base = 1;
Should work in any halfway decent RDBMS including your undisclosed one. (You may have to enclose column names in double-quotes.)
This should do it, assuming the table is named animals:
select count(*) from (select distinct Animal from animals where Base=1) tb1;
Apologies for the horrible question title,not sure how to articulate it better.
So to start out.
**Table Dummy_Table**
id description filter_key
1 Test Record1 filterkey1
2 Test Record2 filterkey1
3 Test Record1 filterkey2
4 Test Record2 filterkey2
The records with filterkey1 map to a table like this
**Table Mapping_table**
Dummy_Table_id someother_key (one(Dummy_Table_id) to many(someother_key)
1 x
1 y
1 z
1 r
2 y
2 r
Now : In a query I map the id's to each other in the Dummy_Table using the description,so I end up with a resultset like this
id_for_filter_key1 id_for_filterkey2
1 3
2 4
Ok,thats all good and well,it's the next step I'm having a issue with.I need to add records to Table Mapping_table which should end up looking like this
**Table Mapping_table**
Dummy_Table_id someother_key
3 x
3 y
3 z
3 r
4 y
4 r
So in essence whatever the id is for filterKey1 I would like to apply it's someother_key to the id's with filterkey2 (filterKey1 and filterkey2 relate to each other with their descriptions)
Now I don't know if I'm over complicating this.I'll tell you what my problem is.
I have records in the database with filterkey1 which map to the mapping table.Afterwords I added the records with filterkey2.These rows are duplicates just with another filter key.Now I need to apply the same mappings to the records with filterkey2
Changing the table structure is not a option atm.I need to give the DBA a insert query to achieve this.
Many thanks in advance.
This query gives missing values:
SELECT d.id_for_filterkey2, m.someother_key
FROM Mapping_table m
JOIN Dummy_Table d ON m.Dummy_Table_id = d.id_for_filter_key1
Demo: http://sqlfiddle.com/#!4/61ddfe/2
When we have missing values, then we can merge them into Mapping_table:
MERGE INTO Mapping_table m
USING( copy-the-above-query-and-paste-it-here) x
ON (x.id_for_filterkey2 = m.Dummy_Table_id)
WHEN NOT MATCHED THEN
INSERT( Dummy_Table_id, someother_key )
VALUES( x.id_for_filterkey2, x.someother_key );
Demo: http://sqlfiddle.com/#!4/d74304/3
I am working on a tag recommendation system that takes metadata strings (e.g. text descriptions) of an object, and splits it into 1-, 2- and 3-grams.
The data for this system is kept in 3 tables:
The "object" table (e.g. what is being described),
The "token" table, filled with all 1-, 2- and 3-grams found (examples below), and
The "mapping" table, which maintains associations between (1) and (2), as well as a frequency count for these occurrences.
I am therefore able to construct a table via a LEFT JOIN, that looks somewhat like this:
SELECT mapping.object_id, mapping.token_id, mapping.freq, token.token_size, token.token
FROM mapping LEFT JOIN
token
ON (mapping.token_id = token.id)
WHERE mapping.object_id = 1;
object_id token_id freq token_size token
+-----------+----------+------+------------+--------------
1 1 1 2 'a big'
1 2 1 1 'a'
1 3 1 1 'big'
1 4 2 3 'a big slice'
1 5 1 1 'slice'
1 6 3 2 'big slice'
Now I'd like to be able to get the relative probability of each term within the context of a single object ID, so that I can sort them by probability, and see which terms are most probably (e.g. ORDER BY rel_prob DESC LIMIT 25)
For each row, I'm envisioning the addition of a column which gives the result of freq/sum of all freqs for that given token_size. In the case of 'a big', for instance, that would be 1/(1+3) = 0.25. For 'a', that's 1/3 = 0.333, etc.
I can't, for the life of me, figure out how to do this. Any help is greatly appreciated!
If I understood your problem, here's the query you need
select
m.object_id, m.token_id, m.freq,
t.token_size, t.token,
cast(m.freq as decimal(29, 10)) / sum(m.freq) over (partition by t.token_size, m.object_id)
from mapping as m
left outer join token on m.token_id = t.id
where m.object_id = 1;
sql fiddle example
hope that helps
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
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.