I have a large database and i'd like to pull info from a table (Term) where the Names are not linked to a PartyId for a certain SearchId. However:
There are multiple versions of the searches (sometimes 20-40 - otherwise I think SQL - Comparing two rows and two columns would work for me)
The PartyId will almost always be NULL for the first version for the search, and if the same Name for the same SearchId has a PartyId associated in a later version the NULL row should not appear in the results of the query.
I have 8 left joins to display the information requested - 3 of them are joined on the Term table
A very simplified sample of data is below
CASE statement? Join the table with itself for comparison? A temp table or do I just return the fields I'm joining on and/or want to display?
Providing sample data that yields no expected result is not as useful as providing data that gives an expected result..
When asking a question start with defining the problem in plain English. If you can't you don't understand your problem well enough yet. Then define the tables which are involved in the problem (including the columns) and sample data; the SQL you've tried, and what you're expected result is using the data in your sample. Without this minimum information we make many guesses and even with that information we may have to make assumptions; but without a minimum verifiable example showing illustrating your question, helping is problematic.
--End soap box
I'm guessing you're after only the names for a searchID which has a NULL partyID for the highest SearchVerID
So if we eliminated ID 6 from your example data, then 'Bob' would be returned
If we added ID 9 to your sample data for name 'Harry' with a searchID of 2 and a searchVerID of 3 and a null partyID then 'Harry' too would be returned...
If my understanding is correct, then perhaps...
WITH CTE AS (
SELECT Name, Row_Number() over (partition by Name order by SearchVersID Desc)
FROM Term
WHERE SearchID = 2)
SELECT Name
FROM CTE
WHERE RN = 1
and partyID is null;
This assigns a row number (RN) to each name starting at 1 and increasing by one for each entry; for searchID's of 2. The highest searchversion will always have a RN of 1. Then we filter to include only those RN which are 1 and have a null partyID. This would result in only those names having a searchID of 2 the highest search version and a NULL partyID
Ok So I took the question a different way too..
If you simply want all the names not linked to a PartyID for a given search.
SELECT A.*
FROM TERM A
WHERE NOT EXISTS (SELECT 1
FROM TERM B
WHERE A.Name = B.Name
AND SearchID = 2) and partyID is not null)
AND searchID = 2
The above should return all term records associated to searchID 2
that have a partyId. This last method is the exists not exists and set logic I was talking about in comments.
Related
I have a subject table that has subject_id column. In the table I have one row that has subject_id null other than that subject_id has a distinct value.
I am looking for single query I can fetch the data on basis of subject_id.
Select * from subject where subject_id = x;
If there is no data found w.r.t x than it should return the row with subject_id = null
In general this is a terrible pattern for tables. NULL as a primary key value is only going to cause you pain and suffering in the long run. Using a NULL-keyed row as a default for when your query matches no other rows will lead to strange behavior somewhere unexpected.
The simplest way would be to simply include the NULL row as the last row of any query and then only fetch the first row. But that only works when your query can only return at most one valid result.
select *
from subject
where subject_id = ? or subject_id is null
order by subject_id asc nulls last
Possibly the biggest problem with a NULL PK for your default/placeholder row in subject is that anywhere else you have a NULL subject_id cannot simply join to that row using x.subject_id = y.subject_id.
If you really need such a row, I suggest using -1 instead of NULL as the "not exists" value. It will make your life much easier across the board, especially if you need to join to it.
I'm having difficulties trying to return some data from a poorly structured one to many table.
I've been provided with a data export where everything from 'Section Codes' onwards (in cat_fullxPath) relates to a 'skillID' in my clients database.
The results previously returned on one line but I've used a split function to break these out (from the cat_fullXPath column). You can see the relevant 'skillID' from my clients DB in the far right column:
From here, there are thousands of records that may have a mixture of these skillIDs (and many others, I've just provided this one example). I want to be able to find the records that match all 4 (or however many match from another example) skillIDs and ONLY those.
For example (I just happen to know this ID gives me the results I want):
SELECT
id
skillID
FROM table1
WHERE skillID IN ( 1004464, 1006543, 1004605, 1006740 )
AND id = 69580;
This returns me:
Note that these are the only columns in that table.
So this is an ID I'd want to return.
These are results I'd not want to return as one of the skillIDs are missing:
I've created a temp table with a count of all the skills for each ID but I'm not sure if I'm going down the right path at this point
I'm pretty sure that there's a simple solution to this, however I'm hitting my head against the wall. Hope someone can help!
EDIT
This might be a clearer example of when there are different groups of skillIds that I need to align. I've partitioned these off by cat_fullxpath to see if this makes things clearer:
In this screenshot, for example I want to find the ids for everything in table1 where skillID IN (1003914,1005354,1004701) then repeat for (1004659,1004492,1004493,1004701). etc
We know that you need exactly 4 skills, so just make a subquery:
select id from
(
SELECT
id
count(skillID) countSkill
FROM table1
WHERE skillID IN ( 1004464, 1006543, 1004605, 1006740 )
group by id;
)
where countSkill = 4;
Could work with sum, instead of count. But instead of filtering by the 4, you filter by 4022352, which is the sum of all skillID.
You can also remove the subquery and use HAVING. But you will obtain worse performance.
SELECT
id
count(skillID) countSkill
FROM table1
WHERE skillID IN ( 1004464, 1006543, 1004605, 1006740 )
group by id
having count(skillID) = 4;
You haven't told us your DBMS. Here is a standard SQL approach:
select id
from table1
group by id
having count(case when skillid = 1004464 then 1 end) > 0
and count(case when skillid = 1006543 then 1 end) > 0
and count(case when skillid = 1004605 then 1 end) > 0
and count(case when skillid = 1006740 then 1 end) > 0
and count(case when skillid not in (1004464, 1006543, 1004605, 1006740) then 1 end) = 0;
Another option is to concatenate all skills and see if the resulting skill list matches the desired skill list. In SQL Server the string aggregation function is STRING_AGG.
select id
from table1
group by id
having string_agg(skillid, ',') within group (order by skillid) in
(
'1004464,1004605,1006543,1006740'
);
You can easily extend the IN clause with other combinations or even get the list from another table. Only make sure the skill IDs in the strings are sorted in order to make the strings comparable ('1004464,1004605,1006543,1006740' <> '1006740,1004464,1004605,1006543').
I have two tables:
And I want to add GTIN from table 2 to table 1 based on brand name. Though I cant use = or like because as you see in highlighted row they are not fully matched.
For example
Second row in table 1, suppose to have first GTIN from table 2 because both are Ziagen 300mg tablet. However all of what I tried failed to match all row correctly.
Postgres has a pg_trgm module described here. Start with a cross join joining both tables and calculate the similarity(t1.brand,t2.brand) function, which returns the real number.
Next filter the results based on some heuristic number. Then narrow down with choosing single best match using row_number() window function.
The results might be not accurate, you could improve it by taking generic similarity into account as well.
with cross_similarity(generic1,brand1,gtin,brand2,generic2,sim) as (
select *, similarity(t1.brand, t2.brand) as sim
from t1,
t2
where similarity(t1.brand, t2.brand) > 0
)
, max_similarity as (
select *,
row_number() over (partition by gtin order by sim desc) as best_match_rank
from cross_similarity
)
select * from max_similarity where best_match_rank =1;
This might be a basic sql questions, however I was curious to know the answer to this.
I need to fetch top one record from the db. Which query would be more efficient, one with where clause or order by?
Example:
Table
Movie
id name isPlaying endDate isDeleted
Above is a versioned table for storing records for movie.
If the endDate is not null and isDeleted = 1 then the record is old and an updated one already exist in this table.
So to fetch the movie "Gladiator" which is currently playing, I can write a query in two ways:
1.
Select m.isPlaying
From Movie m
where m.name=:name (given)
and m.endDate is null and m.isDeleted=0
2. Select TOP 1 m.isPlaying
From Movie m
where m.name=:name (given)
order by m.id desc --- This will always give me the active record (one which is not deleted)
Which query is faster and the correct way to do it?
Update:
id is the only indexed column and id is the unique key. I am expecting the queries to return me only one result.
Update:
Examples:
Movie
id name isPlaying EndDate isDeleted
3 Gladiator 1 03/1/2017 1
4 Gladiator 1 03/1/2017 1
5 Gladiator 0 null 0
I would go with the where clause:
Select m.isPlaying
From Movie m
where m.id = :id and m.endDate is null and m.isDeleted = 0;
This can take advantage of an index on (id, isDeleted, endDate).
Also, the two are not equivalent. The second might return multiple rows when the first returns 1. Or the second might return one row when the first returns none.
The first option might return more than 1 row. Maybe you know it won't because you know what data you have stored but the SQL engine doesn't, and it will affect it's execution plan.
Considering that you only have 1 index and it's on the ID column, the 2nd query should be faster in theory, since it would do an index scan from the highest ID with a predicate for the given name, stopping at the first match.
The first query will do a full table scan while comparing column name, endDate and isDeleted, since it won't stop at the first result that matches.
Posting your execution plans for both queries might enlighten a few loose cables.
I have a single table of activities, some labelled 'Assessment' (type_id of 50) and some 'Counselling' (type_id of 9) with dates of the activities. I need to compare these dates to find how long people wait for counselling after assessment. The table contains rows for many people, and that is the primary key of 'id'. My problem is how to produce a result row with both the assessment details and the counselling details for the same person, so that I can compare the dates. I've tried joining the table to itself, and tried nested subqueries, I just can't fathom it. I'm using Access 2010 btw.
Please forgive my stupidity, but here's an example of joining the table to itself that doesn't work, producing nothing (not surprising):
Table looks like:
ID TYPE_ID ACTIVITY_DATE_TIME
----------------------------------
1 9 20130411
1 v 50 v 20130511
2 9 20130511
3 9 20130511
In the above the last two rows have only had assessment so I want to ignore them, and just work on the situation where there's both assessment and counselling 'type-id'
SELECT
civicrm_activity.id, civicrm_activity.type_id,
civicrm_activity.activity_date_time,
civicrm_activity_1.type_id,
civicrm_activity_1.activity_date_time
FROM
civicrm_activity INNER JOIN civicrm_activity AS civicrm_activity_1
ON civicrm_activity.id = civicrm_activity_1.id
WHERE
civicrm_activity.type_id=9
AND civicrm_activity_1.type_id=50;
I'm actually wondering whether this is in fact not possible to do with SQL? I hope it is possible? Thank you for your patience!
Sounds to me like you only want to get the ID numbers where you have a TYPE_ID entry of both 9 and 50.
SELECT DISTINCT id FROM civicrm_activity WHERE type_id = '9' AND id IN (SELECT id FROM civicrm_activity WHERE type_id = '50');
This will give you a list of id's that has entries with both type_id 9 and 50. With that list you can now go and get the specifics.
Use this SQL for the time of type_id 9
SELECT activity_date_time FROM civicrm_activity WHERE id = 'id_from_last_sql' AND type_id = '9'
Use this SQL for the time of type_id 50
SELECT activity_date_time FROM civicrm_activity WHERE id = 'id_from_last_sql' AND type_id = '50'
Your query looks OK to me, too. The one problem might be that you use only one table alias. I don't know, but perhaps Access treats the table name "specially" such that, in effect, the WHERE clause says
WHERE
civicrm_activity.type_id=9
AND civicrm_activity.type_id=50;
That would certainly explain zero rows returned!
To fix that, use an alias for each table. I suggest shorter ones,
SELECT A.id, A.type_id, A.activity_date_time,
B.type_id, B.activity_date_time
FROM civicrm_activity as A
JOIN civicrm_activity as B
ON A.id = B.id
WHERE A.type_id=9
AND B.type_id=50;