I would like to know if it's possible to search in all vertices by one specifig field value, without naming each vertex explicitly 🤔
If you do not specify the label it is possible to query all nodes via property.
Say I have two labels Actors(properties: ActorId and Name) and Movies(properties: tconst and primaryTitle) in a database called IMDB and I want to search for either movies or actors named Kevin Bacon.
I can query across both node labels. However, if the property names are different this makes little sense and will not utilize the indices.
> GRAPH.QUERY IMDB "MATCH (a{Name: 'Kevin Bacon'}) RETURN a limit 1"
1) 1) 1) "a.ActorId"
2) "a.Name"
3) "a.tconst"
4) "a.primaryTitle"
2) 1) "nm0000102"
2) "Kevin Bacon"
3) "NULL"
4) "NULL"
Related
I'm extracting a table of 2000+ rows which are park details. One of the columns is JSON type. Image of the table
We have about 15 attributes like this and we also have a documentation of pre-determined codes assigned to each attribute.
Each row in the extracted table has a different set of attributes that you can see in the image. Right now, I have cast(parks.services AS text) AS "details" to get all the attributes for a particular park or extract just one of them using the code below:
CASE
WHEN cast(parks.services AS text) LIKE '%uncovered%' THEN '2'
WHEN cast(parks.services AS text) LIKE '%{covered%' THEN '1' END AS "details"
This time around, I need to extract these attributes by assigning them the codes. As an example, let's just say
Park 1 - {covered, handicap_access, elevator} to be {1,3,7}
Park 2 - {uncovered, always_open, handicap_access} to be {2,5,3}
I have thought of using subquery to pre-assign the codes, but I cannot wrap my head around JSON operators - in fact, I don't know how to extract them on 2000+ rows.
It would be helpful if someone could guide me in this topic. Thanks a lot!
You should really think about normalizing your tables. Don't store arrays. You should add a mapping table to map the parks and the attribute codes. This makes everything much easier and more performant.
step-by-step demo:db<>fiddle
SELECT
t.name,
array_agg(c.code ORDER BY elems.index) as codes -- 3
FROM mytable t,
unnest(attributes) WITH ORDINALITY as elems(value, index) -- 1
JOIN codes c ON c.name = elems.value -- 2
GROUP BY t.name
Extract the array elements into one record per element. Add the WITH ORDINALITY to save the original order.
Join your codes on the elements
Create code arrays. To ensure the correct order, you can use the index values created by the WITH ORDINALITY clause.
My model looks like so: Each Bottle has an attribute name, and a relationship to Brand.
In one of my views, I want to show a user all distinct bottles, and their counts.
A distinct bottle is a bottle that has the same name attribute, and the same Brand relationship.
So this table:
Should display 2 lines instead of 3, with the proper quantities (1 for Eitan, 2 for Almon).
The following line in my views.py:
object = Bottle.objects.filter(brand__business__owner_id=user.id).all().values('name').annotate(Count('brand'))
Produces this when I print object:
<QuerySet [{'name': 'Almon', 'brand__count': 2}, {'name': 'Eitan', 'brand__count': 1}]>
Which seems to be the right direction, but it has two problems:
I lose all other fields (vintage, capacity) except name and brand__count. I can of course explicitly add them to values, but that seems a) upythonic b) that it will group_by these items as well!
My pug template complains: Need 2 values to unpack in for loop; got 1 (this is because I'm iterating through them as a list, and using its index for numbering)
Any help is appreciated!
object = Bottle.objects.filter(brand__business__owner_id=user.id).all().values('name','vintage','capacity').annotate(Count('brand'))
unless you mention the fields to filter as you are mentioning name then how will the query set pass it to you? then do this, like not mentioning any name in the values
object = Bottle.objects.filter(brand__business__owner_id=user.id).all().values().annotate(Count('brand'))
both of this will give you all the fields in Bottle table
For example I want to filter my data based on next filter expression:
lead_veh_of_interest starts with 'BMW 1'
OR
sale_model starts with 'BMW 1'
how can I achieve this?
Are these fields both in the same table? If so you could create a calculated column that performs that conditional. Then filter the view on the resulting calculated column.
For example you could create the following calculated column.
Calculated Column: "Starts With BMW 1"
Equation:
=IF(OR(Left([lead_veh_of_interest starts], 5) = "BMW 1", Left([sale_Model], 5) = "BMW 1"), 1, 0)
Then in the view set the filter so that [Starts With BMW 1] = 1
I found acceptable solution (thanks for all suggestions - it was very helpful).
First of all I redesigned my model and (how #Mike_Honey suggsts me) created dedicated table with consolidated information I want to filter. Next I connected this new table with existing tables and created hierarchy from fields I want to give to the end users for step-wise filtering (previously I split down old fields contained information I want to filter into more granular level). Now it is possible to filter data by any combination of models in any combination of request types (sale, lead, competitor, etc) using hierarchy.
I have this query:
SELECT last_name, SCORE(1)
FROM Employees
WHERE CONTAINS(last_name, '%sul%', 1) > 0
It produces output below:
The question is:
Why does the SCORE(1) produce 9? As I recall that CONTAINS function returns number of occurrences of search_string (in this case '%sul%').
I expect the output should be:
Sullivan 1
Sully 1
But when I try this syntax:
SELECT last_name, SCORE(1)
FROM Employees
WHERE CONTAINS(last_name, 'sul', 1) >0;
It returns 0 rows selected.
And can someone please explain me what is the third parameter for?
Thanks in advance :)
The reason your second query is returning no rows is, you are looking for word sul in your search. Contains will not do pattern search unless you tell it to, it searches for words which you specified as your second paramter. To look for patterns, you will have to use wildcards, as you did in your first example.
Now, coming to the third parameter in CONTAINS - it is label and is just used to label the score operator. You should use the third parameter when you use SCORE in your SELECT list. It's importance is more clear when there are multiple SCORE operators
Quoting directly from documentaion
label
Specify a number to identify the score produced by the query.
Use this number to identify the CONTAINS clause which returns this
score.
Example
Single CONTAINS
When the SCORE operator is called (for example, in a SELECT clause),
the CONTAINS clause must reference the score label value as in the
following example:
SELECT SCORE(1), title from newsindex
WHERE CONTAINS(text, 'oracle', 1) > 0 ORDER BY SCORE(1) DESC;
Multiple CONTAINS
Assume that a news database stores and indexes the title and body of
news articles separately. The following query returns all the
documents that include the words Oracle in their title and java in
their body. The articles are sorted by the scores for the first
CONTAINS (Oracle) and then by the scores for the second CONTAINS
(java).
SELECT title, body, SCORE(10), SCORE(20) FROM news WHERE CONTAINS
(news.title, 'Oracle', 10) > 0 OR CONTAINS (news.body, 'java', 20) > 0
ORDER BY SCORE(10), SCORE(20);
The Oracle Text Scoring Algorithm does not score by simply counting the number of occurrences. It uses an inverse frequency algorithm based on Salton's formula.
Inverse frequency scoring assumes that frequently occurring terms in a document set are noise terms, and so these terms are scored lower. For a document to score high, the query term must occur frequently in the document but infrequently in the document set as a whole.
Think of a google search. If you search for the term Oracle you will not find (directly) any result that may help to explain your scoring value questioning, so we can consider this term a "noise" to your expectations. But if you search for the term Oracle Text Scoring Algorithm you will find your answer in the first google result.
And about your other questionings, I think that #Incognito already gives them a good answer.
Use:
The user searches for a partial postcode such as 'RG20' which should then be displayed in a specific order. The query uses the MATCH AGAINST method in boolean mode where an example of the postcode in the database would be 'RG20 7TT' so it is able to find it.
At the same time it also matches against a list of other postcodes which are in it's radius (which is a separate query).
I can't seem to find a way to order by a partial match, e.g.:
ORDER BY FIELD(postcode, 'RG20', 'RG14', 'RG18','RG17','RG28','OX12','OX11')
DESC, city DESC
Because it's not specifically looking for RG20 7TT, I don't think it can make a partial match.
I have tried SUBSTR (postcode, -4) and looked into left and right, but I haven't had any success using 'by field' and could not find another route...
Sorry this is a bit long winded, but I'm in a bit of a bind.
A UK postcode splits into 2 parts, the last section always being 3 characters and within my database there is a space between the two if that helps at all.
Although there is a DESC after the postcodes, I do need them to display in THAT particular order (RG20, RG14 then RG18 etc..) I'm unsure if specifying descending will remove the ordering or not
Order By Case
When postcode Like 'RG20%' Then 1
When postcode Like 'RG14%' Then 2
When postcode Like 'RG18%' Then 3
When postcode Like 'RG17%' Then 4
When postcode Like 'RG28%' Then 5
When postcode Like 'OX12%' Then 6
When postcode Like 'OX11%' Then 7
Else 99
End Asc
, City Desc
You're on the right track, trimming the field down to its first four characters:
ORDER BY FIELD(LEFT(postcode, 4), 'RG20', 'RG14', ...),
-- or SUBSTRING(postcode FROM 1 FOR 4)
-- or SUBSTR(postcode, 1, 4)
Here you don't want DESC.
(If your result set contains postcodes whose prefixes do not appear in your FIELD() ordering list, you'll have a bit more work to do, since those records will otherwise appear before any explicitly ordered records you specify. Before 'RG20' in the example above.)
If you want a completely custom sorting scheme, then I only see one way to do it...
Create a table to hold the values upon which to sort, and include a "sequence" or "sort_order" field. You can then join to this table and sort by the sequence field.
One note on the sequence field. It makes sense to create it as an int as... well, sequences are often ints :)
If there is any possibility of changing the sort order, you may want to consider making it alpha numeric... It is a lot easier to insert "5A" between "5 and "6" than it is to insert a number into a sequence of integers.
Another method I use is utilising the charindex function:
order by charindex(substr(postcode,4,1),"RG20RG14RG18...",1)
I think that's the syntax anyway, I'm just doing this in SAS at the moment so I've had to adapt from memory!
But essentially the sooner you hit your desired part of the string, the higher the rank.
If you're trying to rank on a large variety of postcodes then a case statement gets pretty hefty.