I've looked a bunch of answers to this question here on SO and elsewhere but all I can track down is cases where people just want to find the highest id, the max dateCreated or the latest db entry but what I want to do is retrieve the latest object created that also matches another criteria. My domain class has the following properties: id, number, company, type, dateCreated and content. The company property can only be set to 'OYG' or 'BAW' and the number property is an auto incrementing int. What I want to do is retrieve the record with the highest number that also has its company property set to 'OYG' or 'BAW`.
So here's an example:
+----------------------------------------------------------+
| id | number | company | type | dateCreated | content |
+----------------------------------------------------------+
| 1 | 0 | OYG | TsAndCs | 15/09/2016 | stuff |
| 2 | 0 | BAW | TsAndCs | 15/09/2016 | stuff |
| 3 | 1 | OYG | TsAndCs | 16/09/2016 | stuff |
| 4 | 2 | OYG | TsAndCs | 17/09/2016 | stuff |
| 5 | 1 | BAW | TsAndCs | 16/09/2016 | stuff |
+----------------------------------------------------------+
I want to say def doc = Document.findByHighestNumberAndCompany('OYG') then it should bring back the object with id 4. def doc = Document.findByHighestNumberAndCompany('BAW') should bring back id 5's object, etc.
Any help would be appreciated. Thanks!
Despite Joshua Moore gave you a good solution, there is another simplier in one line.
MyDomain.findAllByCompany(company, [sort: 'number', order: 'desc', limit: 1])?.first()
Should be easy enough if you order by the number in descending order, and limit your results to one. So perhaps something like this?
String companyName = 'OYG'
def results = MyDomain.createCriteria().list() {
eq("company", companyName)
maxResults(1)
order("number", "desc")
}
println results[0].id // will print 4
Using this approach you could create a named query so you can pass the company name as a parameter.
Related
I created a table (t_subject) like this
| id | description | enabled |
|----|-------------|---------|
| 1 | a | 1 |
| 2 | b | 1 |
| 3 | c | 1 |
And another table (t_place) like this
| id | description | enabled |
|----|-------------|---------|
| 1 | d | 1 |
| 2 | e | 1 |
| 3 | f | 1 |
Right now data from t_subject is used for each of t_place records, to show HTML dropdowns, with all the results from t_subject.
So I simply do
SELECT * FROM t_subject WHERE enabled = 1
Now just for one of t_place records, one record from t_subject should be hidden.
I don't want to simply delete it with javascript, since I want to be able to customize all of the dropdowns if anything changes.
So the first thing I though was to add a place_id column to t_subject.
But this means I have to duplicate all of t_subject records, I would have 3 of each, except one that would have 2.
Is there any way to avoid this??
I thought adding an id_exclusion column to t_subject so I could duplicate records only whenever a record is excluded from another id from t_place.
How bad would that be?? This way I would have no duplicates, so far.
Hope all of this makes sense.
While you only need to exclude one course, I would still recommend setting up a full 'place-course' association. You essentially have a many-to-many relationship, despite not explicitly linking your tables.
I would recommend an additional 'bridging' or 'associative entity' table to represent which courses are offered at which places. This new table would have two columns - one foreign key for the ID of t_subject, and one for the ID of t_place.
For example (t_place_course):
| place_id | course_id |
|----------|-----------|
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 2 | 1 |
| 2 | 2 |
| 2 | 3 |
| 3 | 1 |
| 3 | 3 |
As you can see in my example above, place 3 doesn't offer course 2.
From here, you can simply query all of the courses available for a place by querying the place_id:
SELECT * from t_place_course WHERE place_id = 3
The above will return both courses 1 and 3.
You can optionally use a JOIN to get the other information about the course or place, such as the description:
SELECT `t_course`.`description`
FROM `t_course`
INNER JOIN `t_place_course`
ON `t_course`.`id` = `t_place_course`.`course_id`
INNER JOIN `t_place`
ON `t_place`.`id` = `place_id`
I haven't touched the backend in a while.. so forgive me if this is super simple. I'm working with Lumen v.5.6.1.
| table.sets | | table.indexed_items |
|----------------| |---------------------------------|
| ID | SET | | ID | setId | itemId | have |
|----|-----------| |----|-------|--------|-----------|
| 1 | set name 1| | 1 | 3 | 1 | 2 |
| 2 | set name 2| | 2 | 3 | 2 | 1 |
| 3 | set name 3| | 3 | 3 | 3 | 4 |
| 4 | 2 | 4 | 1 |
| 5 | 2 | 5 | 3 |
| 6 | 2 | 6 | 1 |
How would I return in one query, groupedBy/distinct by setId (with set name as a left join?) to have a return like this:
[
setId: 2,
name: 'set name 2',
haveTotal: 5,
],
[
setId: 3,
name: 'set name 3',
haveTotal: 7,
]
Here is a raw MySQL query which should work. To convert this to Laravel should not be too much work, though you might need to use DB::raw once or twice.
SELECT
s.ID AS setId,
s.`SET` AS name,
COALESCE(SUM(ii.have), 0) AS haveTotal
FROM sets s
LEFT JOIN indexed_items ii
ON s.ID = ii.setId
GROUP BY
s.ID;
Demo
If you don't want to return sets having no entries in the indexed_items table, then you may remove the call to COALESCE, and you may also use an inner join instead of a left join.
Note that using SET to name your tables and columns is not a good idea because it is a MySQL keyword.
If you are using or want to use eloquent, you can do something like:
$sets = App\Sets::withCount('indexed_items')->get();
This will return a collection with a column name indexed_items_count
Obviously you will need to change depending on your model names.
Here are the docs
I always use in my project for count relation ship record.
$sets->indexed_items->count();
I have a table with this sort of data:
+------------+----------+----------+
| Unique ID | Name | Class |
+------------+----------+----------+
| 1 | Name 1 | Class A |
| 2 | Name 2 | "" |
| 3 | Name 3 | Class C |
| 4 | Name 1 | "" |
| 5 | Name 4 | "" |
| 6 | Name 4 | "" |
+------------+----------+----------+
I am trying to do something I thought was simple, but i did not find so.
I am trying to "extract" only the lines with an empty string value in 'Class' for a group of equal names.
So in this case I would get this result :
+------------+----------+--------+
| Unique ID | Name | Class |
+------------+----------+--------+
| 2 | Name 2 | "" |
| 5 | Name 4 | "" |
+------------+----------+--------+
So not Name 1 because even though there is a line with "" there is another line with 'Class A'.
I thought a UNION would do the job but I am not gettgin anything because I think unions are for two tables but the problem here is I have the data in the same table.
Thank you for your help
Access syntax may be a bit different but this returns what you want in Oracle:
SELECT distinct Name, Class FROM table1 Where Name NOT in (select name from table1 where class is not null)
A Union melds two result sets, whether or not they come from the same table is irrelevant. What you want to do is omit from the result set the rows with the same name AND class is not null. Not having your query to expand on or change is a problem, but if you add a clause that says something like where "name not in (select name from table where class is not null);", that may do it.
In one of our columns we store this example json string:
[{"Name":"Pay Amount","Value":"0.00"},{"Name":"Period","Value":"3"},{"Name":"Client","Value":"TestClient"},{"Name":"Our Reference","Value":""},{"Name":"Pay Type","Value":"Test"}]
We repeat the Names through out and the values will differ.
I've tried querying this data using JsonGet_string :
SELECT
JSONGET_string(Header, "Name") Name
FROM tbl
but what it does it selects the first one i.e PayAmount and it only displays a list of payamount it doesn't select anything for Period, Client etc.
The result that it returns looks like this:
| Name |
|----------|
| |
| PayAmount|
| PayAmount|
And it should return this:
| Name |
|-------------|
| |
| PayAmount |
| Period |
| Client |
| OutReference|
| Pay Type |
Any ideas?
The meta function in kdb/q returns the following info about the table:
c – (symbol) column names
t – (char) data type
f – (symbol) domain of foreign keys
a - (symbol) attributes.
I would like to extend this to include more information about the table. The specific case that I am trying to solve is to include the timezone information about the time data columns in the table.
For example:
select from Price
+-------------------------+-------------------------+--------+-------+
| Time | SysTime | Ticker | Price |
+-------------------------+-------------------------+--------+-------+
| 2016.09.15D09:18:02.391 | 2016.09.15D08:18:02.391 | IBM | 63.46 |
| 2016.09.15D09:18:02.491 | 2016.09.15D08:16:22.391 | MSFT | 96.72 |
| 2016.09.15D09:18:02.591 | 2016.09.15D08:14:42.391 | AAPL | 23.06 |
+-------------------------+-------------------------+--------+-------+
meta Price
+---------+---+---+---+
| c | t | f | a |
+---------+---+---+---+
| Time | p | | |
| SysTime | p | | |
| Ticker | s | | |
| Price | f | | |
+---------+---+---+---+
I would like to have additional info about the time data columns (Time and SysTime) in the meta.
For Example, something like this:
metaExtended Price
+---------+---+---+---+------------------+
| c | t | f | a | z |
+---------+---+---+---+------------------+
| Time | p | | | America/New_York |
| SysTime | p | | | America/Chicago |
| Ticker | s | | | |
| Price | f | | | |
+---------+---+---+---+------------------+
Please note that I have a function that takes in the table and column to return the time zone.
TimeZone[Price;Time] returns America/New_York
My question is only about how to include this information in the meta function. The second question that I have is that if the user does something like this, newPriceTable:Price (creating a new table which is the same as the previous table) then the metaExtended function should return the same value for both the tables (akin to calling a function on two different variables having the same object reference)
Does something similar exist in sql?
meta is a reserved word and therefore cannot be redefined. But you can create your own implementation and use it in place of meta:
TimeZone:{[Table;Col] ... } / your TimeZone function
metaExtended:{meta[x],'([]z:TimeZone[t]each cols x)}
metaExtended Price
Regarding your second question, I don't think it's possible to do what you want in k/q. Immediately after assigning Price to newPriceTable the latter is indeed a reference, but as soon as you modify it kdb will create a copy and modify it instead of the original. The problem is there is no way to tell whether newPriceTable is still a reference to Price or a fresh new object.
You can use lj to join them into one metaExtended function.
The function will check for all the time cols and run TimeZone function on them and join the result with meta result:
metaExtended:{[tbl] meta[tbl] lj 1!select c,z:TimeZone[tbl] each t from meta[tbl] where t in "tp"}
metaExtended `t
when you assign this table to new variable it will be assigned as a reference.
nt:t / nt and t pointing to same object
Yo can check the reference count of a variable using -16! .
-16!t
At this point metaExtended function will give same output. But once some update is done on any of these variables pointing to same table, kdb will create a new copy for updated table/variable. From this point they are 2 different objects. Now output of metaExtended function depends on the object schema.