I am using Tableau to create custom queries, I need to pass the results from one custom query into another. So for example one custom query might have the following query:
select *
from bime.test_tab
where record_date = '2018-05-21'.
I then create another custom query which uses the results from the query above. Is this possible?
Sure you can by making this custom query as a subquery
select * from (select *
from bime.test_tab
where record_date = '2018-05-21') a
As you might already know that we do not have a leverage to use temp tables in Tableau custom queries, hence we usually create subqueries for that.
Considering your case,
SELECT BIM_TABLE.* FROM
(SELECT * FROM
BIME.TEST_TAB WHERE RECORD_DATE= '2018-05-21')BIM_TABLE
You can post your actual problem with the relevant columns if you need further help.
PS - It's advised to do most of your data manipulations in SQL itself (if you are running your workbook on live connection), as Tableau is not able to properly optimize part of the 'Custom SQL' query.
Related
I have a mongo database and I'm trying to write an Eloquent code to change some fields before using them in WHERE or ORDER BY clauses. something like this SQL query:
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Where ht.title = 'OrangeHotel'
-- or --
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Order by ht.title
sometimes there is no other table and I just need to use calculated field in Where or Order By clause:
Select *
from agency
Where func(agency_admin) = 'testAdmin'
Select *
from agency
Order by func(agency_admin)
where func() is my custom function.
any suggestion?
and I have read Laravel 4/5, order by a foreign column for half of my problem, but I don't know how can I use it.
For the first query: mongodb only support "join" partially with the aggregation pipeline, which limits your aggregation in one collection. For "join"s between different collections/tables, just select from collections one by one, first the one containing the "where" field, then the one who should "join" with the former, and so on.
The second question just puzzled me for some minutes until I see this question and realized it's the same as your first question: sort the collection containing your sort field and retrive some data, then go to another.
For the 3rd question, this question should serve you well.
Basically I want to retrieve rows of data that meet my clause conditions using Power Query.
I got 400 rows of lookup values in my spreadsheet.
Each row represent 1 lookup code for example, code AAA1, AAB2 and so on
So lets say I have a select statement and I want to construct the where clauses using the above codes so my end sql statement will look like
select * from MyTable where Conditions in ('AA1', 'AAB2')
so so far I have this
let
Source = Excel.CurrentWorkbook(){[Name="Table5"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Form ID",
Int64.Type}}),
test = Sql.Database("myserver", "myDB", [Query="SELECT * FROM myTable where" & #"Changed Type" & "])"
in
test
Obviously that didnt work but thats my pseduo scenario anyway.
Please could you advice what to do?
Thank you
Peddie
I would create a "lookup" Power Query based on the Excel table. I would set the "Load To" properties to "Only Create Connection".
Then I would start the main Query by connecting to the SQL server using the Navigator to select "MyTable". Then I would add a Merge step to the main Query, to join to the "lookup" Query, matching the "Conditions" column to the "lookup" code. I would set the Join Type to "Inner". The Merge properties window will show you visually if the 2 columns you select actually contain matching data.
This approach does not require any coding, and is easier to build, extend and maintain.
Mike Honey's join is best for your problem, but here's a more general solution if you find yourself needing other logic in your where clause.
Normally Power query only generates row filters on an equality expression, but you can put any code you want in a Table.SelectRows filter, like each List.Contains({"AA1", "AAB2"}, [Conditions])
So for your table, your query would look something like:
let
Source = Excel.CurrentWorkbook(){[Name="Table5"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Form ID", Int64.Type}}),
test = Sql.Database("myserver", "myDB"),
yourTable = test{[Name="myTable"]}[Data],
filtered = Table.SelectRows(yourTable, each List.Contains(#"Changed Type"[Form ID], [Conditions]))
in
filtered
The main downside to using the library functions is that Table.SelectRows only knows how to generate SQL where clauses for specific expression patterns, so the row filter probably runs on your machine after downloading the whole table, instead of having the Sql Server run the filter.
I have a query like this, which we use to generate data for our custom dashboard (A Rails app) -
SELECT AVG(wait_time) FROM (
SELECT TIMESTAMPDIFF(MINUTE,a.finished_time,b.start_time) wait_time
FROM (
SELECT max(start_time + INTERVAL avg_time_spent SECOND) finished_time, branch
FROM mytable
WHERE name IN ('test_name')
AND status = 'SUCCESS'
GROUP by branch) a
INNER JOIN
(
SELECT MIN(start_time) start_time, branch
FROM mytable
WHERE name IN ('test_name_specific')
GROUP by branch) b
ON a.branch = b.branch
HAVING avg_time_spent between 0 and 1000)t
GROUP BY week
Now I am trying to port this to tableau, and I am not being able to find a way to represent this data in tableau. I am stuck at how to represent the inner group by in a calculated field. I can also try to just use a custom sql data source, but I am already using another data source.
columns in mytable -
start_time
avg_time_spent
name
branch
status
I think this could be achieved new Level Of Details formulas, but unfortunately I am stuck at version 8.3
Save custom SQL for rare cases. This doesn't look like a rare case. Let Tableau generate the SQL for you.
If you simply connect to your table, then you can usually write calculated fields to get the information you want. I'm not exactly sure why you have test_name in one part of your query but test_name_specific in another, so ignoring that, here is a simplified example to a similar query.
If you define a calculated field called worst_case_test_time
datediff(min(start_time), dateadd('second', max(start_time), avg_time_spent)), which seems close to what your original query says.
It would help if you explained what exactly you are trying to compute. It appears to be some sort of worst case bound for avg test time. There may be an even simpler formula, but its hard to know without a little context.
You could filter on status = "Success" and avg_time_spent < 1000, and place branch and WEEK(start_time) on say the row and column shelves.
P.S. Your query seems a little off. Don't you need an aggregation function like MAX or AVG after the HAVING keyword?
I want to do something like this in OrmLite
SELECT *, COUNT(title) as titleCount from table1 group by title;
Is there any way to do this via QueryBuilder without the need for queryRaw?
The documentation states that the use of COUNT() and the like necessitates the use of selectRaw(). I hoped for a way around this - not having to write my SQL as strings is the main reason I chose to use ORMLite.
http://ormlite.com/docs/query-builder
selectRaw(String... columns):
Add raw columns or aggregate functions
(COUNT, MAX, ...) to the query. This will turn the query into
something only suitable for using as a raw query. This can be called
multiple times to add more columns to select. See section Issuing Raw
Queries.
Further information on the use of selectRaw() as I was attempting much the same thing:
Documentation states that if you use selectRaw() it will "turn the query into" one that is supposed to be called by queryRaw().
What it does not explain is that normally while multiple calls to selectColumns() or selectRaw() are valid (if you exclusively use one or the other),
use of selectRaw() after selectColumns() has a 'hidden' side-effect of wiping out any selectColumns() you called previously.
I believe that the ORMLite documentation for selectRaw() would be improved by a note that its use is not intended to be mixed with selectColumns().
QueryBuilder<EmailMessage, String> qb = emailDao.queryBuilder();
qb.selectColumns("emailAddress"); // This column is not selected due to later use of selectRaw()!
qb.selectRaw("COUNT (emailAddress)");
ORMLite examples are not as plentiful as I'd like, so here is a complete example of something that works:
QueryBuilder<EmailMessage, String> qb = emailDao.queryBuilder();
qb.selectRaw("emailAddress"); // This can also be done with a single call to selectRaw()
qb.selectRaw("COUNT (emailAddress)");
qb.groupBy("emailAddress");
GenericRawResults<String[]> rawResults = qb.queryRaw(); // Returns results with two columns
Is there any way to do this via QueryBuilder without the need for queryRaw(...)?
The short answer is no because ORMLite wouldn't know what to do with the extra count value. If you had a Table1 entity with a DAO definition, what field would the COUNT(title) go into? Raw queries give you the power to select various fields but then you need to process the results.
With the code right now (v5.1), you can define a custom RawRowMapper and then use the dao.getRawRowMapper() method to process the results for Table1 and tack on the titleCount field by hand.
I've got an idea how to accomplish this in a better way in ORMLite. I'll look into it.
I'm using Zend Framework for my website and I'd like to retrieve some data from my PostgreSQL database.
I have a request like :
SELECT DISTINCT ON(e.id) e.*, f.*, g.* FROM e, f, g
WHERE e.id = f.id_e AND f.id = g.id_f
This request works well but I don't know how to convert the DISTINCT ON(e.id) with Zend.
It seems that I can get DISTINCT rows but no distinct columns.
$select->distinct()->from("e")->join("f", "e.id = f.id_e")
->join("g", "f.id = g.id_f");
Any idea on how to make a select with distinct column ?
Thanks for help
You probably can't do this with Zend Framework since distinct on is not part of the SQL standard (end of page in Postgres documentation). Although Postgres supports it, I would assume its not part of Zend Framework because you could in theory configure another database connection which does not offer support.
If you know in advance that you're developing for a specific database (Postgres in this case), you could use manually written statements instead. You'll gain more flexibility within the queries and better performance at the cost of no longer being able to switch databases.
You would then instantiate a Zend_Db_Apdapter for Postgres. There a various methods available to get results for SQL queries which are described in the frameworks documentation starting at section Reading Query Results. If you choose to go this route I'd recommend to create an own subclass of the Zend_Db_Adapter_Pgsql class. This is to be able to convert data types and throw exceptions in case of errors instead of returning ambiguous null values and hiding error causes.