i would like to create table from
SELECT
a.value_text,
a.value_free_text,
a.value_date,
a.value_number
FROM survey_user_input_line a
LEFT JOIN survey_label b on b.id = a.value_suggested
WHERE a.survey_id = %s
ORDER BY question_id, a.user_input_id, id, value_suggested_row
to
can anybody tell me how to code it
You may use a chained call to COALESCE, making sure to cast all columns to a common data type (text makes the most sense here):
SELECT *, COALESCE(value_text, value_free_text, value_date::text,
value_number::text) AS all_value
FROM yourTable;
Related
Adding back some original info for historical purposes as I thought simplifying would help but it didn't. We have this stored procedure, in this part it is selecting records from table A (calldetail_reporting_agents) and doing a left join on table B (Intx_Participant). Apparently there are duplicate rows in table B being pulled that we DON'T want. Is there any easy way to change this up to only pick the first match on table B? Or will I need to rewrite the whole thing?
SELECT 'Agent Calls' AS CallType,
CallDate,
CallTime,
RemoteNumber,
DialedNumber,
RemoteName,
LocalUserId,
CallDurationSeconds,
Answered,
AnswerSpeed,
InvalidCall,
Intx_Participant.Duration
FROM calldetail_reporting_agents
LEFT JOIN Intx_Participant ON calldetail_reporting_agents.CallID = Intx_Participant.CallIDKey
WHERE DialedNumber IN ( SELECT DialedNumber
FROM #DialedNumbers )
AND ConnectedDate BETWEEN #LocStartDate AND #LocEndDate
AND (#LocQueue IS NULL OR AssignedWorkGroup = #LocQueue)
Simpler version: how to change below to select only first matching row from table B:
SELECT columnA, columnB FROM TableA LEFT JOIN TableB ON someColumn
I changed to this per the first answer and all data seems to look exactly as expected now. Thank you to everyone for the quick and attentive help.
SELECT 'Agent Calls' AS CallType,
CallDate,
CallTime,
RemoteNumber,
DialedNumber,
RemoteName,
LocalUserId,
CallDurationSeconds,
Answered,
AnswerSpeed,
InvalidCall,
Intx_Participant.Duration
FROM calldetail_reporting_agents
OUTER APPLY (SELECT TOP 1
*
FROM Intx_Participant ip
WHERE calldetail_reporting_agents.CallID = ip.CallIDKey
AND calldetail_reporting_agents.RemoteNumber = ip.ConnValue
AND ip.HowEnded = '9'
AND ip.Recorded = '0'
AND ip.Duration > 0
AND ip.Role = '1') Intx_Participant
WHERE DialedNumber IN ( SELECT DialedNumber
FROM #DialedNumbers )
AND ConnectedDate BETWEEN #LocStartDate AND #LocEndDate
AND (#LocQueue IS NULL OR AssignedWorkGroup = #LocQueue)
You can try to OUTER APPLY a subquery getting only one matching row.
...
FROM calldetail_reporting_agents
OUTER APPLY (SELECT TOP 1
*
FROM intx_Participant ip
WHERE ip.callidkey = calldetail_reporting_agents.callid) intx_participant
WHERE ...
You should add an ORDER BY in the subquery. Otherwise it isn't deterministic which row is taken as the first. Or maybe that's not an issue.
I'm writing a some filtering logic that basically wants to first check if there's a value in the filter table, then if there is return the filtered values. When there isn't a value in the filter table just return everything. The following table does this correctly but I have to write the same select statement twice.
select *
from personTbl
where (not exists (select filterValue from filterTable where filterType = 'name') or
personTbl.name in (select filterValue from filterTable where filterType = 'name'))
Is there some better way to do this that will return true if the table is empty, or the value is contained within it?
One approach is to do a left outer join to your filter-subquery, and then select all the rows where the join either failed (meaning that the subquery returned no rows) or succeeded and had the right value:
SELECT personTbl.*
FROM personTbl
LEFT
OUTER
JOIN ( SELECT DISTINCT filterValue
FROM filterTable
WHERE filterType = 'name'
) filter
ON 1 = 1
WHERE filter.filterValue = personTbl.name
OR filter.filterValue IS NULL
;
To be honest, I'm not sure if the above is a good idea — it's not very intuitive1, and I'm not sure how well it will perform — but you can judge for yourself.
1. As evidence of its unintuitiveness, witness the mistaken claim below that it doesn't work. As of this writing, that comment has garnered two upvotes. So although the query is correct, it clearly inspires people to great confidence that it's wrong. Which is a nice party trick, but not generally desirable in production code.
You can use a collection to try to make the query more intuitive (and only require a single select from the filter table):
CREATE TYPE filterlist IS TABLE OF VARCHAR2(100);
/
SELECT p.*
FROM PersonTbl p
INNER JOIN
( SELECT CAST(
MULTISET(
SELECT filterValue
FROM filterTable
WHERE filterType = 'name'
)
AS filterlist
) AS filters
FROM DUAL ) f
ON ( f.filters IS EMPTY OR p.name MEMBER OF f.filters );
Here is my query:
SELECT DISTINCT v.codi, m.nom, v.matricula, v.data_compra, v.color,
v.combustible, v.asseguranca,
(CASE WHEN lloguer.dataf IS NOT NULL THEN 'Si' ELSE 'Llogat' END) AS Disponible
FROM vehicle v
INNER JOIN model m on model_codi=m.codi
INNER JOIN lloguer on codi_vehicle=v.codi
WHERE Disponible='Si';
What I'm trying to do it's to show only those rows that have the "lloguer.dataf" is not NULL, but it doesn't alow me to use the "Disponible" alias to do the last line comparison.
What can I do?
This is how the info is shown (with some more atribute) without the last line comparison.
The problem is the alias doesnt exists yet. So you have to repeat the full code or create a subquery.
SELECT *
FROM ( .... ) YourQuery
WHERE Disponible='Si';
You can read more details here https://community.oracle.com/thread/1109532?tstart=0
Remove your CASE WHEN from the SELECT block and replace your WHERE clause with:
WHERE lloguer.dataf IS NOT NULL
I'm a TSQL guy by nature, but can you do this?
Select distinct codi, nom,matricula, data_compra, colour, combustible, asseguranca from
(SELECT DISTINCT v.codi, m.nom, v.matricula, v.data_compra, v.color,
v.combustible, v.asseguranca,
(CASE WHEN lloguer.dataf IS NOT NULL THEN 'Si' ELSE 'Llogat' END) AS Disponible
FROM vehicle v
INNER JOIN model m on model_codi=m.codi
INNER JOIN lloguer on codi_vehicle=v.codi)
WHERE Disponible='Si';
As #JuanCarlosOropeza has stated, the alias doesn't exist until the data is initially fetched. This is why you would be able to use the alias in an order by clause without using a subquery, but not in the where clause as the data hasn't been fetched yet.
I have a simple SQL table containing some values, for example:
id | value (table 'values')
----------
0 | 4
1 | 7
2 | 9
I want to iterate over these values, and use them in a query like so:
SELECT value[0], x1
FROM (some subquery where value[0] is used)
UNION
SELECT value[1], x2
FROM (some subquery where value[1] is used)
...
etc
In order to get a result set like this:
4 | x1
7 | x2
9 | x3
It has to be in SQL as it will actually represent a database view. Of course the real query is a lot more complicated, but I tried to simplify the question while keeping the essence as much as possible.
I think I have to select from values and join the subquery, but as the value should be used in the subquery I'm lost on how to accomplish this.
Edit: I oversimplified my question; in reality I want to have 2 rows from the subquery and not only one.
Edit 2: As suggested I'm posting the real query. I simplified it a bit to make it clearer, but it's a working query and the problem is there. Note that I have hardcoded the value '2' in this query two times. I want to replace that with values from a different table, in the example table above I would want a result set of the combined results of this query with 4, 7 and 9 as values instead of the currently hardcoded 2.
SELECT x.fantasycoach_id, SUM(round_points)
FROM (
SELECT DISTINCT fc.id AS fantasycoach_id,
ffv.formation_id AS formation_id,
fpc.round_sequence AS round_sequence,
round_points,
fpc.fantasyplayer_id
FROM fantasyworld_FantasyCoach AS fc
LEFT JOIN fantasyworld_fantasyformation AS ff ON ff.id = (
SELECT MAX(fantasyworld_fantasyformationvalidity.formation_id)
FROM fantasyworld_fantasyformationvalidity
LEFT JOIN realworld_round AS _rr ON _rr.id = round_id
LEFT JOIN fantasyworld_fantasyformation AS _ff ON _ff.id = formation_id
WHERE is_valid = TRUE
AND _ff.coach_id = fc.id
AND _rr.sequence <= 2 /* HARDCODED USE OF VALUE */
)
LEFT JOIN fantasyworld_FantasyFormationPlayer AS ffp
ON ffp.formation_id = ff.id
LEFT JOIN dbcache_fantasyplayercache AS fpc
ON ffp.player_id = fpc.fantasyplayer_id
AND fpc.round_sequence = 2 /* HARDCODED USE OF VALUE */
LEFT JOIN fantasyworld_fantasyformationvalidity AS ffv
ON ffv.formation_id = ff.id
) x
GROUP BY fantasycoach_id
Edit 3: I'm using PostgreSQL.
SQL works with tables as a whole, which basically involves set operations. There is no explicit iteration, and generally no need for any. In particular, the most straightforward implementation of what you described would be this:
SELECT value, (some subquery where value is used) AS x
FROM values
Do note, however, that a correlated subquery such as that is very hard on query performance. Depending on the details of what you're trying to do, it may well be possible to structure it around a simple join, an uncorrelated subquery, or a similar, better-performing alternative.
Update:
In view of the update to the question indicating that the subquery is expected to yield multiple rows for each value in table values, contrary to the example results, it seems a better approach would be to just rewrite the subquery as the main query. If it does not already do so (and maybe even if it does) then it would join table values as another base table.
Update 2:
Given the real query now presented, this is how the values from table values could be incorporated into it:
SELECT x.fantasycoach_id, SUM(round_points) FROM
(
SELECT DISTINCT
fc.id AS fantasycoach_id,
ffv.formation_id AS formation_id,
fpc.round_sequence AS round_sequence,
round_points,
fpc.fantasyplayer_id
FROM fantasyworld_FantasyCoach AS fc
-- one row for each combination of coach and value:
CROSS JOIN values
LEFT JOIN fantasyworld_fantasyformation AS ff
ON ff.id = (
SELECT MAX(fantasyworld_fantasyformationvalidity.formation_id)
FROM fantasyworld_fantasyformationvalidity
LEFT JOIN realworld_round AS _rr
ON _rr.id = round_id
LEFT JOIN fantasyworld_fantasyformation AS _ff
ON _ff.id = formation_id
WHERE is_valid = TRUE
AND _ff.coach_id = fc.id
-- use the value obtained from values:
AND _rr.sequence <= values.value
)
LEFT JOIN fantasyworld_FantasyFormationPlayer AS ffp
ON ffp.formation_id = ff.id
LEFT JOIN dbcache_fantasyplayercache AS fpc
ON ffp.player_id = fpc.fantasyplayer_id
-- use the value obtained from values again:
AND fpc.round_sequence = values.value
LEFT JOIN fantasyworld_fantasyformationvalidity AS ffv
ON ffv.formation_id = ff.id
) x
GROUP BY fantasycoach_id
Note in particular the CROSS JOIN which forms the cross product of two tables; this is the same thing as an INNER JOIN without any join predicate, and it can be written that way if desired.
The overall query could be at least a bit simplified, but I do not do so because it is a working example rather than an actual production query, so it is unclear what other changes would translate to the actual application.
In the example I create two tables. See how outer table have an alias you use in the inner select?
SQL Fiddle Demo
SELECT T.[value], (SELECT [property] FROM Table2 P WHERE P.[value] = T.[value])
FROM Table1 T
This is a better way for performance
SELECT T.[value], P.[property]
FROM Table1 T
INNER JOIN Table2 p
on P.[value] = T.[value];
Table 2 can be a QUERY instead of a real table
Third Option
Using a cte to calculate your values and then join back to the main table. This way you have the subquery logic separated from your final query.
WITH cte AS (
SELECT
T.[value],
T.[value] * T.[value] as property
FROM Table1 T
)
SELECT T.[value], C.[property]
FROM Table1 T
INNER JOIN cte C
on T.[value] = C.[value];
It might be helpful to extract the computation to a function that is called in the SELECT clause and is executed for each row of the result set
Here's the documentation for CREATE FUNCTION for SQL Server. It's probably similar to whatever database system you're using, and if not you can easily Google for it.
Here's an example of creating a function and using it in a query:
CREATE FUNCTION DoComputation(#parameter1 int)
RETURNS int
AS
BEGIN
-- Do some calculations here and return the function result.
-- This example returns the value of #parameter1 squared.
-- You can add additional parameters to the function definition if needed
DECLARE #Result int
SET #Result = #parameter1 * #parameter1
RETURN #Result
END
Here is an example of using the example function above in a query.
SELECT v.value, DoComputation(v.value) as ComputedValue
FROM [Values] v
ORDER BY value
I have a table that represents an Object. It has many columns but also fields that require language support.
For simplicity let's say I have 3 tables:
MainObjectTable
LanguageDependantField1
LanguageDependantField2.
MainObjectTable has a PK int called ID, and both LanguageDependantTables have a foreign key link back to the MainObjectTable along with a language code and the date they were added.
I've created a stored procedure that accepts the MainObjectTable ID and a Language. It will return a single row containing the most recent items from the language tables. The select statement looks like
SELECT
MainObjectTable.VariousColumns,
LanguageDependantField1.Description,
LanguageDependantField2.SomeOtherText
FROM
MainObjectTable
OUTER APPLY
(SELECT TOP 1 LanguageDependantField1.Description
FROM LanguageDependantField1
WHERE LanguageDependantField1.MainObjectTable_ID = MainObjectTable.ID
AND LanguageDependantField1.Language_ID = #language
ORDER BY
LanguageDependantField1.[Default], LanguageDependantField1.CreatedDate DESC) LanguageDependantField1
OUTER APPLY
(SELECT TOP 1 LanguageDependantField2.SomeOtherText
FROM LanguageDependantField2
WHERE LanguageDependantField2.MainObjectTable_ID = MainObjectTable.ID
AND LanguageDependantField2.Language_ID = #language
ORDER BY
LanguageDependantField2.[Default] DESC, LanguageDependantField2.CreatedDate DESC) LanguageDependantField2
WHERE
MainObjectTable.ID = #MainObjectTableID
What I want to add is the ability to fallback to a default language if a row isn't found in the specified language. Let's say we use "German" as the selected language. Is it possible to return an English row from LanguageDependantField1 if the German does not exist presuming we have #fallbackLanguageID
Also am I right to use OUTER APPLY in this scenario or should I be using JOIN?
Many thanks for your help.
Try this:
SELECT MainObjectTable.VariousColumns,
COALESCE(PrefLang.Description,Fallback.Description,'Not Found Desc')
as Description,
COALESCE(PrefLang.SomeOtherText,FallBack.SomeOtherText,'Not found')
as SomeOtherText
FROM MainObjectTable
LEFT JOIN
(SELECT TOP 1 pl.Description,pl.SomeOtherText
FROM LanguageDependantField1 pl
WHERE pl.MainObjectTable_ID = MainObjectTable.ID
AND pl.Language_ID = #language
ORDER BY
pl.[Default], pl.CreatedDate DESC)
PrefLang ON 1=1
LEFT JOIN
(SELECT TOP 1 fb.Description,fb.SomeOtherText
FROM LanguageDependantField1 fb
WHERE fb.MainObjectTable_ID = MainObjectTable.ID
AND fb.Language_ID = #fallbackLanguageID
ORDER BY
fb.[Default], fb.CreatedDate DESC)
Fallback ON 1=1
WHERE
MainObjectTable.ID = #MainObjectTableID
Basically, make two queries, one to the preferred language and one to English (Default). Use the LEFT JOIN, so if the first one isn't found, the second query is used...
I don't have your actual tables, so there might be a syntax error in above, but hope it gives you the concept you want to try...
Yes, the use of Outer Apply is correct if you want to correlate the MainObjectTable table rows to the inner queries. You cannot use Joins with references in the derived table to the outer table. If you wanted to use Joins, you would need to include the joining column(s) and in this case pre-filter the results. Here is what that might look like:
With RankedLanguages As
(
Select LDF1.MainObjectTable_ID, LDF1.Language_ID, LDF1.Description, LDF1.SomeOtherText, ...
, Row_Number() Over ( Partition By LDF1.MainObjectTable_ID, LDF1.Language_ID
Order By LDF1.[Default] Desc, LDF1.CreatedDate Desc ) As Rnk
From LanguageDependantField1 As LDF1
Where LDF1.Language_ID In( #languageId, #defaultLanguageId )
)
Select M.VariousColumns
, Coalesce( SpecificLDF.Description, DefaultLDF.Description ) As Description
, Coalesce( SpecificLDF.SomeOtherText, DefaultLDF.SomeOtherText ) As SomeOtherText
, ...
From MainObjectTable As M
Left Join RankedLanguages As SpecificLDF
On SpecificLDF.MainObjectTable_ID = M.ID
And SpecifcLDF.Language_ID = #languageId
And SpecifcLDF.Rnk = 1
Left Join RankedLanguages As DefaultLDF
On DefaultLDF.MainObjectTable_ID = M.ID
And DefaultLDF.Language_ID = #defaultLanguageId
And DefaultLDF.Rnk = 1
Where M.ID = #MainObjectTableID