I am using an oracle database I am buidling a query and am unsure how to do a compare with the field I set as 'Created'
SELECT C.IS_AW_TITLE, A.PORTAL_OBJNAME, C.IS_AW_ACTIVE_FLG,
(TO_CHAR(CAST((C.CREATEDTTM) AS TIMESTAMP),'YYYY-MM-DD-HH24.MI.SS.FF')) AS
CREATED,.....
FROM ..., (sysadm.PS_IS_AW_PG_DEFN C LEFT OUTER JOIN sysadm.PS_IS_AW_SECURITY D ON
C.IS_AW_GRP_ID = D.IS_AW_GRP_ID ),...
WHERE ( C.IS_AW_CREF_OBJ = A.PORTAL_OBJNAME
AND C.IS_AW_GRP_ID = E.IS_AW_GRP_ID...
the 'Created' field produces results similar to this example: 2011-09-26-11.22.31.000000
How would I include it in the query to say something like 'AND Created = to_timestamp(....., 2011-09-26-11.22.31.000000)?
You have let's say declared (not sure whether term is appropriate, feel free to correct me) created field as to_char, so its type is varchar2, that means you cannot compare it with to_timestamp.
I see several ways to do such comparsion:
Leave field as is, and compare CAST((C.CREATEDTTM) AS TIMESTAMP with the date you need;
Define created as timestamp, i.e. remove to_char;
Compare created with `to_char(to_timestamp(...));
Which one is the best fit would depend on how you're going to use created field in query result. If possible, personally I'd choose option 2.
Related
I'm trying to figure out from a column type, which aggregates the data type supports. There's a lot of variety amongst types, just a sample below (some of these support more aggregates, of course):
uuid count()
text count(), min(), max()
integer count(), min, max(),avg(),sum()
I've been thrashing around in the system catalogs and views, but haven't found what I'm after. (See "thrashing around.") I've poked at pg_type, pg_aggregate, pg_operator, and a few more.
Is there a straightforward way to start from a column type and gather all supported aggregates?
For background, I'm writing a client-side cross-tab code generator, and the UX is better when the tool automatically prevents you from selecting an aggregation that's not supported. I've hacked in some hard-coded rules for now, but would like to improve the system.
We're on Postgres 11.4.
A plain list of available aggregate functions can be based on pg_proc like this:
SELECT oid::regprocedure::text AS agg_func_plus_args
FROM pg_proc
WHERE prokind = 'a'
ORDER BY 1;
Or with separate function name and arguments:
SELECT proname AS agg_func, pg_get_function_identity_arguments(oid) AS args
FROM pg_proc
WHERE prokind = 'a'
ORDER BY 1, 2;
pg_proc.prokind replaces proisagg in Postgres 11. In Postgres 10 or older use:
...
WHERE proisagg
...
Related:
How to drop all of my functions in PostgreSQL?
How to get function parameter lists (so I can drop a function)
To get a list of available functions for every data type (your question), start with:
SELECT type_id::regtype::text, array_agg(proname) AS agg_functions
FROM (
SELECT proname, unnest(proargtypes::regtype[])::text AS type_id
FROM pg_proc
WHERE proisagg
ORDER BY 2, 1
) sub
GROUP BY type_id;
db<>fiddle here
Just a start. Some of the arguments are just "direct" (non-aggregated) (That's also why some functions are listed multiple times - due to those additional non-aggregate columns, example string_agg). And there are special cases for "ordered-set" and "hypothetical-set" aggregates. See the columns aggkind and aggnumdirectargs of the additional system catalog pg_aggregate. (You may want to exclude the exotic special cases for starters ...)
And many types have an implicit cast to one of the types listed by the query. Prominent example string_agg() works with varchar, too, but it's only listed for text above. You can extend the query with information from pg_cast to get the full picture.
Plus, some aggregates work for pseudo types "any", anyarray etc. You'll want to factor those in for every applicable data type.
The complication of multiple aliases for the same data type names can be eliminated easily, though: cast to regtype to get canonical names. Or use pg_typeof() which returns standard names. Related:
Type conversion. What do I do with a PostgreSQL OID value in libpq in C?
PostgreSQL syntax error in parameterized query on "date $1"
How do I translate PostgreSQL OID using python
Man, that is just stunning Thank you. The heat death of the universe will arrive before I could have figured that out. I had to tweak one line for PG 11 compatibility...says the guy who did not say what version he was on. I've reworked the query to get close to what I'm after and included a bit of output for the archives.
with aggregates as (
SELECT pro.proname aggregate_name,
CASE
WHEN array_agg(typ.typname ORDER BY proarg.position) = '{NULL}'::name[] THEN
'{}'::name[]
ELSE
array_agg(typ.typname ORDER BY proarg.position)
END aggregate_types
FROM pg_proc pro
CROSS JOIN LATERAL unnest(pro.proargtypes) WITH ORDINALITY proarg (oid,
position)
LEFT JOIN pg_type typ
ON typ.oid = proarg.oid
WHERE pro. prokind = 'a' -- I needed this for PG 11, I didn't say what version I was using.
GROUP BY pro.oid,
pro.proname
ORDER BY pro.proname),
-- The *super helpful* code above is _way_ past my skill level with Postgres. So, thrashing around a bit to get close to what I'm after.
-- First up, a CTE to sort everything by aggregation and then combine the types.
aggregate_summary as (
select aggregate_name,
array_agg(aggregate_types) as types_array
from aggregates
group by 1
order by 1)
-- Finally, the previous CTE is used to get the details and a count of the types.
select aggregate_name,
cardinality(types_array) as types_count, -- Couldn't get array_length to work here. ¯\_(ツ)_/¯
types_array
from aggregate_summary
limit 5;
And a bit of output:
aggregate_name types_count types_array
array_agg 2 {{anynonarray},{anyarray}}
avg 7 {{int8},{int4},{int2},{numeric},{float4},{float8},{interval}}
bit_and 4 {{int2},{int4},{int8},{bit}}
bit_or 4 {{int2},{int4},{int8},{bit}}
bool_and 1 {{bool}}
Still on my wish list are
Figuring out how to execute arrays (we aren't using array fields now, and only have a few places that we ever might. At that point, I don't expect we'll try and support pivots on arrays. tab tool
Getting all of the aliases for the various types. it seems like (?) int8, etc. can come through from pg_attribute in multiple ways. For example, timestamptz can come back from "timestamp with time zone".
These results are going to be consumed by client-side code and processed, so I don't need to get Postgres to figure everything out in one query, just enough for me to get the job done.
In any case, thanks very, very much.
There's the pg_proc catalog table, that lists all functions. The column proisagg marks aggregation functions and the column proargtypes holds an array of the OIDs of the argument types.
So for example to get a list of all aggregation functions with the names of their arguments' type you could use:
SELECT pro.proname aggregationfunctionname,
CASE
WHEN array_agg(typ.typname ORDER BY proarg.position) = '{NULL}'::name[] THEN
'{}'::name[]
ELSE
array_agg(typ.typname ORDER BY proarg.position)
END aggregationfunctionargumenttypes
FROM pg_proc pro
CROSS JOIN LATERAL unnest(pro.proargtypes) WITH ORDINALITY proarg (oid,
position)
LEFT JOIN pg_type typ
ON typ.oid = proarg.oid
WHERE pro.proisagg
GROUP BY pro.oid,
pro.proname
ORDER BY pro.proname;
Of course you may need to extend that, e.g. joining and respecting the schemas (pg_namespace) and check for compatible types in pg_type (have a look at the typcategory column for that), etc..
Edit:
I overlooked, that proisagg was removed in version 11 (I'm still mostly on a 9.6) as the other answers mentioned. So for the sake of completeness: As of version 11 replace WHERE pro.proisagg with WHERE pro.prokind = 'a'.
I've been playing around with the suggestions a bit, and want to post one adaptation based on one of Erwin's scripts:
select type_id::regtype::text as type_name,
array_agg(proname) as aggregate_names
from (
select proname,
unnest(proargtypes::regtype[])::text AS type_id
from pg_proc
where prokind = 'a'
order by 2, 1
) subquery
where type_id in ('"any"', 'bigint', 'boolean','citext','date','double precision','integer','interval','numeric','smallint',
'text','time with time zone','time without time zone','timestamp with time zone','timestamp without time zone')
group by type_id;
That brings back details on the types specified in the where clause. Not only is this useful for my current work, it's useful to my understanding generally. I've run into cases where I've had to recast something, like an integer to a double, to get it to work with an aggregate. So far, this has been pretty much trial and error. If you run the query above (or one like it), it's easier to see from the output where you need recasting between similar seeming types.
I am working on a small project for an online databases course and i was wondering if you could help me out with a problem I am having.
I have a web page that is searching a movie database and retrieving specific columns using a movie initial input field, a number input field, and a code field. These will all be converted to strings and used as user input for the query.
Below is what i tried before:
select A.CD, A.INIT, A.NBR, A.STN, A.ST, A.CRET_ID, A.CMNT, A.DT
from MOVIE_ONE A
where A.INIT = :init
AND A.CD = :cd
AND A.NBR = :num
The way the page must search is in three different cases:
(initial and number)
(code)
(initial and number and code)
The cases have to be independent so if certain field are empty, but fulfill a certain case, the search goes through. It also must be in one query. I am stuck on how to implement the cases.
The parameters in the query are taken from the Java parameters in the method found in an SQLJ file.
If you could possibly provide some aid on how i can go about this problem, I'd greatly appreciate it!
Consider wrapping the equality expressions in NVL (synonymous to COALESCE) so if parameter inputs are blank, corresponding column is checked against itself. Also, be sure to kick the a-b-c table aliasing habit.
SELECT m.CD, m.INIT, m.NBR, m.STN, m.ST, m.CRET_ID, m.CMNT, m.DT
FROM MOVIE_ONE m
WHERE m.INIT = NVL(:init, m.INIT)
AND m.CD = NVL(:cd, m.CD)
AND m.NBR = COALESCE(:num, m.NBR)
To demonstrate, consider below DB2 fiddles where each case can be checked by adjusting value CTE parameters all running on same exact data.
Case 1
WITH
i(init) AS (VALUES('db2')),
c(cd) AS (VALUES(NULL)),
n(num) AS (VALUES(53)),
cte AS
...
Case 2
WITH
i(init) AS (VALUES(NULL)),
c(cd) AS (VALUES(2018)),
n(num) AS (VALUES(NULL)),
cte AS
...
Case 3
WITH
i(init) AS (VALUES('db2')),
c(cd) AS (VALUES(2018)),
n(num) AS (VALUES(53)),
cte AS
...
However, do be aware the fiddle runs a different SQL due to nature of data (i.e., double and dates). But query does reflect same concept with NVL matching expressions on both sides.
SELECT *
FROM cte, i, c, n
WHERE cte.mytype = NVL(i.init, cte.mytype)
AND YEAR(CAST(cte.mydate AS date)) = NVL(c.cd, YEAR(CAST(cte.mydate AS date)))
AND ROUND(cte.mynum, 0) = NVL(n.num, ROUND(cte.mynum, 0));
I have database that contains data points from various sensors. These data points are taken twice a minute.
I am using the following SQL query to attempt to get two separate data points at two different times.
SELECT *
FROM TableName
WHERE TagName = 'TagName'
AND ("DateTime" = 'X' OR "DateTime" = 'Y')
I see no reason why this should not return 2 data points, one for the first date, and one for the second, but for some reason the query only returns the row for Y.
I feel like I am missing something extremely obvious.
For a bit more context, this query is used in conjuction with a python script to grab data between two dates using a specific resolution.
Any ideas?
EDIT: I believe it has something to do with the structure of the database and how it operates in terms of giving entries a time value.
It needs more investigation on my part so im going to flag this question for deletion, thanks all for you help
Not sure if that is a mistype in your question, but if not, it is probably the " after the AND part of the statement:
AND ("DateTime" = 'X' OR "DateTime" = 'Y')
It should be AND (DateTime = 'X' OR DateTime = 'Y'). Notice no quotes.
http://sqlfiddle.com/#!2/ed00ba/3
I am using SQL server 2005, querying with Web Developer 2010, and the min function appears to be returning more than one value (for each ID returned, see below). Ideally I would like it to just return the one for each ID.
SELECT Production.WorksOrderOperations.WorksOrderNumber,
MIN(Production.WorksOrderOperations.OperationNumber) AS Expr1,
Production.Resources.ResourceCode,
Production.Resources.ResourceDescription,
Production.WorksOrderExcel_ExcelExport_View.PartNumber,
Production.WorksOrderOperations.PlannedQuantity,
Production.WorksOrderOperations.PlannedSetTime,
Production.WorksOrderOperations.PlannedRunTime
FROM Production.WorksOrderOperations
INNER JOIN Production.Resources
ON Production.WorksOrderOperations.ResourceID = Production.Resources.ResourceID
INNER JOIN Production.WorksOrderExcel_ExcelExport_View
ON Production.WorksOrderOperations.WorksOrderNumber = Production.WorksOrderExcel_ExcelExport_View.WorksOrderNumber
WHERE Production.WorksOrderOperations.WorksOrderNumber IN
( SELECT WorksOrderNumber
FROM Production.WorksOrderExcel_ExcelExport_View AS WorksOrderExcel_ExcelExport_View_1
WHERE (WorksOrderSuffixStatus = 'Proposed'))
AND Production.Resources.ResourceCode IN ('1303', '1604')
GROUP BY Production.WorksOrderOperations.WorksOrderNumber,
Production.Resources.ResourceCode,
Production.Resources.ResourceDescription,
Production.WorksOrderExcel_ExcelExport_View.PartNumber,
Production.WorksOrderOperations.PlannedQuantity,
Production.WorksOrderOperations.PlannedSetTime,
Production.WorksOrderOperations.PlannedRunTime
If you can get your head around it, I am selecting certain columns from multiple tables where the WorksOrderNumber is also contained within a subquery, and numerous other conditions.
Result set looks a little like this, have blurred out irrelevant data.
http://i.stack.imgur.com/5UFIp.png (Wouldn't let me embed image).
The highlighted rows are NOT supposed to be there, I cannot explicitly filter them out, as this result set will be updated daily and it is likely to happen with a different record.
I have tried casting and converting the OperationNumber to numerous other data types, varchar type returns '100' instead of the '30'. Also tried searching search engines, no one seems to have the same problem.
I did not structure the tables (they're horribly normalised), and it is not possible to restructure them.
Any ideas appreciated, many thanks.
The MIN function returns the minimum within the group.
If you want the minimum for each ID you need to get group on just ID.
I assume that by "ID" you are referring to Production.WorksOrderOperations.WorksOrderNumber.
You can add this as a "table" in your SQL:
(SELECT Production.WorksOrderOperations.WorksOrderNumber,
MIN(Production.WorksOrderOperations.OperationNumber)
FROM Production.WorksOrderOperations
GROUP BY Production.WorksOrderOperations.WorksOrderNumber)
I'm having trouble with Microsoft Access 2003, it's complaining about this statement:
select cardnr
from change
where year(date)<2009
group by cardnr
having max(time+date) = (time+date) and cardto='VIP'
What I want to do is, for every distinct cardnr in the table change, to find the row with the latest (time+date) that is before year 2009, and then just select the rows with cardto='VIP'.
This validator says it's OK, Access says it's not OK.
This is the message I get: "you tried to execute a query that does not include the specified expression 'max(time+date)=time+date and cardto='VIP' and cardnr=' as part of an aggregate function."
Could someone please explain what I'm doing wrong and the right way to do it? Thanks
Note: The field and table names are translated and do not collide with any reserved words, I have no trouble with the names.
Try to think of it like this - HAVING is applied after the aggregation is done.
Therefore it can not compare to unaggregated expressions (neither for time+date, nor for cardto).
However, to get the last (principle is the same for getting rows related to other aggregated functions as weel) time and date you can do something like:
SELECT cardnr
FROM change main
WHERE time+date IN (SELECT MAX(time+date)
FROM change sub
WHERE sub.cardnr = main.cardnr AND
year(date)<2009
AND cardto='VIP')
(assuming that date part on your time field is the same for all the records; having two fields for date/time is not in your best interest and also using reserved words for field names can backfire in certain cases)
It works because the subquery is filtered only on the records that you are interested in from the outer query.
Applying the same year(date)<200 and cardto='VIP' to the outer query can improve performance further.