SELECT peridle, CPU
FROM (SELECT MAX(peridle) FROM try2);
While executing this query in hive I am getting following error
Parse Error: line 1:47 cannot recognize input near 'select' 'MAX' '(' in expression specification
Please suggest a solution how to use aggregate functions in hive subquery
At least two things need to be fixed here:
You are not returning fields named peridle or CPU from the sub-query, yet you are trying to select them.
Hive requires you to alias all sub-queries, even if you don't reference the alias. You can quickly do this by changing the ); at the end to ) x; (or however you want to call it).
Related
I'm new to PostgreSQL, and I have the following code
select unnest(xpath(
'//ns2:ProcedureCategory/text()',messagebody::xml,
array[array['ns2','urn:wco:datamodel:WCO:DEC-DMS:2']]
))::text
from sw_customs_message scm
where unnest(xpath(
'//ns2:ProcedureCategory/text()',messagebody::xml,
array[array['ns2','urn:wco:datamodel:WCO:DEC-DMS:2']]
))::text = 'H7'
and I get the error message
SQL Error [0A000]: ERROR: set-returning functions are not allowed in WHERE
Position: 172
Set returning functions should be used in the FROM clause. Then you can also reference the result columns in the WHERE clause:
select u.val::text
from sw_customs_message scm
cross join unnest(xpath('//ns2:ProcedureCategory/text()',
scm.messagebody::xml,
array[array['ns2','urn:wco:datamodel:WCO:DEC-DMS:2']])) as u(val)
where u.val::text = 'H7'
Note that typically xmltable() is easier and more flexible to use if you want to turn an XML value into rows and columns. And if you are storing XML in a column, the column should be defined as xml not something else.
I am having issues with combining couple of different things together. I have tried a lot of things suggested on SO but nothing worked, hence posting my question.
So the requirements are
I need to build the dynamic query (to search jsonb column type) in Java
I need to use prepared statements of Java (to avoid sql injection)
I need to replace parameter which is inside single quotes
This query in CLI works perfectly
select * from items where cnt ## '$.**.text like_regex "#finance" flag "i"';
The bit that I want to parameterise is "#finance". So when I build this query
select * from items where cnt ## '$.**.text like_regex ? flag "i"';
When executing I get following error
"The column index is out of range: 1, number of columns: 0."
It's because ? is within single quote so jdbc driver is not able to identify as replaceable parameter perhaps.
The closest question/discussion I could find is in this post: JDBC Prepared statement parameter inside json.
I have tried it however this does not work for me for some reason. They query now I run is
select * from items where cnt ## ?::jsonb
but with this I get following error
org.postgresql.util.PSQLException: ERROR: operator does not exist: jsonb ## jsonb
Hint: No operator matches the given name and argument types. You might need to add explicit type casts.
Position: 106
I have tried various other ways like escaping single quotes etc but nothing really worked. I have very limited knowledge of PostgreSQL, so any help would be appreciated.
Postgres version: 13.1
Java version: 15
select * from items where cnt ## ?::jsonb
The thing on the right of the ## needs to be a jsonpath, not jsonb. So casting it to jsonb is clearly wrong. Try casting it to jsonpath instead.
For example, I'd like to run:
REGEXP_REPLACE("What's My Name?", "[^a-z0-9_\-]", "-");
and simply see what it returns, instead of doing a search against a DB Table. I tried to run it in the CLI and got
ERROR: syntax error at or near "REGEXP_REPLACE"
LINE 1: REGEXP_REPLACE("What's My Name?", "[^a-z0-9_\-]", "-")
(I'm trying to be generic- I'd like to be able to use this for other PSQL Aggregate Functions as well.)
Remember, this is SQL, so every output you get is a relation. Hence to calculate the result of a function, you need to run SELECT to retrieve the function's value.
Unfortunately, in many DBs, SELECT requires a table. In Oracle land, there's dual to work around this problem:
SELECT REGEXP_REPLACE('What''s My Name?', '[^a-z0-9_\-]', '-') FROM dual;
PostgreSQL, however, allows you to execute a SELECT query without having to specify a table:
SELECT REGEXP_REPLACE('What''s My Name?', '[^a-z0-9_\-]', '-');
Note that the string quote in SQL is ', not ". PostgreSQL uses double quotes to quote identifiers.
Side note: Not every function is an aggregate. An aggregate is a function that combines multiple values into a single output value. REGEXP_REPLACE() is just a normal string function.
Is there a way to run a single PSQL Aggregate Function without hitting a database table?
Yes, in PostgreSQL you can write a SELECT statement without a FROM part at all.
I was looking for a way to combine multiple returned rows into a single row on a db2 database (I have an application that can query a database, but will only work if a single row is returned). I found this solution which worked pretty well and was a lot easier than using recursive SQL. However, I ran into a problem when I tried to include a column that was set as TIMESTAMP instead of VARCHAR.
So how can I make this work if a column is a TIMESTAMP type?
Error:
SQL0440N No authorized routine named "XMLTEXT" of type "FUNCTION" having
compatible arguments was found. SQLSTATE=42884
SQL0440N No authorized routine named "XMLTEXT" of type "FUNCTION " having compatible arguments was found.
".
Example:
select xmlserialize(
xmlagg(
xmlconcat(
xmltext(column_name),
xmltext(':'),
xmltext(content),
xmltext(','),
xmltext(DATETIMESTAMP),
xmltext(',')
)
) as varchar(10000)
)
from
yourtable
Instead of the suggested CAST you could wrap the TOCHAR` function around the timestamp value:
select xmlserialize(
xmlagg(
xmlconcat(
xmltext(column_name),
xmltext(':'),
xmltext(content),
xmltext(','),
xmltext(TO_CHAR(DATETIMESTAMP)),
xmltext(',')
)
) as varchar(10000)
)
from
yourtable
If you are on a recent version of DB2 and have LISTAGG available I would recommend to use that function. It is much faster than converting the SQL input to XML types and then converting it back. It requires some CPU cycles due to all the official rules involved.
I'm using the persistent-postgresql library from Yesod, and I'd like to execute the following raw query:
SELECT * FROM utterance WHERE is_target IS NULL ORDER BY RANDOM() LIMIT 1000
to select 1000 random utterances with a NULL is_target. However, persistent generates the following SQL when I run my code through rawSql:
SELECT * FROM utterance WHERE is_target IS NULL ORDER BY RANDOM() LIMIT 1000"utterance"."id", "utterance"."message", "utterance"."is_target"
This generates an error in postgresql of syntax error at or near ""utterance"" at character 77.
What am I doing wrong?
I fixed this by using the following query instead:
SELECT ?? FROM utterance WHERE is_target IS NULL ORDER BY RANDOM() LIMIT 1000
rawSql doesn't work with column wildcards, because it enforces strong typing on returned data, so it's trying (and failing) to figure out where to put the column names. You need to explicitly list column names OR use some number of "??" placeholders in the statement and bind them at runtime like,
$ (Entity myType utterance, .... ) -> do ....
If you don't want strong typing, you probably also don't want to use Persistent; that's the entire reason it exists.