PostgreSQL: return message after count = 0 - postgresql

I have maybe easy question, but I'm completely stucked.
I have script
SELECT COALESCE(COUNT(id), 0) as MyFiels from table
It works fine and when I have zero value it shows 0.
But I want that instead of 0, I can see one line = "NO RESULTS" for example.
I tried:
SELECT COALESCE(to_char(COUNT(id), 'NO RESULT')) as MyFiels from table
And PostgreSQL shows error message:
ERROR: "E" is not supported
SQL state: 0A000
Where I'm incorrect? Any ideas?

I see what is the error, you are trying to use coalesce to convert 0 to string, and coalesce convert null to something. You need use a CASE
SELECT CASE WHEN COUNT(*) = 0 THEN 'NO RESULT'
ELSE CAST(COUNT(*) as TEXT)
END as field
FROM Table

Related

LPAD function errors when used in WITH variable in Redshift

Can you tell me why this is throwing an error in Redshift?
WITH Testing_PADDING AS (SELECT '12345678' AS column1)
SELECT LPAD(column1, 9,'0') FROM Testing_PADDING;
Here is the error I receive:
"Invalid operation: failed to find conversion function from "unknown" to text;"
Redshift can't determine data type from the context, so you need to explicitly set it
WITH Testing_PADDING AS (SELECT '12345678'::text AS column1)
SELECT
LPAD(column1, 9, '0')
FROM Testing_PADDING;
I suspect that one of your strings isn't being seen as text - likely the column1 text. (Sorry don't have a cluster up not to test)
Try:
WITH Testing_PADDING AS (SELECT '12345678'::text AS column1)
SELECT LPAD(column1, 9,'0'::text) FROM Testing_PADDING;

SQL Command failed with: ERROR: operator does not exist: character varying?

i am trying to get values from database by using following query
SELECT Distinct org.name AS org, sto.ad_org_id AS wh_nearstoredetails_id, sum(sto.qtyonhand) AS qty, pro.name AS product
FROM ad_org org, m_storage_detail sto, m_product pro
WHERE sto.ad_org_id::text = org.ad_org_id::text
AND (sto.m_locator_id::text IN ( select cast(m_locator.m_locator_id as text)
from m_locator,m_warehouse
where m_warehouse.isactive = cast('Y' as varchar)
and m_warehouse.em_ai_warehouseparent::text not like cast('' as text)
and m_warehouse.m_warehouse_id::text = m_locator.m_warehouse_id::text
and m_locator.isdefault = cast('Y' as varchar)))
AND sto.m_product_id::text = pro.m_product_id::text
AND sto.qtyonhand >= cast(1 as numeric)
AND sto.ad_org_id::text IN ( SELECT cast(m_warehouse.ad_org_id as text)
FROM m_warehouse
WHERE m_warehouse.em_ai_warehouseparent::text not like cast('' as text))
GROUP BY org.name,sto.ad_org_id,pro.name
ORDER BY org.name, pro.name;
after creating this i also created a class to call this query and get data but when i deploy my project i am getting following error
WARN - SQL Command failed with: ERROR: operator does not exist: character varying !
Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
please help to solve this issue.
i finally found the mistake what i made.
the problem in the above query is i'm trying to make type cast of null value
now i changed the condition to check 'is not null' than "not like ''"
and even i don't need to add cast operation it's useless.
anyways thanks for you response. :)

DB2 Merge using multiple columns in ON statement

I have a megre statement that does something like the following:
MERGE INTO TABLE_NAME1 tgt
USING (SELECT CONTRACTOR, TRACTOR, COL1, COL2 FROM TABLE_NAME2) src
ON src.CONTRACTOR = tgt.CONTRACTOR AND src.TRACTOR = tgt.TRACTOR
This is because a contractor can have multiple tractors. The table key is not used because it is an identity key only - auto number on insert.
The Merge runs OK when the table is empty, but when running it again it duplicates the rows where the tractor is null. So I tried:
ON ((src.CONTRACTOR = tgt.CONTRACTOR AND src.TRACTOR = tgt.TRACTOR)
OR (src.CONTRACTOR = tgt.CONTRACTOR AND tgt.TRACTOR IS NULL))
But this causes it to hang. Does DB2 have an issue comparing NULL to NULL?
"Does DB2 have an issue comparing NULL to NULL?" No, it does not. However, the result of such a comparison is unknown, in other words, it is neither true nor false:
$ db2 "select * from sysibm.sysdummy1"
IBMREQD
-------
Y
1 record(s) selected.
$ db2 "select * from sysibm.sysdummy1 where null = null"
IBMREQD
-------
0 record(s) selected.
$ db2 "select * from sysibm.sysdummy1 where null != null"
IBMREQD
-------
0 record(s) selected.
Without seeing your complete statement and sample data it's hard to provide a definite answer, but you may want to try instead:
...ON ((src.CONTRACTOR = tgt.CONTRACTOR AND src.TRACTOR = tgt.TRACTOR
AND tgt.TRACTOR IS NOT NULL))

Jasper-reports: Error: operator does not exist date = boolean

[EDIT: This problem was a result of a bug within version 3.7.6]
The following postgresql query is returning an error:
operator does not exist date = boolean.
I can't figure out why. Here is the postgresql code that is giving me the error:
select
c.source,
s.name,
s.grouping,
s.kli,
s.term_desc,
(s.population - s.online) as non_hb_pop,
s.online as hb_pop,
s.population as full_pop,
s.rep_date
from
dwh.rpt_cu_private_kli_summary s, dwh.rpt_sgmt_clients c
where
s.partner_id::integer = $P{rpt_cu}
and s.rep_date = $P{rpt_date_beg}
and s.userid=c.userid
group by
c.source, s.term_desc, s.name, s.grouping,
s.population, s.online, s.kli, s.rep_date
order by
s.grouping,
full_pop desc,
s.term_desc;
What does the above error message mean?
What is the value for $P{rpt_date_beg} ? That's where things go wrong. Check the real query, might be in the errorlog, and do some debugging. Maybe some quotes ' are missing around the date value.

need to translate specific t-sql case in pl/sql

Can anyone tell me how to translate the following T-SQL statement:
SELECT fileld1 = CASE
WHEN T.option1 THEN -1
ELSE
CASE WHEN T.option2 THEN 0
ELSE 1
END
END
FROM Table1 AS T
The point is I need to validate two different options from the table for a single field in the select statement..
I have tried to do somthing with an IF statement in pl/sql, but it just doesnt work for me:
SELECT IF T.option1 THEN -1
ELSE IF T.option2 THEN 0
ELSE 1
END
FROM Table1 AS T
I am not actually sure how to write IF statement inside the SELECT statement..
And also, I need to do it INSIDE the select statement because I am constructing a view.
Use:
SELECT CASE
WHEN T.option1 = ? THEN -1
WHEN T.option2 = ? THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
I can't get your original TSQL to work - I get:
Msg 4145, Level 15, State 1, Line 4
An expression of non-boolean type specified in a context where a condition is expected, near 'THEN'.
...because there's no value evaluation. If you're checking if the columns are null, you'll need to use:
SELECT CASE
WHEN T.option1 IS NULL THEN -1
WHEN T.option2 IS NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
...or if you need when they are not null:
SELECT CASE
WHEN T.option1 IS NOT NULL THEN -1
WHEN T.option2 IS NOT NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
CASE expressions shortcircuit - if the first WHEN matches, it returns the value & exits handling for that row - so the options afterwards aren't considered.
If I remember correctly, PL/SQL also supports the case. You just would have to move the column alias from "field1=" before the expression to "AS filed1" after the expression.