I'm trying to get empty "text" fields from my table which I cleared manually with pgadmin.
Initially in those fields was '' and I can query them like this:
SELECT mystr, mystr1 FROM mytable WHERE mystr='' or mystr1=''
But that not work if I delete text from them and leave cells blank.
How to write query to get those '' and clear cells together in result?
Or clear cells alone?
SELECT mystr, mystr1
FROM mytable
WHERE COALESCE(mystr, '') = ''
OR COALESCE(mystr1, '') = ''
;
Explanation: the coalesce(a,b,c, ...) function traverses the list a,b,c,... from left to right and stops at the first non-null element. a,b,c can be any expression (or constant), but must yield the same type (or be coercable to the same type).
Related
I'm using postgresql 11, I have a jsonb which represent a row of that table, it's look like
{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com",...,"thirdpartyauthenticationkey":{}}
is there any method that I could gather all the "values" of the jsonb into a string which is separated by ',' and without the keys?
The string I want to obtain with the jsonb above is like
(test, Root, 0, superadmin#ae.com, ..., {})
I need to keep the ORDER of those values as what their keys were in the jsonb. Could I do that with postgresql?
You can use the jsonb_populate_record function (assuming your json data does match the users table). This will force the text value to match the order of your users table:
Schema (PostgreSQL v13)
CREATE TABLE users (
userid text,
rolename text,
loginerror int,
email text,
thirdpartyauthenticationkey json
)
Query #1
WITH d(js) AS (
VALUES
('{"userid":"test", "rolename":"Root", "loginerror":0, "email":"superadmin#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb),
('{"userid":"other", "rolename":"User", "loginerror":324, "email":"nope#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb)
)
SELECT jsonb_populate_record(null::users, js),
jsonb_populate_record(null::users, js)::text AS record_as_text,
pg_typeof(jsonb_populate_record(null::users, js)::text)
FROM d
;
jsonb_populate_record
record_as_text
pg_typeof
(test,Root,0,superadmin#ae.com,{})
(test,Root,0,superadmin#ae.com,{})
text
(other,User,324,nope#ae.com,{})
(other,User,324,nope#ae.com,{})
text
Note that if you're building this string to insert it back into postgresql then you don't need to do that, since the result of jsonb_populate_record will match your table:
Query #2
WITH d(js) AS (
VALUES
('{"userid":"test", "rolename":"Root", "loginerror":0, "email":"superadmin#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb),
('{"userid":"other", "rolename":"User", "loginerror":324, "email":"nope#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb)
)
INSERT INTO users
SELECT (jsonb_populate_record(null::users, js)).*
FROM d;
There are no results to be displayed.
Query #3
SELECT * FROM users;
userid
rolename
loginerror
email
thirdpartyauthenticationkey
test
Root
0
superadmin#ae.com
[object Object]
other
User
324
nope#ae.com
[object Object]
View on DB Fiddle
You can use jsonb_each_text() to get a set of a text representation of the elements, string_agg() to aggregate them in a comma separated string and concat() to put that in parenthesis.
SELECT concat('(', string_agg(value, ', '), ')')
FROM jsonb_each_text('{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com","thirdpartyauthenticationkey":{}}'::jsonb) jet (key,
value);
db<>fiddle
You didn't provide DDL and DML of a (the) table the JSON may reside in (if it does, that isn't clear from your question). The demonstration above therefore only uses the JSON you showed as a scalar. If you have indeed a table you need to CROSS JOIN LATERAL and GROUP BY some key.
Edit:
If you need to be sure the order is retained and you don't have that defined in a table's structure as #Marth's answer assumes, then you can of course extract every value manually in the order you need them.
SELECT concat('(',
concat_ws(', ',
j->>'userid',
j->>'rolename',
j->>'loginerror',
j->>'email',
j->>'thirdpartyauthenticationkey'),
')')
FROM (VALUES ('{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com","thirdpartyauthenticationkey":{}}'::jsonb)) v (j);
db<>fiddle
I'm trying to decipher another programmer's code who is long-gone, and I came across a select statement in a stored procedure that looks like this (simplified) example:
SELECT #Table2.Col1, Table2.Col2, Table2.Col3, MysteryColumn = CASE WHEN y.Col3 IS NOT NULL THEN #Table2.MysteryColumn - y.Col3 ELSE #Table2.MysteryColumn END
INTO #Table1
FROM #Table2
LEFT OUTER JOIN (
SELECT Table3.Col1, Table3.Col2, Col3 = SUM(#Table3.Col3)
FROM Table3
INNER JOIN #Table4 ON Table4.Col1 = Table3.Col1 AND Table4.Col2 = Table3.Col2
GROUP BY Table3.Col1, Table3.Col2
) AS y ON #Table2.Col1 = y.Col1 AND #Table2.Col2 = y.Col2
WHERE #Table2.Col2 < #EnteredValue
My question, what does the fourth column of the primary selection do? does it produce a boolean value checking to see if the values are equal? or does it set the #Table2.MysteryColumn equal to some value and then inserts it into #Table1? Or does it just update the #Table2.MysteryColumn and not output a value into #Table1?
This same thing seems to happen inside of the sub-query on the third column, and I am equally at a loss as to what that does as well.
MysteryColumn = gives the expression a name also called a column alias. The fact that a column in the table#2 also has the same name is besides the point.
Since it uses INTO syntax it also gives the column its name in the resulting temporary table. See the SELECT CLAUSE and note | column_alias = expression and the INTO CLAUSE
I need to further refine my stored proc resultset from this post, I need to filter my resultset to display only records where emailaddr is NULL (meaning display only records that have Invoice_DeliveryType value of 'N' ).
Among numerous queries, I have tried:
select
Invoice_ID, 'Unknown' as Invoice_Status,
case when Invoice_Printed is null then '' else 'Y' end as Invoice_Printed,
case when Invoice_DeliveryDate is null then '' else 'Y' end as Invoice_Delivered,
(case when Invoice_DeliveryType <> 'USPS' then ''
when exists (Select 1
from dbo.Client c
Where c.Client_ID = SUBSTRING(i.Invoice_ID, 1, 6) and
c.emailaddr is not null
)
then 'Y'
else 'N'
end)
Invoice_ContactLName + ', ' + Invoice_ContactFName as ContactName,
from
dbo.Invoice
left outer join
dbo.fnInvoiceCurrentStatus() on Invoice_ID = CUST_InvoiceID
where
CUST_StatusID = 7
AND Invoice_ID = dbo.Client.Client_ID
AND dbo.client.emailaddr is NULL
order by
Inv_Created
but I get an error
The conversion of the nvarchar value '20111028995999' overflowed an int column
How can I get the stored procedure to only return records with DeliveryType = 'N' ?
Trying selecting the stored proc results into a temp table, then select
* from #TempTable
We could really do with a schema definition to get this problem resolved.
It appears that there is an implicit conversion occurring within one of your case statements, but without the schema def's it's difficult to track down which one.
You can't safely mix datatypes in CASE expressions, unless you are absolutely sure that any implicit conversions will work out OK you should make the conversions explicit.
Judging by the error message seeming to include something that could be a date represented as a string(20111028) plus some kind of other data ?time?(995999) it may be something to do with Invoice_DeliveryDate, but this is a shot in the dark without more details.
I've been given a table with a few fields that hold comma-separated values (either blank or Y/N) like so (and the field name where this data is stored is People_Notified):
Y,,N,
,Y,,N
,,N,Y
Each 'slot' relates to a particular field value and I need to now include that particular field name in the string as well (in this case Parent, Admin, Police and Medical) but inserting a "N" if the current value is blank but leaving the existing Y's and N's in place. So for the above example, where there are four known slots, I would want a tsql statement to end up with:
Parent=Y,Admin=N,Police=N,Medical=N
Parent=N,Admin=Y,Police=N,Medical=N
Parent=N,Admin=N,Police=N,Medical=Y
I tried to use a combination of CHARINDEX and CASE but haven't figured a way to make this work.
js
Although a bit messy, in theory can be done in one statement:
select
'Parent=' +stuff((stuff((stuff(
substring((replace(
(','+(replace((replace(#People_Notified,',,,',',N,N,')),',,',',N,'))+','),',,',',N,')),2,7),7,0,
'Medical=')),5,0,'Police=')),3,0,'Admin=')
broken down is easier to follow:
declare #People_Notified varchar(100)=',,Y,Y' -- test variable
-- Insert Ns
set #People_Notified= (select replace(#People_Notified,',,,',',N,N,')) -- case two consecutive missing
set #People_Notified= (select replace(#People_Notified,',,',',N,')) -- case one missing
set #People_Notified= (select replace((','+#People_Notified+','),',,',',N,')) -- case start or end missing
set #People_Notified= substring(#People_Notified,2,7) -- remove extra commas added previously
-- Stuff the labels
select 'Parent=' +stuff((stuff((stuff(#People_Notified,7,0,'Medical=')),5,0,'Police=')),3,0,'Admin=')
If you're able to use XQuery in SQL Server, I don't think you need to get too complex. You could do something like this:
SELECT CONVERT(XML, REPLACE('<pn>' + REPLACE(People_Notified, ',', '</pn><pn>') + '</pn>', '<pn></pn>', '<pn>N</pn>')).query('
concat("Parent=", data(/pn[1])[1], ",Admin=", data(/pn[2])[1], ",Police=", data(/pn[3])[1], ",Medical=", data(/pn[4])[1])
')
FROM ...
Explanation: Construct an XML-like string out of the original delimited string by replacing commas with closing and opening tags. Add an opening tag to the start and a closing tag to the end. Replace each empty element with one containing "N". Convert the XML-like string into actual XML data so that you can use XQuery. Then just concatenate what you need using concat() and the right indexes for the elements' data.
Here's one way to do it:
;WITH cteXML (Id, Notified)
AS
(
SELECT Id,
CONVERT(XML,'<Notified><YN>'
+ REPLACE([notified],',', '</YN><YN>')
+ '</YN></Notified>') AS Notified
FROM People_Notified
)
select id,
'Parent=' + case Notified.value('/Notified[1]/YN[1]','varchar(1)') when '' then 'N' else Notified.value('/Notified[1]/YN[1]','varchar(1)') end + ',' +
'Admin=' + case Notified.value('/Notified[1]/YN[2]','varchar(1)') when '' then 'N' else Notified.value('/Notified[1]/YN[2]','varchar(1)') end + ',' +
'Police=' + case Notified.value('/Notified[1]/YN[3]','varchar(1)') when '' then 'N' else Notified.value('/Notified[1]/YN[3]','varchar(1)') end + ',' +
'Medical=' + case Notified.value('/Notified[1]/YN[4]','varchar(1)') when '' then 'N' else Notified.value('/Notified[1]/YN[4]','varchar(1)') end Notified
from cteXML
SQL Fiddle
Check this page out for an explanation of what the XML stuff is doing.
This page has a pretty thorough look at the various ways you can split a delimited string into rows.
I'm writing some triggers to check if an arrtibute of a newly create tuple is present in another table. What is the best way to check this?
IF (SELECT * FROM TABLEB where NEW.Attribute = Attribute) = NULL THEN
return NULL
END IF
Is there a better way? And does a Select that returns nothing = NULL or empty set?
Use IF EXISTS (SELECT * FROM TABLEB where NEW.Attribute = Attribute).
An empty rowset isn't the same as NULL, which represents an empty cell of a row. Your syntax would only be valid if the query only selected one row, in which case PostgreSQL will allow use of comparison operators against the top cell returned, which counts as NULL if none are returned.