I want to convert null values to ' '. But when I use this code I got null values as 'NULL':
SELECT NVL(column_a, ' ') FROM table_a
If your GUI displays "NULL" for those values, it is the GUI setting, not Oracle value. Set it to something else (e.g. nothing, in your case).
Related
Using SQL Server, I would like to have a field print out as blank rather than 'null'. The query is to first pick up phone number from one table - if null then it picks up from another table. If both are null, then I would like to have it return ' ' (blank) rather than 'null'.
I have tried multiple things in the 2nd line but still get nulls instead of blanks to print.
SELECT case when dbo.vwPersonDistinctPhone.phone IS NULL THEN PERSONAL_PHONE_NUMBER
when (dbo.vwPersonDistinctPhone.phone is null and PERSONAL_PHONE_NUMBER is null) then ' '
else dbo.vwPersonDistinctPhone.phone END AS 'phone',
i dont think you need the second when, you should be able to just to do this, there is a isnull function in sql server that if the value is null then it replaces it with the second parameter. So in this case if personal_phone_number is null then it will be '' or personal_phone_number if is not.
SELECT case when dbo.vwPersonDistinctPhone.phone IS NULL THEN ISNULL(PERSONAL_PHONE_NUMBER, '') else dbo.vwPersonDistinctPhone.phone END AS 'phone',
I am using LISTAGG() function in my select statement in a procedure such as
SELECT DISTINCT REPLACE(LISTAGG(a.student1||':'||a.score||'+')
WITHIN GROUP ( ORDER BY a.roll_no) OVER (PARTITION BY a.class)
If my select statement has not null values then i get
for eg: ABC:100
But if the select is empty then i get
for eg: :
I wanted it to be null if there are no rows selected.
The problem is that the expression you're aggregating returns a non-NULL value whether or not the values you're concatenating are NULL. My guess is you want something like
listagg(case when a.student1 is not null
then a.student1||':'||a.score||'+'
else null
end)
If you can have a null value for student1 but a non-NULL value for score, you'd need to adjust the case statement to specify what you want to happen in that case (do you want the ":" and the "+"? Just the "+"?)
Well, your REPLACE is incomplete. Also, is '+' really supposed to be concatenated? What string separates values, then?
REPLACE (
LISTAGG (a.student1 || ':' || a.score, '+') --> removed || for the + sign
WITHIN GROUP (ORDER BY a.roll_no)
OVER (PARTITION BY a.class),
':', '') --> missing arguments for REPLACE
If that's still not what you asked, please, provide sample test data and desired output.
I have seen several similar questions but none cover what I need. I need to put another THEN statement after the first one. My column contains int's. When it returns NULL I need it to display a blank space, but when I try the below code, I just get '0'.
CASE
WHEN Column1 IS NULL
THEN ''
ELSE Column1
END
If I try to put a sting after THEN then it tells me that it cannot convert it from int. I need to convert it to varchar and then change its output to a blank space afterwards, such as:
e.g.
CASE
WHEN Column1 IS NULL
THEN CONVERT(varchar(10), Column1)
THEN ''
ELSE Column1
END
Is there a way of doing this?
Thanks
Rob
A case expression returns a single value -- with a given type. If you want a string result, then you need to be sure that all paths in the case return strings:
CASE WHEN Column1 IS NULL
THEN ''
ELSE CAST(Column1 AS VARCHAR(255))
END
This is more simply written using COALESCE():
COALESCE(CAST(Column1 as VARCHAR(255)), '')
You cannot display an integer as a "blank" (other than using a NULL value).
I have a very but tricky question for you guys. So, listen I have a field with spaces and numbers in one of my table columns. The key part is transform the content in a decimal field. The drawback is basically that for some rows I could get something like:
' 1584.00 '
' 156546'
'545.00 '
' '
So, to clean up my column, I have done a LTRIM and RTRIM so spaces gone. So now for a couple of records where the record were just spaces the new content is ''. Finally I need to convert this result to a decimal.
Issue: The thing is that for field that contend just the spaces the new result is '' and I'm not able to apply a REPLACE on this because it's a blank and the code below doesn't work:
SELECT REPLACE('','','0')
-- Final current verison
SELECT CAST(COALESCE(REPLACE(REPLACE([Gross_Weight],' ','0'),',',''),'0') AS DECIMAL(13,3))
How could I figure it out?
thanks so much
SELECT COALESCE(NULLIF(MyColumn, ''), 0)
This has the side-effect that you will also turn NULL values into 0, which you might not want. If that's a problem then a simple CASE statement should do the trick:
SELECT CASE WHEN MyColumn = '' THEN 0 ELSE CAST(MyColumn AS DECIMAL(10, 4)) END
Obviously you'll also have to incorporate any other manipulations that you're already doing.
No need for replace, just concatenate a zero to your column, like
SELECT RTRIM('0' + LTRIM(column))
I presume your data is in a table.
Lets call this table 'DATA' and the column 'VALUE'
Then you might use the below query
UPDATE DATA SET VALUE = 0 where VALUE = ''
To select the value do the below
select case ltrim(rtrim([Gross_Weight])) when ''
THEN 0
ELSE ltrim(rtrim([Gross_Weight])) END
Let me know if i get the requirement wrong.
I believe what I'm asking here is possible, but I haven't find a way yet :
Some cells in the result of my SQL SELECT-FROM-WHERE query are blank, and in DbVisualizer, (null) is written inside. I'd like to display a blank cell instead.
I've already tried with CASE-WHEN and the NVL operator, but it won't let me replace it by a blank '', I'm forced to use some ' ' or 'message'.
I know I could just delete these spaces or messages with Excel later, but I'd like to know if there is a way to do it directly with DbVisualizer, instead of this workaround.
EDIT: Here is what my request looks like :
SELECT *things*,
CASE WHEN
(SELECT COUNT(*) FROM table d2 WHERE *join-condition* AND *other condition*) = 1
THEN
(*sub-select query*)
ELSE
''
END
AS NAME,
*other things*
FROM table d1
WHERE *something*
Thanks a lot !
Did you try standard SQL function coalesce(), as below ?
SELECT COALESCE(columnName, '') AS ColumnName FROM tableName;
Syntax:
COALESCE (expr1, expr2)
is equivalent to:
CASE WHEN expr1 IS NOT NULL THEN expr1 ELSE expr2 END
Similarly,
COALESCE (expr1, expr2, ..., exprn), for n>=3
is equivalent to:
CASE WHEN expr1 IS NOT NULL THEN expr1
ELSE COALESCE (expr2, ..., exprn) END
Above examples are from Database SQL Language Reference
The problem in your query is the following ELSE part of the CASE expression:
ELSE
''
In Oracle, an empty string is considered as NULL value. So, all you need to do is use something else instead of ''.
For example, to use a space instead of NULL:
ELSE
' '
Update The issue is the DbVisualizer tool. OP is on version 8.0.12. Prior to version 9.2.8 it cannot show NULL as an empty string. However, as discussed in this forum, it has been fixed in DbVisualizer 9.2.8.
Standard SQL provides COALESCE(expr1, expr2, ...) as suggested by #Shishir.
COALESCE() takes a variable amount of arguments and returns the first expression that is NOT NULL
MySQL also provides IFNULL(expr1,expr2), which returns expr2 when expr1 IS NULL
Examples
SELECT
COALESCE(field1, ''),
COALESCE(field1, field2, field3)
IFNULL(field1, ''),
IFNULL(field1, field2)
FROM table