I have a specific column in a table, it shall contains only numbers in Nvarchar that have a length of 3. Unfortunately, some users wrote '12' but they should have written '012'. There were not enough validation at the time.
I need to fix that. Here is the logic I used :
UPDATE [Mandats_Approvisionnement].[dbo].[ARTICLE_ECOLE]
SET [UNIT_ADM] = STUFF(UNIT_ADM, 0, 0, '0')
WHERE LEN(UNIT_ADM) = 2;
The error goes like :
Cannot insert the value NULL into column 'UNIT_ADM', table
'Mandats_Approvisionnement.dbo.ARTICLE_ECOLE'; column does not allow
nulls. UPDATE fails.
I can't see where the problem is, I verified and all the records contain at least 2 characters, so the STUFF function cannot returns null as there are no NULL records in that table column [unit_adm]... How do I make it work ?
It should be stuff(UNIT_ADM,1,0,'0') as stuff returns null if the start position is 0.
Citing the documentation:
If the start position or the length is negative, or if the starting
position is larger than length of the first string, a null string is
returned. If the start position is 0, a null value is returned.
You could make this simpler by using
right('0' + UNIT_ADM, 3)
instead of stuff.
Related
I have this set of data that contains hyphens sign in my cell. My plan is to replace this hyphens sign to a number of 0 so that I can convert my column to numeric data type to do a calculation. The tricky part is where I only need to replace the cell that only contains hyphens sign (row 2 and row 3) without changing the negative value (row 6,7,8 and 9). I tried to use
regexp_replace("M1KW",'-','0','g')
function but it does change the negative value as well.
Any other special command that I can use ?
This is my sample data:
You seem to want to treat the string '-' as '0'. If so, you can directly replace the values:
update t
set mikw = '0'
where mikw = '-';
so that I can convert my column to numeric data type to do a calculation
You don't need to UPDATE all rows before being able to convert the data type to the correct one:
alter table the_table
alter mikw type numeric
using (case when mikw = '-' then 0 else mikw::numeric end);
That will do the "update" and the change of the data type in a single operation, rather than two.
Seems like the RIGHT function would be useful here, for isolating only instances where the hyphen is the last character.
Try this out:
UPDATE your_table
SET M1KW = 0
WHERE RIGHT(M1KW, 1) = '-';
This has been bothering me with my coding continuously and I can't seem to google a good workaround.
I have a number of columns which are data type nvarchar(255). Pretty standard I would assume.
Anyway, I want to run:
DELETE FROM Ranks WHERE ISNULL(INST,0) = 0
where INST is nvarchar(255). I am thrown the error:
Conversion failed when converting the nvarchar value 'Un' to data type int.
which is the first non null in the column. However, I don't care for this showing me the error means it's not null? - I just want to delete the nulls!
Is there something simple I'm missing.
Any help would be fab!
An expression may only be of one type.
Expression ISNULL(INST,0) involves two source types, nvarchar(255) and int. However, no type change happens at this point, because ISNULL is documented to return the type of its first argument (nvarchar), and will convert the second argument to that type if needed, so the entire original expression is equivalent to ISNULL(INST, '0').
Next step is the comparison expression, ISNULL(INST, '0') = 0. It again has nvarchar(255) and int as the source data types, but this time nothing can stop the conversion - in fact, it must happen for the comparison operator, =, to even work. According to the data type precedence list, the int wins, and is chosen as the resulting type of the comparison expression. Hence all values from column INST must be converted to int before the comparison = 0 is made.
If you
just want to delete the nulls
, then just delete the nulls:
DELETE FROM Ranks WHERE INST IS NULL
If for some reason you absolutely have to use isnull in this fashion, which there is no real reason for, then you should have stayed in the realm of strings:
DELETE FROM Ranks WHERE ISNULL(INST, '') = ''
That would have deleted null entries and entries with empty strings (''), just like the WHERE ISNULL(INST, 0) = 0 would have deleted null entries and entries with '0's if all values in INST could have been converted to int.
With ISNULL(INST,0) you are saying: If the string INST is null, replace it with the string 0. But 0 isn't a string, so this makes no sense.
With WHERE ISNULL(INST,0) = 0 you'd access all rows where INST is either NULL or 0 (but as mentioned a string is not an integer).
So what do you want to achieve? Delete all rows where INST is null? That would be
DELETE FROM ranks WHERE inst IS NULL;
I have a column that will always be 5 digits long, and each digit will always be a 1 or a 0. I need to put in my where clause to exclude when the second position is equal to 1. For example 01000 is to be excluded but 10010 is to be kept. I currently have:
WHERE (SUBSTRING(field, 2, 1) <> '1') or field IS NULL
How do do this without using the Substring function?
Edit:Also, the column is a varchar(10) in the database. Does this matter?
You could use the like operator to check that character directly:
WHERE field LIKE '_1%' OR field IS NULL
Use LEFT and RIGHT and then check that is 1 or not as below-
WHERE RIGHT(LEFT(field,2),1) <> '1' OR field IS NULL
No.
If 'field' is of a string type, you need to use string functions to manipulate it. SUBSTRING or some other flavor of it.
You can also convert it to binary and use bitwise AND operator but that won't solve the root issue here.
You are facing the consequences of someone ignoring 1NF.
There is a reason why Codd insisted that every "cell" must be atomic. Your's is not.
Can you separate this bitmap into atomic attribute columns?
I did a rather easy view to return only rows where there is number is CONTRACT_ID column. CONTRACT_ID has data type number(8).
CREATE OR REPLACE VIEW cid AS
SELECT *
FROM transactions
WHERE contract_id IS NOT NULL
AND LENGTH(contract_id) > 0;
View works just fine until I scroll down to row ~2950 where I get ORA-01722. Same thing happens if I want to export data to Excel, my file gets only ~2950 rows instead of expected ~20k.
Any idea what might be causing this and how to resolve this issue?
Many thanks!
You wrote too much SQL.. The following will provide all the results you require:
CREATE OR REPLACE VIEW cid AS
SELECT *
FROM transactions
WHERE contract_id IS NOT NULL
You can't LENGTH() a number - a number is either null or it's a value, so you don't need this kind of check.
Passing a number to LENGTH() will turn it into a string first, i.e. LENGTH(TO_CHAR(numbercolumn)). You don't even need a LENGTH() check for null strings, as to oracle NULL string and a zero length string are equivalent, and calling LENGTH() on an empty string or a null, will return null, not 0 (so LENGTH(myNullStr) = 0 doesnt work out; it's not comparing 0 = 0, it's comparing null = 0 and null compared with anything is always false).
The only time this seems to cause confusion is when the string columns in the table are CHAR types rather than VARCHAR types, and people forget that assigning an empty string to a CHAR causes it to become space padded out to the CHAR length hence, not a zero length string any more
First of all, you should remove redundant condition about length(), it's senseless. I'm not sure how it can produce such error, but check whether error disappered after it.
If no, replace star (*) to some field names, say, contract_id. If it will fix error - it would appoint that error source somewhere into removed fields (say, if generated column used).
I cannot imagine how error can be still alive after that, by if so, I'd tried to move it into other tablespace and add into fields list a call of logging function which stores rowid's of rows read - thus check which row produces error.
I have a stored procedure where it is able to update the 4 columns below as there are 4 parameters (1 parameter for each column with ClawbackID the only one that doesn't change).
Now there is no fixed amount of columns that can be updated, I may choose to update 1 column, or 3 columns or all 4 columns. So to reduce human error, I have a coalesce so that if the user enters in 'NULL' for a particular parameter whilst executing a procedure, the original amount stays.
Example for row 3 for 'ClawbackAmount', if I enter in NULL and execute, it will still display the 'ClawbackAmount' 900.54. Now the problem I have is that actually want to set this amount to 'NULL', but I don't want to lose the functionality that if I type in 'NULL' when executing my procedure that it keeps the old value.
My question is that is there a way or an idea you can think of where I type in NULL then the default values stays but if I type in something like '' then it will default to 'NULL'?
Or alternatively type in the word 'SAME' to keep the default value and then type in 'NULL' for a null value? Just ideas really to get around it?
Below is the code I have with the parameters included as they begin with #:
update clw
set clw.PaymentID = Coalesce(#PaymentID, clw.PaymentId)
,clw.ClawbackDate = Coalesce(#ClawbackDate, clw.ClawbackDate)
, clw.ClawbackPercent = Coalesce(#ClawbackPercent, clw.ClawbackPercent)
, clw.ClawbackAmount = Coalesce(#ClawbackAmount,clw.ClawbackAmount)
OUTPUT '[Fees].EBD.Clawback' 'TableName','ClawbackId', inserted.ClawbackId,
Core.updXMLFragment('PaymentId', inserted.PaymentId, deleted.PaymentId) +
Core.updXMLFragment('ClawbackDate', Convert(varchar(50),inserted.ClawbackDate, 112), Convert(varchar(50),deleted.ClawbackDate, 112)) +
Core.updXMLFragment('ClawbackPercent', inserted.ClawbackPercent, deleted.ClawbackPercent) +
Core.updXMLFragment('ClawbackAmount', inserted.ClawbackAmount, deleted.ClawbackAmount)
INTO #OutputList
from [Fees].EBD.Clawback clw
Where
ClawbackId = #ClawbackID
Below is the code for the execution as an example for row 3 if I want to make the desired change:
First Param is ClawbackID (this doesn't change but need it to know which row to manipulate.
Second Param is PaymentID which is NULL as want to keep the same
Third Param is Clawbackdate which is NULL as want to keep the same
Fourth Param is ClawbackPercent which needs to be 0.25
Last Param is ClawbackAmount which I need to set to NULL. This is an int field btw but leaving it NULL will keep the orginal amount displayed.
exec SupportAudit.BI.UpdateHotelClawback 28817, NULL, NULL, 0.25, NULL
I generally use some specific invalid value as an indicator the column should be set to NULL. In the case of ClawbackPercent and ClawbackAmount, -1 seems like a good candidate. The change would look like this:
...
, clw.ClawbackPercent = NullIf(Coalesce(#ClawbackPercent, clw.ClawbackPercent), -1)
, clw.ClawbackAmount = NullIf(Coalesce(#ClawbackAmount,clw.ClawbackAmount), -1)
...
For string parameters, '' (the empty string) might be an appropriate choice.