T-SQL (SS2K8) :: Field Has No Value But Is Not NULL Or Empty?
Aug 13, 2015
I added a new field to an existing ETL process which uses SSIS to ingest a CSV file. The new field in the file, Call_Transaction_ID, will not always be populated for every record and so can be NULL or empty for certain records.
Here's the problem:After the file is extracted into a staging table, the Call_Transaction_ID field is showing blank or empty when it has no ID for that particular record. The problem is when I try to then ETL this data into a fact table - I'm trying to set the Call_Transaction_ID field to -1 if it is NULL or empty, however SQL Server doesn't see the field as empty even though there is no value in the field so -1 will NEVER return.
Using a WHERE DATALENGTH(Call_Transaction_ID) = 0 returns 0 records, again because SQL Server doesn't see the field as empty or NULL.
What do I do now to get around this? How do I fix it?
declare @user varchar(30) = '' if(@user is not null or @user <> '') BEGIN print 'I am not empty' END ELSE BEGIN print 'I am empty' ENd
The output should be 'i am empty' but when i execute this i am getting ' i am not empty'. even i did browse through but i don't find the difference in my logic.
i have a trigger on a table right now... when fields are inserted, theres a text field inserted and i want to check if that text field = '' (the empty string, not NULL) and if it doesn't equal that, then perform some row updates on other tables, but if it is empty, to not do anything else in the trigger... right now i have this:
Code:
IF ((SELECT Note FROM XATPoDetail WHERE ReqNbr = (SELECT ReqNbr FROM Inserted)) LIKE(''))
Note is the text field, XATPoDetail is the table where its being inserted into. I had to do the select FROM the table because it wouldn't let me select a text data type from the "Inserted" virtual table
but it tells me me "Error 279: The text, ntext, and image data types are invalid in this subquery or aggregate expression"
i have a trigger on a table right now... when fields are inserted, theres a text field inserted and i want to check if that text field = '' (the empty string, not NULL) and if it doesn't equal that, then perform some row updates on other tables, but if it is empty, to not do anything else in the trigger... right now i have this:
IF ((SELECT Note FROM XATPoDetail WHERE ReqNbr = (SELECT ReqNbr FROM Inserted)) LIKE(''))
Note is the text field, XATPoDetail is the table where its being inserted into. I had to do the select FROM the table because it wouldn't let me select a text data type from the "Inserted" virtual table
but it tells me me "Error 279: The text, ntext, and image data types are invalid in this subquery or aggregate expression"
Hi, What is the difference updating a null value to char/varchar type column
versus empty string to char/varchar type column?Which is the best to do and why? Could anyone explain about this?
Example:
Table 1 : tCountry - Name varchar(80) nullable Table 2 :tState - Name char(2) nullable Table 3 :tCountryDetails - countryid,state (char(2) nullable) - May the country contain state or no state So,when the state is not present for the country ,i have two options may be - null,'' tCountryDetails.State = '' or tCountryDetails.State = null?
I would like to force a column to be null all the time. I cannot alter the table structure or alter the code that inserts data.
create table dbo.tblCustomer ( CID int IDENTITY(1,1) not null, Fnamevarchar(20) not null, Lnamevarchar(20) not null, Extravarchar(20) null
[Code] ....
So when this is executed the field Extra is always NULL
INSERT INTO tblCustomer (Fname, Lname, Extra) VALUES ('bob', 'smith', 'ignore'), ('jane', 'doe', 'empty') update dbo.tblCustomer set Extra = 'something'
If I've understood After triggers correctly the data will be written and the trigger will fire and overwrite. To avoid 2 writes
I could create an INSTEAD OF trigger
CREATE TRIGGER TR_I_Customer ON tblCustomer INSTEAD OF INSERT AS BEGIN SET NOCOUNT ON INSERT INTO tblCustomer (Fname, Lname, Extra) SELECT Fname, Lname, NULL FROM Inserted END
This will not write the "extra" field twice. However if a new Nullable column were added; it would be v.easy to forget to update the Instead Of trigger. Everything would still work OK but I would be effectively ignoring the new column as well.
What I would like in the instead of trigger is do something like this...
UPDATE INSERTED SET Extra=NULL
Continue with insert without supplying column /value list.
What would be the best way of achieving this, trigger is the only way I could think of?
hi,my structure table in database:Amount float(53) not null default 0when i try to run his script:alter table ABC alter column Amount float(53) nullit can only set the Amount to allow null, but can't set the defaultvalue to empty.anyone know how to set the field to allow null and default set toempty, no value.thanks
I have a query that returns the appropriate values I need, however there is one field I'd like to add and utilize but my problem is I only want to use it if it contains data.
If I filter it with IS NOT NULL it returns all the records, including the empty records. The field is simply empty, and doesn't come back as NULL. If I filter it with =' ' , it shows all the records with the empty records only.
I need to do the opposite, be able to filter it only if it's not empty.
I've inherited a terribly designed database. When cells in the tables have nothing in them, rather than being NULL, they're just empty. So now I can't use COALESCE...
Is there a way for COALESCE to check if a cell is empty instead of NULL? And if not, is there a way to get around this?
I need to find all empty files in the database (SQL Server 2008R2 SP2) The files become empty after the archival of a partitioned tables.
I was trying this:
select f.name, * from sysfiles f (nolock) left join sys.filegroups fg (nolock) on f.name = fg.name left join sys.indexes i (nolock) on i.data_space_id = fg.data_space_id left join sys.all_objects o (nolock) ON i.[object_id] = o.[object_id] where i.name is NULL and o.name is NULL
Did not work.
My file names are the same as the filgroup names containing the file, this is why I was joining by name.
I need to check in my Stored procedure if the information passed is null or empty so I can decided to insert the new value or keep the old. How do I accomplish this please in T-SQL. Thanks in advance.
Hi: Trying to insert null value into sql table, but not working, if I use: if (strMyText.Length == 0) command.Parameters.Add("@Text", DBNull.Value); // or using:("@Text", null), or using:("@Text", DBNull) else command.Parameters.AddWithValue("@Text", strMyText); When I go back to table, I see the value is: 'NULL', has single quotation mark, suppose to be: NULL Where is the problem? Thanks a lot. Jt
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Well met,
Let's say I have a web form that allows users to insert and update records in a SQL database. Is it better to set empty web controls (textbox, etc.) to DBNull or let it go as an empty string into the database?
Hi all, I have some columns in my database which allows null. I want to know if leaving the field to be NULL or storing an empty string into the field, which will take up more space?? if the field type is varchar(100)
I've have about 100 tables, for some reasons, column values that are originally NULL was inserted as emtpy string. So, I am wondering if I can write JUST ONE SQL (hopefully don't have to specify the field names in the SQL as well) for each table so that all the empty strings will be converted back to NULL.
SELECT DISTINCT S.EnrollNo ,S.Name ,ET.Descriptions AS EventName ,SA.Name AS AttendStudent ,'' AS AttendFaculty FROM StudentEvent SE INNER JOIN SStudent S ON SE.PresentatorID = S.StudentID
Hello,I'm a beginner in SQL and I have been searching through the SQL Cookbook and Google but I can't seem to find an example of what I want to do. I want to create a report that will return names and emails using two of my tables. I want to use the email in my primary table in the select but if it is null or empty I want to replace it with an email from my secondary table. Below is what I would like to do but I got a syntax error with it in SQL Server 2000. SELECT MemberID As ID, MemberFirstName As FirstName, MemberLastName As LastName, (IF MemberEmail = '' THEN SELECT TOP 1 OtherEmail FROM OtherTable WHERE OtherID = MemberID) As EmailFROM PrimaryTableThanks for your time.Jason
I have always (or at least intended to) treat NULL and empty strings separately in my SQL querying history. Now I have run across something that mystifies me (but probably shouldn't) that I would like an explanation for.
Consider this bit o' code:
DECLARE @ORDER CHAR(10) SET @ORDER= ( SELECT NULL ) IF @ORDER <> '' PRINT 'Not an empty string'
IF @ORDER IS NULL PRINT 'It is NULL'
Run this and you will get:
It is NULL
I was expecting:
Not an empty string It is NULL
Why is NULL not passing the 'not an empty string' test? In other words, how does NULL = '' ? Is NULL cast to an empty string for this comparison?
Hi,I run a stored procedure with a parameter given from a text box in an accessadp. If the text box is empty then what is passed to the parameter? I can'tseem to get it to flag up as either null, or 0 length.Any tips?Cheers,Chris
HI, I am using XmlDataDocuments returned by webservices and query in the reports to populate the reports.
The issue I have is if the dataset used to populate the XML document has any nulls or empty spaces in any field the whole column or row is missing in the data generated by my query in the Reports. Sometimes the whole data is not being returned to the reports.
I have tested the webservice with sample data and it works well, returns data.
I use the ISNULL() in my stored procedures to avoid nulls but with empty strings, replacing them with a default value in the managed code is expensive and slows down the reports. Is there some feature I am missing because of which nulls and empty strings are causing this problem.
Hi all,I have this code that I use for my Search function:SELECT DISTINCT [MUSIC_TITLE], [MUSIC_ORIGINAL_SINGER], [MUSIC_PERFORMER]FROM t_musicWHERE (@MUSIC_TITLE IS NULL OR [MUSIC_TITLE] LIKE '%' + @MUSIC_TITLE + '%') AND (@MUSIC_ARTIST IS NULL OR ([MUSIC_ORIGINAL_SINGER] LIKE '%' + @MUSIC_ARTIST + '%' OR [MUSIC_PERFORMER] LIKE '%' + @MUSIC_ARTIST + '%')) But right now if I don't enter anything in one of the textbox (2 have two, either of them can be left empty), the above Sql statement doesn't return anything since ADO.NET can't tell an empty textbox and treat it at null... So anyone please help me how to detect an empty textbox and set that to null for the above SQL statement to work. (It work in SQL Manager Studio, when I set one of the parameter = null.) I'm very new to ASP.NET stuffs, so if someone can help me to convert that function to code-behind and help me to call it from the .aspx, that would be even better as I don't want to put the code in my .aspx page... But I'm not quite there yet. Thank you all,Kenny.
I am using the following query to calculate date differences:select ..........DATEDIFF(d, recruitment_advertising.advertising_date, career_details.RTS_Email AS Datetime) AS Ad_to_RTS_days FROM .....I have stored all my dates as NVARCHAR because of the issues with localization.If the value is an empty String my output is eg: -38700. which is way off and incorrect. Some of the values in my table are NULL and they produce the correct result.Is there a T-SQL statement to replace empy Strings with the NULL value in my tables.I'd like to use it as a trigger when inserting or updating to convert empty strings to NULLbefore the values are inserted.Thanks guys.
We are writing a C application that is using ODBC to insert recordsinto a database. We have a NOT NULL column that can legitimately havean empty value, i.e. we know the value and it is empty (i.e. a zerolength string).We are using SQLBindParameter() to bind a variable to theparameterized insert statement <<in the form: INSERT INTO table VALUES(?, ?, ?)>>. We are using SQLExecDirect() to process the SQL.We are running into the problem where ODBC is converts the empty (zerolength) string into a NULL value and this errors due to the fact thatthe column is defined as NOT NULL.We do not want to redefine the column as NULL, becasue myunderstanding of the correct usage of a NULL column is to indicatethat a value is unknown or meaningless... in our case we know thevalue (it is empty) and an empty value has meaning within ourapplication.I'm sure that this issue has been seen and address thousands(millions?) of times... any guidance would be appreciated.
Let's say I have three fields in a table like this...
Name
Tell us about cats
Tell us about dogs
Now I have two records.
Name Billy Bob
Tell us about cats I do not have any Cats
Tell us about dogs "null"
Name Joe Slick
Tell us about cats "null"
Tell us about dogs they sure chase Cats a lot.
I want my report to generate like this:
Name Billy Bob
Tell us about cats I do not have any cats
Name Joe Slick
Tell us about dogs they sure chase cats allot.
How do I omit null fields in a report including the field description? I am pretty flexible and I am willing to explore using ASP.Net, asp, html, VS2005 ? Or please tell me a program to use. I have a lot of reports to create. The data base is MS SQL 2005. The reports need to be published to the web. Can anyone suggest the best method?
