How do I check if a SQL Server text column is empty?
Sql ServerSql Server-2005SqldatatypesNotnullEmptydatatextSql Server Problem Overview
I am using SQL Server 2005. I have a table with a text column and I have many rows in the table where the value of this column is not null, but it is empty. Trying to compare against '' yields this response:
>The data types text and varchar are incompatible in the not equal to operator.
Is there a special function to determine whether the value of a text column is not null but empty?
Sql Server Solutions
Solution 1 - Sql Server
where datalength(mytextfield)=0
Solution 2 - Sql Server
ISNULL(
case textcolum1
WHEN '' THEN NULL
ELSE textcolum1
END
,textcolum2) textcolum1
Solution 3 - Sql Server
Actually, you just have to use the LIKE operator.
SELECT * FROM mytable WHERE mytextfield LIKE ''
Solution 4 - Sql Server
To get only empty values (and not null values):
SELECT * FROM myTable WHERE myColumn = ''
To get both null and empty values:
SELECT * FROM myTable WHERE myColumn IS NULL OR myColumn = ''
To get only null values:
SELECT * FROM myTable WHERE myColumn IS NULL
To get values other than null and empty:
SELECT * FROM myTable WHERE myColumn <> ''
And remember use LIKE phrases only when necessary because they will degrade performance compared to other types of searches.
Solution 5 - Sql Server
SELECT * FROM TABLE
WHERE ISNULL(FIELD, '')=''
Solution 6 - Sql Server
Use the IS NULL operator:
Select * from tb_Employee where ename is null
Solution 7 - Sql Server
I know this post is ancient but, I found it useful.
It didn't resolve my issue of returning the record with a non empty text field so I thought I would add my solution.
This is the where clause that worked for me.
WHERE xyz LIKE CAST('% %' as text)
Solution 8 - Sql Server
Use DATALENGTH method, for example:
SELECT length = DATALENGTH(myField)
FROM myTABLE
Solution 9 - Sql Server
Instead of using isnull
use a case
, because of performance it is better the case.
case when campo is null then '' else campo end
In your issue you need to do this:
case when campo is null then '' else
case when len(campo) = 0 then '' else campo en
end
Code like this:
create table #tabla(
id int,
campo varchar(10)
)
insert into #tabla
values(1,null)
insert into #tabla
values(2,'')
insert into #tabla
values(3,null)
insert into #tabla
values(4,'dato4')
insert into #tabla
values(5,'dato5')
select id, case when campo is null then 'DATA NULL' else
case when len(campo) = 0 then 'DATA EMPTY' else campo end
end
from #tabla
drop table #tabla
Solution 10 - Sql Server
I would test against SUBSTRING(textColumn, 0, 1)
Solution 11 - Sql Server
Are null and an empty string equivalent? If they are, I would include logic in my application (or maybe a trigger if the app is "out-of-the-box"?) to force the field to be either null or '', but not the other. If you went with '', then you could set the column to NOT NULL as well. Just a data-cleanliness thing.
Solution 12 - Sql Server
I wanted to have a predefined text("No Labs Available") to be displayed if the value was null or empty and my friend helped me with this:
StrengthInfo = CASE WHEN ((SELECT COUNT(UnitsOrdered) FROM [Data_Sub_orders].[dbo].[Snappy_Orders_Sub] WHERE IdPatient = @PatientId and IdDrugService = 226)> 0)
THEN cast((S.UnitsOrdered) as varchar(50))
ELSE 'No Labs Available'
END
Solution 13 - Sql Server
You have to do both:
SELECT * FROM Table WHERE Text IS NULL or Text LIKE ''
Solution 14 - Sql Server
I know there are plenty answers with alternatives to this problem, but I just would like to put together what I found as the best solution by @Eric Z Beard & @Tim Cooper with @Enrique Garcia & @Uli Köhler.
If needed to deal with the fact that space-only could be the same as empty in your use-case scenario, because the query below will return 1, not 0.
SELECT datalength(' ')
Therefore, I would go for something like:
SELECT datalength(RTRIM(LTRIM(ISNULL([TextColumn], ''))))
Solution 15 - Sql Server
try this:
select * from mytable where convert(varchar, mycolumn) = ''
i hope help u!
Solution 16 - Sql Server
DECLARE @temp as nvarchar(20)
SET @temp = NULL
--SET @temp = ''
--SET @temp = 'Test'
SELECT IIF(ISNULL(@temp,'')='','[Empty]',@temp)
Solution 17 - Sql Server
> It will do two things: > > 1. Null check and string null check > 2. Replace empty value to default value eg NA.
SELECT coalesce(NULLIF(column_name,''),'NA') as 'desired_name') from table;