(Beginner at sql)
I've been getting the error
'Error converting data type nvarchar to float.'
Which is because I was trying to round an nvarchar(10) column with both characters and integers, and obviously it can't round the characters. (I can't make two separate columns with different data types as they both need to be in this column)
I'm looking for a way to round the numbers in the nvarchar column whilst also returning the characters
I've being trying CAST/Converts nothing seems to work
I've also tried
CASE WHEN ISNUMERIC(Tbl1.Column1) = 1
THEN cast(Round(Tbl1.Column1, 0) AS float)
ELSE Tbl1.Column1 END AS 'Column1'
in the select statement
I cant figure out what else will solve this!
Sample Data in this column would be
8.1
2
9.0
9.6
A
-
5.3
D
E
5.1
-
I would go for try_convert() instead of isnumeric():
COALESCE(CONVERT(VARCHAR(255), TRY_CONVERT(DECIMAL(10, 0), Tbl1.Column1)),Tbl1.Column1) as Column1
A conversion problem arises with your approach because a case expression returns a single value. One of the branches is numeric, so the return type is numeric -- and the conversion in the else fails.
You can fix your version by converting the then clause to a string after converting to a float.
since you hold both types in this column, you need to cast your rounded value back to varchar
declare #Tbl1 table (Column1 varchar(10))
insert into #Tbl1 (Column1) values ('8.1'), ('2'), ('9.0'),
('9.6'), ('A'), ('5.3'),
('D'), ('E'), ('5.1'), ('-')
select case when TRY_CONVERT(float, Column1) IS NULL then Column1
else cast(cast(Round(Column1, 0) as float) as varchar(10))
end AS 'Column1'
from #Tbl1
outcome is
Column1
-------
8
2
9
10
A
5
D
E
5
-
In case you get the error TRY_CONVERTis not a build-in function then you have your database compatibility level is less that SQL 2012.
You can correct that using this command
ALTER DATABASE your_database SET COMPATIBILITY_LEVEL = 120;
Also note that after this statement the answer of Gordon is working now, and I agree that is a better answer then mine
Related
I've come across an issue (that I've partially solved) but can't seem to find a reason behind the failing in the first place.
I have a field in a table which holds a combination of alpha and numerical values. The field is a char(20) data type (which is wrong, but unchangeable) and holds either a NULL value, 'Unknown' or the "numbers" 0, 50, 100. The char field pads the values with trailing white space. This is a known and we can't do a thing about it.
To remove the Unknown values, we have a series of coalesce statements in place, and these two return the error message as per the title.
,coalesce(DHMCC.[HESA Module Total Proportion Taught], 'Missing')
,cast(isnull(DHMCC.[HESA Module Total Proportion Taught] ,'Missing') as varchar(10))
The query I have is why am I getting this error when I'm not converting a data type of varchar to float (or am I?)
Does anyone have an idea as to where to look next to try to fix this error?
The STR() function accepts a float datatype as the first argument, therefore SQL Server is implicitly converting whatever you pass to this function, which in your case is the CHAR(20) column. Since unknown can't be converted to a float, you get the error.
If you run the following with the actual execution plan enabled:
DECLARE #T TABLE (Col CHAR(20));
INSERT #T VALUES (NULL);
SELECT Result = ISNULL(STR(Col, 25, 0), 'Missing')
FROM #T
Then checkthe execution plan XML you will see the implicit conversion:
<ScalarOperator ScalarString="isnull(str(CONVERT_IMPLICIT(float(53),[Col],0),(25),(0)),'Missing')">
The simplest solution is probably to use a case expression and not bother with any conversion at all (only if you know you will only have the 5 values you listed:
DECLARE #T TABLE (Col CHAR(20));
INSERT #T VALUES (NULL), ('0'), ('50'), ('100');--, ('Unknown');
SELECT Result = CASE WHEN Col IS NULL OR Col = 'Unknown' THEN 'Missing' ELSE Col END
FROM #T;
Result
---------
Missing
0
50
100
Missing
If you really want the STR() function, you can make the conversion explicit, but use TRY_CONVERT() so that anything that is not a float simply returns NULL:
DECLARE #T TABLE (Col CHAR(20));
INSERT #T VALUES (NULL), ('0'), ('50'), ('100');--, ('Unknown');
SELECT Result = ISNULL(STR(TRY_CONVERT(FLOAT, Col), 25, 0), 'Missing')
FROM #T
Result
------------
Missing
0
50
100
Missing
Although, since you the numbers you have stated are integers, I would be inclined to convert them to integers rather than floats:
DECLARE #T TABLE (Col CHAR(20));
INSERT #T VALUES (NULL), ('0'), ('50'), ('100'), ('Unknown');
SELECT Result = ISNULL(CONVERT(VARCHAR(10), TRY_CONVERT(INT, Col)), 'Missing')
FROM #T;
Result
---------
Missing
0
50
100
Missing
Thanks to #GarethD
I've only just come across TRY_CONVERT and this seems like the better option, so thanks him for that pointer, also trying with TRY_CAST as well.
The data really should be held in a varchar field, it's referential and not for calculation, and this seems to work equally as well,
-- Declare #varText as varchar(16) = '10 '
-- Declare #varText as char(16) = 'Unknown'
-- Declare #varText as char(16) = ''
SELECT
ISNULL(NULLIF(TRY_CAST(LTRIM(RTRIM(#varText)) as varchar(16)), ''), 'Missing') AS HESA
I've created this test scenario which works ok.
I have a conundrum....
There is a table with one NVARCHAR(50) Float column that has many rows with many numbers of various decimal lengths:
'3304.063'
'3304.0625'
'39.53'
'39.2'
I need to write a query to find only numbers with decimal places >= 4
First the query I wrote was:
SELECT
Column
FROM Tablename
WHERE Column LIKE '%.[0-9][0-9]%'
The above code finds all numbers with decimal places >= 2:
'3304.063'
'3304.0625'
'39.53'
Perfect! Now, I just need to increase the [0-9] by 2...
SELECT
Column
FROM Tablename
WHERE Column LIKE '%.[0-9][0-9][0-9][0-9]%'
this returned nothing! What?
Does anyone have an explanation as to what went wrong as well and/or a possible solution? I'm kind of stumped and my hunch is that it is some sort of 'LIKE' limitation..
Any help would be appreciated!
Thanks.
After your edit, you stated you are using FLOAT which is an approximate value stored as 4 or 8 bytes, or 7 or 15 digits of precision. The documents explicitly state that not all values in the data type range can be represented exactly. It also states you can use the STR() function when converting it which you'll need to get your formatting right. Here is how:
declare #table table (columnName float)
insert into #table
values
('3304.063'),
('3304.0625'),
('39.53'),
('39.2')
--see the conversion
select * , str(columnName,20,4)
from #table
--now use it in a where clause.
--Return all values where the last digit isn't 0 from STR() the conversion
select *
from #table
where right(str(columnName,20,4),1) != 0
OLD ANSWER
Your LIKE statement would do it, and here is another way just to show they both work.
declare #table table (columnName varchar(64))
insert into #table
values
('3304.063'),
('3304.0625'),
('39.53'),
('39.2')
select *
from #table
where len(right(columnName,len(columnName) - charindex('.',columnName))) >= 4
select *
from #table
where columnName like '%.[0-9][0-9][0-9][0-9]%'
One thing that could be causing this is a space in the number somewhere... since you said the column type was VARCHAR this is a possibility, and could be avoided by storing the value as DECIMAL
declare #table table (columnName varchar(64))
insert into #table
values
('3304.063'),
('3304. 0625'), --notice the space here
('39.53'),
('39.2')
--this would return nothing
select *
from #table
where columnName like '%.[0-9][0-9][0-9][0-9]%'
How to find out if this is the case?
select *
from #table
where columnName like '% %'
Or, anything but numbers and decimals:
select *
from #table
where columnName like '%[^.0-9]%'
The following is working fine for me:
declare #tab table (val varchar(50))
insert into #tab
select '3304.063'
union select '3304.0625'
union select '39.53'
union select '39.2'
select * from #tab
where val like '%.[0-9][0-9][0-9][0-9]%'
Assuming your table only has numerical data, you can cast them to decimal and then compare:
SELECT COLUMN
FROM tablename
WHERE CAST(COLUMN AS DECIMAL(19,4)) <> CAST(COLUMN AS DECIMAL(19,3))
You'd want to test the performance of this against using the character data type solutions that others have already suggested.
You can use REVERSE:
declare #vals table ([Val] nvarchar(50))
insert into #vals values ('3304.063'), ('3304.0625'), ('39.53'), ('39.2')
select [Val]
from #Vals
where charindex('.',reverse([Val]))>4
I have a table with a column of varchar type. The column contains 568710 records of numeric (I mean the ISNUMERIC() returns 1) and 91 records of null values (i.e., the ISNUMERIC() returns 0). Now, I need to convert the column to FLOAT without losing the null records or replacing them with any other value. Is it possible in SQL?
When I use CONVERT(FLOAT, [Value]) conversion, I get the following error:
Msg 8114, Level 16, State 5, Line 48
Error converting data type varchar to float.
I read that the null can be converted to any type. So it should be possible.
You can use this
SELECT CONVERT(float, CASE WHEN ISNUMERIC(columnName) = 1 THEN columnName ELSE NULL END) FROM TableABC
Try :::
ALTER TABLE tablename
ADD NewFloatColumn FLOAT
UPDATE TableName
SET NewFloatColumn =
CASE WHEN ISNUMERIC(VarcharColumn) =1 THEN CAST (VarcharColumn AS float)
WHEN UPPER(VarcharColumn) = 'NULL' THEN null
END
Select (CASE WHEN ISNUMERIC(c) = 1
THEN (CASE WHEN c LIKE '%.%' THEN c ELSE c + '.00' END)
ELSE '0.00'
END)from table_name
I just spent some time scratching my head at the same problem. I was able to resolve this by converting first to int, then to float. Testing shows no data loss as my float column did not contain decimal, it simply had to match the dtype of another column for a later UNION operation.
This was completed on SQL Server 2016.
ALTER TABLE table1
ALTER COLUMN column1 int;
ALTER TABLE table1
ALTER COLUMN column1 float;
I have two table. First table(Table1) use to get the records and second table(Table2) used to insert first table record into it. But I am little bit confused after getting result.
In table 1 and table 2 column "Amount" have same data type i.e nvarchar(max)
Table1
Id Amount
1 Null
2 -89437.43
2 -533.43
3 22403.88
If I run this query
Insert into Table2(Amount)
Select Amount from Table1
Then get result like this, I don't know why values are automatically rounded off
Table2
Id Amount
1 Null
2 -89437.4
2 -533.43
3 22403.9
SQL Server will round float values when converting back and to from string types.
And then you have the fun bits of empty string being 0, as well other strange effects
SELECT CAST(CAST('' AS float) AS nvarchar(MAX))
SELECT CAST(CAST('0.E0' AS float) AS nvarchar(MAX))
Use decimal.
If you need to store "blank" (how does this differ from NULL?) use a separate bit column to allow that extra value
Here is good explanation about your question.
Eigher you explicitly give float or decimal or numeric(xx,x) (x means numeric value)
Then it will convert as the data, other wise it round off the last value.
Insert into Table2(Amount)
Select cast(Amount as numeric(18,2) --or , cast (Amount as float)
from Table1
Check this link:-
TSQL Round up decimal number
In my case I was doing the conversion to the correct data type but had decimal(18,0) for the column in the table. So make sure the decimal places are represented properly for the column decimal(18,2).
Perhaps it's your query tool that's truncating to 8 characters.
Check the actual fields lengths to see if the problem is really in the database:
SELECT LEN(Amount)
FROM Table2
WHERE Amount LIKE '%-89437.%'
Unreproducible. Running this script on SQL Server 2012:
DECLARE #T1 TABLE ([Amount] nvarchar(max) NULL);
DECLARE #T2 TABLE ([Amount] nvarchar(max) NULL);
INSERT INTO #T1 ([Amount])
VALUES (NULL),('-89437.43'),('-533.43'),('22403.88');
Insert into #T2(Amount)
Select Amount from #T1;
SELECT * FROM #T2;
Produces this result:
Amount
NULL
-89437.43
-533.43
22403.88
The problem you describe does not exist.
This will show you the problem:
DECLARE #T1 TABLE ([Amount123456789] money NULL);
DECLARE #T2 TABLE ([Amount123456789] nvarchar(max) NULL);
INSERT INTO #T1 ([Amount123456789])
VALUES (NULL),('-89437.43123'),('-533.43456'),('22403.88789'),(22403.88789);
Insert into #T2(Amount123456789)
Select Amount123456789 from #T1;
SELECT * FROM #T1;
SELECT * FROM #T2;
I have a query that I'm attempting to check the scode column for a range of code numbers. The problem is the scode column includes some nvarchar characters, and errors when it finds them.
How can I run the following query, without returning errors.
SELECT dtExpires, dtFirst
FROM Customers
WHERE (scode BETWEEN 10 AND 100) OR
(scode BETWEEN 500 AND 600)
Error I'm receiving:
Conversion failed when converting the nvarchar value to a data type int
If you can't FIX THE DATA TYPE which is really what you SHOULD be doing...
The only reliable way to short-circuit is to stuff filtered results into a #temp table. Otherwise you have no control over order of evaluation. Even if you use a subquery or CTE to filter rows where ISNUMERIC() = 1 "first", SQL Server might evaluate the BETWEEN conditional first, and still fail with the same error. This may not always happen, but this is the only way to guarantee you avoid it:
SELECT dtExpires, dtFirst, scode
INTO #t
FROM dbo.Customers
WHERE scode NOT LIKE '%[^0-9]%'; -- this assumes no decimals allowed
SELECT dtExpires, dtFirst
FROM #t
WHERE (scode BETWEEN 10 AND 100)
OR (scode BETWEEN 500 AND 600);
DROP TABLE #t;
Your ultimate problem here is that you are storing these number values as nvarchar. This is problematic for several reasons first of is speed. There are tons of great documents and answers out there showing this is the case many of them on this very Website.
Integer values are smaller than character strings you can fit much more per page than you can with nvarchar and mathematics are more easily done on integers. Try a little experiment go to SQLFiddle and enter your table and give it some values and run your query. Then try changing that column to an integer value and running the same query not only will it run faster but your current SELECT statement will run properly. If you ever need to join on this information and integer will me much faster as well.
I'm not entirely sure as to weather or not you have the power to do this or not but it will certainly fix your problem and improve your database performance as well.
Maybe use something like
SELECT dtExpires, dtFirst
FROM Customers
WHERE ( cast(fnRemoveNonNumericCharacters(scode) as int) BETWEEN 10 AND 100) OR
(cast(fnRemoveNonNumericCharacters(scode) as int)BETWEEN 500 AND 600)
where the function is :
CREATE Function [fnRemoveNonNumericCharacters](#strText VARCHAR(1000))
RETURNS VARCHAR(1000)
AS
BEGIN
WHILE PATINDEX('%[^0-9]%', #strText) > 0
BEGIN
SET #strText = STUFF(#strText, PATINDEX('%[^0-9]%', #strText), 1, '')
END
RETURN #strText
END
or if you want to exclude those entries where scode is not numeric make also a bool returning function that will tell you if it has non numeric chars and put it in the where clause.
also a way to solve this might be: (inspired a lil bit by Aron
SELECT dtExpires, dtFirst
FROM Customers
WHERE (( case when scode LIKE '%[^0-9]%' then 0 else scode end BETWEEN 10 AND 100) OR
(case when scode LIKE '%[^0-9]%' then 0 else scode end BETWEEN 500 AND 600))
and scode not like '%[^0-9]%'