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.
Related
My Query
Select * from MyTable
The table consists 300k rows.
It runs for 200k+ rows and this error pops up.
How to handle this to get the full data?
Does MyTable have any computed columns?
Table consists of a computed column with the name IsExceeds which is given below for your reference.
This is the computed column formula:
(CONVERT([int],[Pro_PCT])-CONVERT([int],replace([Max_Off],'%','')))
Field Definitions:
[Pro_PCT] [nvarchar](50) NULL,
[Max_Off] [nvarchar](50) NULL,
[IsExceeds] AS (CONVERT([int],[Pro_PCT])-CONVERT([int],replace([Max_Off],'%','')))
Kindly convert in float then convert into int.
declare #n nvarchar(20)
set #n='11.11'
if (isnumeric(#n)=0)
SELECT 0
else
SELECT CAST(CONVERT(float, #n) as int) AS n
Why are you storing amounts as strings? That is the fundamental problem.
So, I would suggest fixing your data. Something like this:
update mytable
set max_off = replace(max_off, '%');
alter table mytable alter pro_pct numeric(10, 4);
alter table mytable alter max_off numeric(10, 4);
(Without sample data or an example of the data I am just guessing on a reasonable type.)
Then, you can define IsExceeds as:
(Pro_PCT - Max_Off)
Voila! No problems.
Based on the formula - either Pro_PCT or Max_Off contains the value 11.11 (well, with an extra % for Max_Off. Perhaps they also contain other values that can't be converted to int.
Here's what you can do to find all the rows that will cause this problem:
Select *
from MyTable
where try_cast(Pro_PCT as int) is null
or try_cast(replace([Max_Off],'%','') as int) is null
After you've found them, you can either fix the values or change the calculation of the computed column to use try_cast or try_convert instead of convert.
Check the bad data with
select * from MyTable where isnumeric( Max_Off ) = 0
(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
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;
First, thanks for all your help! You really make a difference, and I GREATLY appreciate it.
So I have a Varchar column and it holds a 16 digit number, example: 1000550152872026
select *
FROM Orders
where isnumeric([ord_no]) = 0
returns: 0 rows
select cast([ord_no] as bigint)
FROM Progression_PreCall_Orders o
order by [ord_no]
returns: Error converting data type varchar to bigint.
How do I get this 16 digit number into a math datatype so I can add and subtract another column from it?
UPDATE: Found scientific notation stored as varchar ex: 1.00054E+15
How do I convert that back into a number then?
DECIMAL datatype seems to work fine:
DECLARE #myVarchar AS VARCHAR(32)
SET #myVarchar = '1000550152872026'
DECLARE #myDecimal AS DECIMAL(38,0)
SET #myDecimal = CAST(#myVarchar AS DECIMAL(38,0))
SELECT #myDecimal + 1
Also, here's a quick example where IsNumeric returns 1 but converting to DECIMAL fails:
DECLARE #myVarchar AS VARCHAR(32)
SET #myVarchar = '1000550152872026E10'
SELECT ISNUMERIC(#myVarchar)
DECLARE #myDecimal AS DECIMAL(38,0)
SET #myDecimal = CAST(#myVarchar AS DECIMAL(38,0)) --This statement will fail
EDIT
You could try to CONVERT to float if you're dealing with values written in scientific notation:
DECLARE #Orders AS TABLE(OrderNum NVARCHAR(64), [Date] DATETIME)
INSERT INTO #Orders VALUES('100055015287202', GETDATE())
INSERT INTO #Orders VALUES('100055015287203', GETDATE())
INSERT INTO #Orders VALUES('1.00055015287E+15', GETDATE()) --sci notation
SELECT
CONVERT(FLOAT, OrderNum, 2) +
CAST(REPLACE(CONVERT(VARCHAR(10), GETDATE(), 120), '-', '') AS FLOAT)
FROM #Orders
WITH validOrds AS
(
SELECT ord_no
FROM Orders
WHERE ord_no NOT LIKE '%[^0-9]%'
)
SELECT cast(validOrds.ord_no as bigint) as ord_no
FROM validOrds
LEFT JOIN Orders ords
ON ords.ord_no = validOrds.ord_no
WHERE ords.ord_no is null
Take a look at this link for an explanation of why isnumeric isn't functioning the way you are assuming it would: http://www.sqlservercentral.com/articles/IsNumeric/71512/
Take a look at this link for an SO post where a user has a similar problem as you:
Error converting data type varchar
hence, you should always use the correct datatype for each column unless you have a very specific reason to do so otherwise... Even then, you'll need to be extra careful when saving values to the column to ensure that they are indeed valid values
I'm bumping into somenull fields in a SQL2005 db.
Some report Null and others have values like 1.00 or 713.00.
I'd like a bullet proof way to convert the 'Null's to 0 and the '1.00' and '713.00' values into Money types.
CREATE TABLE dbo.Test_Text_Convert
(
my_string TEXT NULL
)
GO
INSERT INTO dbo.Test_Text_Convert VALUES (NULL)
INSERT INTO dbo.Test_Text_Convert VALUES ('7.10')
INSERT INTO dbo.Test_Text_Convert VALUES ('xxx')
INSERT INTO dbo.Test_Text_Convert VALUES ('$20.20')
INSERT INTO dbo.Test_Text_Convert VALUES ('20.2020')
GO
SELECT
CASE
WHEN ISNUMERIC(CAST(my_string AS VARCHAR(MAX))) = 1
THEN CAST(ISNULL(CAST(my_string AS VARCHAR(MAX)), '0') AS MONEY)
ELSE 0
END
FROM
dbo.Test_Text_Convert
GO
I've set invalid strings to be 0, but you could easily change that behavior.
You can convert from null via the coalesce function:
coalesce(a, b) //returns b if a is null, a otherwise
To cast from text to money and handle nulls, try this:
CAST(COALESCE(column, '0') AS MONEY)
See COALESCE and CAST for details.
An alternative when things are more complex is CASE..WHEN.
I'm not sure what the performance will be like, but 2005 introduced the varchar(MAX) and nvarchar(MAX) data types (among others like varbinary(MAX). These are true varchars and nvarchars, and can be used in any place where they could (like Convert), but also have the capacity of Text and Image fields. In fact, the Text and Image types are actually deprecated, so going forward it's recommended that you use the new types.
That being said, you could just use this:
convert(Money, coalesce(text_column_name, 0))