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
Related
I am trying to convert data type of one of my columns (the table was imported from Excel), and then it shows an error
Error converting data type nvarchar to float
Code:
ALTER TABLE [dbo].[games_activity_2020$]
ALTER COLUMN [Version] float
What can I do differently?
probably there might be any character values inserted in the table while importing from excel. You can check those values using the below query
SELECT version
from [dbo].[games_activity_2020$]
where TRY_CONVERT(float, version) IS NULL
you can update those values and try to ALTER the table again
I suggest you run
SELECT * FROM [dbo].[games_activity_2020$]
WHERE TRY_CAST([Version] as FLOAT) IS NULL
and fix up any problematic values
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.
Looking at a column that holds last 4 of someone's SSN and the column was originally created as an int datatype. Now SSN that begin with 0 get registered as 0 on the database.
How can I convert the column and it's information from an int into a string for future proof?
You should convert. CONVERT(VARCHAR(4), your_col)
If you specifically want zero-padded numbers, then the simplest solution is format():
select format(123, '0000')
If you want to fix the table, then do:
alter table t alter column ssn4 char(4); -- there are always four digits
Then update the value to get the leading zeros:
update t
ssn4 = format(convert(int, ssn4), '0000');
Or, if you just want downstream users to have the string, you can use a computed column:
alter table t
add ssn4_str as (format(ssn4, '0000'));
If you want to add leading zeros, use:
SELECT RIGHT('0000'+ISNULL(SSN,''),4)
First thing never store SSN or Zip Code as any numeric type.
Second you should fix the underlying table structure not rely on a conversion...but if you're in a jam this is an example of a case statement that will help you.
IF OBJECT_ID('tempdb..#t') IS NOT NULL
BEGIN
DROP TABLE #t
END
GO
CREATE TABLE #t(
LastFourSSN INT
)
INSERT INTO #t(LastFourSSN)
VALUES('0123'),('1234')
SELECT LastFourSSN --strips leading zero
FROM #t
SELECT -- adds leading zero to anything less than four charaters
CASE
WHEN LEN(LastFourSSN) < 4
THEN '0' + CAST(LastFourSSN AS VARCHAR(3))
ELSE CAST(LastFourSSN AS VARCHAR(4))
END LastFourSSN
FROM #t
If you are looking for converting values in the column for your purpose to use in application, you can use this following-
SELECT CAST(your_column AS VARCHAR(100))
--VARCHAR length based on your data
But if you are looking for change data type of your database column directly, you can try this-
ALTER TABLE TableName
ALTER COLUMN your_column VARCHAR(200) NULL
--NULL or NOT NULL based on the data already stored in database
I'm trying to filter some data - I have a column which looks like it is mainly smallint/int. Is there anyway I can run a where statement to say where not int or where not small int??
Microsoft SQL Server manager.
If you want a where clause that can tell you if the column contain information that can't be converted to int or smallint, you can use try_cast:
SELECT *
FROM <TableName>
WHERE TRY_CAST(<ColumnName> AS Int) IS NULL
You can change the int to smallint to get values that can't be converted to smallint but might be convertible to int.
Don't forget to replace <TableName> and <ColumnName> to the names of the relevant table and column.
The Try_Cast built in function will return null if the value in <ColumnName> is null or if it can't be converted to int (and since all smallint values can also be converted to int, it also can't be converted to smallint).
How do I change the data type float to nvarchar in order to remove the scientific notation and still keep precision? Consider the following:
CREATE TABLE ConversionDataType (ColumnData FLOAT);
INSERT INTO ConversionDataType VALUES (25566685456126);
INSERT INTO ConversionDataType VALUES (12345545546845);
INSERT INTO ConversionDataType VALUES (12345545545257);
When I do a simple read I get the following data, as expected:
select * from ConversionDataType
ColumnData
------------------------------------
25566685456126
12345545546845
12345545545257
Now when I try update the data type to an nvarchar, it gets stored in scientific notation which is something I don't want:
update ConversionDataType
set ColumnData = CAST(ColumnData AS NVARCHAR)
The result set is as follows:
25566700000000
12345500000000
12345500000000
It replaces some digits and adds zeros after the 6th index. How can I go about this? I had a look at the Convert function but that is only for converting date time data types.
Being valid what others said in comment, if you just want to convert float to varchar without scientific notation, you need to convert to numeric. You can try this:
SELECT CAST(CAST(CAST(25566685456126291 AS FLOAT) AS NUMERIC) AS NVARCHAR)
Output:
C1
------------------------------
25566685456126292
Whereas
SELECT CAST(CAST(25566685456126291 AS FLOAT) AS NVARCHAR) AS C1
gives:
C1
------------------------------
2.55667e+016
If you need to change datatype, I think you should add a new column, update it and (if you want) delete the old column and rename the new column at the end.
CREATE TABLE TEST1 (C1 FLOAT)
INSERT INTO TEST1 VALUES (25566685456126291);
ALTER TABLE TEST1 ADD C2 VARCHAR(18)
UPDATE TEST1 SET C2=CAST(CAST(C1 AS NUMERIC) AS VARCHAR)
SELECT * FROM TEST1
Output:
C1 C2
---------------------- ------------------
2.55666854561263E+16 25566685456126292
FLOAT was a very bad decision as this is not a precise data type. If you wanted to store the phone numbers as numbers, you'd have to go for DECIMAL instead.
But you'll have to use NVARCHAR instead. And this is the only reasonable design, as phone numbers can have leading zeros or start with a plus sign. So the first thing is to introduce an NVARCHAR column:
ALTER TABLE ConversionDataType ADD ColumnDataNew NVARCHAR(30);
The function to convert a number into a string in SQL Server is FORMAT. It lets you state the format you want to use for the conversion, which is integer in your case (a simple '0'):
update ConversionDataType set ColumnDataNew = format(ColumnData, '0');
At last remove the old column and then rename the new one with the same name. SQL Server lacks an ALTER TABLE syntax to rename a column, so we must call sp_RENAME instead (at least this is what I have read on the Internet; here is a link to the docs: https://msdn.microsoft.com/de-de/library/ms188351.aspx).
ALTER TABLE ConversionDataType DROP COLUMN ColumnData;
EXEC sp_RENAME 'ConversionDataType.ColumnDataNew', 'ColumnData', 'COLUMN';
Here you can see the results: http://rextester.com/GLLB27702
SELECT CONVERT(NVARCHAR(250), StudentID) FROM TableA
StudentID is your Float Column of database
or Simply use
SELECT CONVERT(NVARCHAR(250), yourFloatVariable)