where not dataype sql - sql

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).

Related

Conversion failed when converting the nvarchar value to data type int - Error Message

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

Nvarchar working with logical operator working?

Just need your help here.
I have a table T
A (nvarchar) B()
--------------------------
'abcd'
'xyzxcz'
B should output length of entries in A for which I did
UPDATE T
SET B = LEN(A) -- I know LEN function returns int
But when I checked out the datatype of B using sp_help T, it showed column B as nvarchar.
What's going on ?
select A
from T
where B > 100
also returned correct output?
Why is nvarchar working with logical operators ?
Please help.
Check https://learn.microsoft.com/en-us/sql/t-sql/data-types/data-type-conversion-database-engine?view=sql-server-2017 where it is said that data types are converted explicitly or implicitly when you move, compare or store a variable. In your case, you are comparing column B with 100, forcing sql server to implicitly convert it to integer type (check the picture about conversions on the same page). As a prove, try to alter a row putting some text in column B and, after repeating your select query B>100, sql server will throw a conversione error trying to obtain an integer out of your text.
It works because of implicit conversion between types.
Data type precedence
When an operator combines expressions of different data types, the data type with the lower precedence is first converted to the data type with the higher precedence. If the conversion isn't a supported implicit conversion, an error is returned.
Types precedence:
16. int
...
25. nvarchar (including nvarchar(max) )
In you example:
select A
from T
where B > 100
--nvarchar and int (B is implicitly casted to INT)
when adding a column to a table in ssms, not adding a datatype a "default" datatype is chosen. for me on 2017 developer it's nchar(10). if you want it to be int define the column with datatype of int. in tsql it'd be
create table T (
A nvarchar --for me the nvarchar without a size gives an nvarchar(2)
,B int
);
sp_help T
--to make a specific size, largest for nvarchar is 4000 or max...max is the replacement for ntext of old, as.
create table Tmax (
A nvarchar(max)
,B int
);
--understanding nvarchar and varchar for len() and datalength()
select
datalength(N'wibble') datalength_nvarchar -- nvarchar is unicode and uses 2 bytes per char, so 12
,datalength('wibble') datalength_varchar -- varchar uses 1 byte per so 6
,len(N'wibble') len_nvarchar -- count of chars, so 6
,len('wibble') len_varchar -- count of char so still 6
nvarchar(max) and varchar(max)
hope this helps, the question is a bit discombobulated

datatype for an iif statement

If in a SELECT statement there is the following line:
iif(fr.BoundID=0,'OutBound','InBound') as 'FlightBound'
Then when I perform a CREATE TABLE statement, should I include the actual datatype of the BoundID field which is a tinyint in the database table, or shall the datatype be varchar because I think (but not 100% sure looking at the existing code) that the previous person writing this code is saying display 'OutBound, InBound' if the ID is 0?
In your case it will be VARCHAR(8). You can always check metadata using sys.dm_exec_describe_first_result_set:
SELECT *
FROM sys.dm_exec_describe_first_result_set(
'SELECT iif(BoundID=0,''OutBound'',''InBound'') as ''FlightBound''
FROM #tab',NULL,0)
LiveDemo
What datatype to choose for new table TINYINT vs Textual representation is dependent on your business requirements. I would probably stay with TINYINT (search for lookup table named like BoundType or ask senior developer/architect).
The return type is the type in true_value and false_value with the highest precendence (reference, see return types)
Returns the data type with the highest precedence from the types in true_value and false_value. For more information, see Data Type Precedence (Transact-SQL).
Data type precendence here up to SQL Server 2016:
user-defined data types (highest)
sql_variant
xml
datetimeoffset
datetime2
datetime
smalldatetime
date
time
float
real
decimal
money
smallmoney
bigint
int
smallint
tinyint
bit
ntext
text
image
timestamp
uniqueidentifier
nvarchar (including nvarchar(max) )
nchar
varchar (including varchar(max) )
char
varbinary (including varbinary(max) )
binary (lowest)

Can't convert postgresql table column from type varchar to int

I have a database table of that I have used to store the data returned from a web spider. I have a column that contains ticket prices for different events all in the varchar type (as the scrapy spider has to scrape the data in unicode). I'm trying to return the min price of the column and since the min() function only works for data of type INT, I tried to convert the column to integers using a solution from this SO post:
ALTER TABLE vs_tickets ALTER COLUMN ticketprice TYPE integer USING (ticketprice::integer);
but I got the error: ERROR: invalid input syntax for integer:
I also tried: change_column :vs_tickets, :ticketprice, 'integer USING CAST(ticketprice AS integer)' but that didn't work either.
What is the proper way to convert the column to type INT?
Edit:
You have decimal places in the string, so a simple cast is not going to work. You can do a double conversion:
cast(cast(ticketprice as decimal(10, 2)) as int)
or:
(ticketprice::decimal(10, 2))::int
(The parens are not strictly necessary.)
EDIT:
Or, as Erwin points out, just use numeric:
(ticketprice::numeric)::int
Postgres is much smarter about numeric than most other databases . . . after all, it supports numbers that are egregiously large ;)
The final query is:
ALTER TABLE vs_tickets
ALTER COLUMN ticketprice TYPE integer USING (ticketprice::numeric::integer);
I'm going to bet on your column have wrong characters.
Also you may want use float or numeric because you will lose decimals if convert to integers.
You need create a function to check if a text is numeric like this isnumeric-with-postgresql
Then check each row like this
select ticketprice
from vs_tickets
where ISNUMERIC(ticketprice) = false;
As your comment you also should try
SELECT ticketprice::float
You will be best off adding an INT column, moving your data with a cast and then removing the old varchar column.
ALTER TABLE vs_tickets ADD COLUMN ticketprice_int TYPE int;
GO
update vs_tickets SET ticketprice_int = cast(ticketprice as int);
// if you fail to cast the varchar to int you can use Gordon's method
// update vs_tickets SET ticketprice_int = cast(cast(ticketprice as decimal(10, 2)) as int);
GO
ALTER TABLE vs_tickets DROP COLUMN ticketprice;
GO
ALTER TABLE vs_tickets RENAME COLUMN ticketprice_int to ticketprice;
GO
With this at minimum you will be able to tell if and where a cast/convert fails and be able to check and recheck at each step before you can't turn back.

Why am i getting this error when am creating a table?

I am creating a new table, with various data type, one them in binary(n). When I execute the statement, I end up with the following
Implicit conversion from data type varchar to binary is not allowed, use CONVERT function.
My question: why do I get this error, when there is no data to convert, I am just creating a table?
Create Table EMP.DETAILS
(
ID INT NOT NULL,
TYPE INT,
Created datetime2,
Key_No varchar(5),
Batch_IN INT,
UN_ID BINARY(1) not null default '',
Source INT,
SITE CHAR(1)
)
When I execute the above statement, I get the error mentioned above, But it directs me to the CREATE TABLE line of the code.
The error says "Implicit conversion from data type varchar to binary is not allowed". You are trying to assign a default varchar character to a binary here:
UN_ID BINARY(1) not null default ''
If you absolutely need a default value for a binary column, you can set it directly as something like 0x00:
UN_ID BINARY(1) not null default 0x00
That will basically set your default to 0. You can also set it to an integer value:
UN_ID BINARY(1) not null default 0
And finally, if you absolutely need to to be an empty string, you can find the binary representation of '' with the following SELECT:
SELECT CONVERT(binary, '')
I'm pretty sure it's just 0, though.
Depending on what that column is being used for, though, it might be better suited as a tinyint, char(1), or something similar, rather than a binary(1).