Convert int in string to integers in T-SQL - sql

I need to convert string to integers, but I'm getting a type error.
declare #stringinteger nvarchar(255) null;
set #stringinteger='1,2,3,4'
select *
from user
where id in (#stringinteger)
The error I get:
Conversion failed when converting the nvarchar value '1,2,3,4' to data type int

You have two methods to handle this, dynamic SQL and splitting the string.
For the latter, you can use string_split() (introduced in SQL Server 2016) or a similar function (they are all over the web, google "string split sql server"):
select *
from user
where id in (select cast(value as int) from string_split(#stringinteger, ',')) ;
The dynamic SQL looks like:
declare #stringinteger nvarchar(255) null;
set #stringinteger = '1,2,3,4';
declare #sql nvarchar(max);
set 'select *
from user
where id in (#stringinteger)';
set #sql = replace(#sql, '#stringinteger', #stringinteger);
exec sp_executesql #sql;
Note that in SQL Server, you should always provide a length for character types. If you leave it out, then the default varies by context -- and your code may not do what you expect.

Related

IN with Varchar is not working sql server

Below code is throwing error
declare #test varchar(100)='20,201,202,288'
SELECT * from Business where Businessid in (#test)
i.e.
Conversion failed when converting the varchar value '20,201,202,288' to data type int.
how can i make it working, i'm not getting, might be my mind is not able think any more..
You can use string_split():
select *
from Business
where Businessid in (select value from string_split(#test, ','));
You are confusing a string with a list of values in an in list. They are not the same thing.
We can use string_split in SQL Server 2016 and later versions only so I choose dynamic query for any version with more flexibility
DECLARE #test VARCHAR(100) = '20,201,202,288', #sql VARCHAR(250)
SET #sql = '
SELECT *
FROM Business
WHERE Businessid IN (' + #test + ')'
EXEC(#sql)

How do i convert variable name to string name?

Assume I have the following SQL snippet in SQL Server 2012:
DECLARE #fname varchar(20), #strVarName varchar(50)
SET #fname = 'cronus'
SET #strVarName = COVERT_VARIABLE_TO_STRING_NAME ( #fname)
--this should return '#fname'. this is not a value conversion this is converting a variable name to a string name
SELECT #strVarName
How do I do this?
SQL Server does not support reflection. You may be able to retrieve column or table names from its catalog views but with variables you're out of luck. Maybe you'll find another way to solve this issue with dynamic SQL.
Use dynamic sql query
DECLARE #fname varchar(20), #sql varchar(MAX)
SET #fname = 'cronus'
SET #sql = 'SELECT ' + #fname
EXEC (#sql)
There are following Character data types used to store character strings:
char,
varchar,
nvarchar,
text,
If u already used variable as String then why need to convert as a string
DECLARE #fname varchar(20), #strVarName varchar(50)
SET #fname = 'cronus'
SET #strVarName = #fname
SELECT #strVarName
if needed use CAST and CONVERT function
This is such a bizarre question, sounds like something I'd try to do.
Hmm, SQL is not supposed to do this but I guess, it doesn't mean you can't make it.
I think you would effectively have to write your own process to pull this off, something along the lines of:
Create dbo.sProcInserts stored procedure to insert values into a table:
Takes VariableName, Value and possibly table name to insert into as parameters
Create dbo.sProcExec stored procedure to execute stored procedure:
Before execute, read stored procedure into a variable
Find all variables that are SET (i.e. they have a SET #Var = OR SELECT #Var =)
After each variable set, add to your string a line that calls dbo.sProcInserts with the name of the variable and a select #Variable
Execute your newly written stored procedure
That way you don't have to actually make any modifications to your sProcs and it should catch the flow of variables and their changes through your procedure
However the requirement itself is a bit strange for me, but here is a way that could be a good start point for you:
declare #var1 int
Set #var1= 1
--some code here
declare #var2 nvarchar(max)
set #var2 = 10
--some other code here
declare #var3 bit
print ##VERSION
print 'this is fake #value inside a string'
--$ This is a Hint to help me find the Query that should parsed
declare #sql varbinary(max)
select #sql=sql_handle
from sys.sysprocesses
where spid=56
declare #q nvarchar(max)
select #q= substring(text,1,charindex('$',text)-3) from sys.dm_exec_sql_text(#sql)
Select distinct rtrim(ltrim(substring(Name,1,charindex(' ',Name)))) as Name from(
Select substring(replace(Name,'=',' '),8, Len(Name)) as Name from dbo.SplitString(#q,'declare ')
) as K
where Name like '#[^#]%'
By running the above query you will get the variables name.
Output:
#var1
#var2
#var3
You can find the source code for SplitString function Here
Note: If you are using SQL Server 2016 and your database's compatibility level is equal or greater than 130, you can also use SPLIT_STRING introduced by Microsoft it self. Learn more Here

Conversion failed when converting the nvarchar value ... to data type int

I created the procedure listed below:
CREATE procedure getdata
(
#ID int,
#frm varchar(250),
#to varchar(250)
)
AS
BEGIN
DECLARE #SQL nvarchar(500)
set #SQL = 'select'
set #SQL = #SQL + ' EmpName, Address, Salary from Emp_Tb where 1=1 '
IF (#ID <> '' and #ID is not null)
Begin
SET #sql=#sql+' AND Emp_Id_Pk=' +#ID
End
END
print #sql
--execute (#sql)
I try to execute it using:
**execute getdata 3,'','';**
But I'm getting the following error:
Conversion failed when converting the nvarchar value 'select EmpName,
Address, Salary from Emp_Tb where 1=1 AND Emp_Id_Pk=' to data type int
Please help.
You are trying to concatenate a string and an integer.
You need to cast #ID as a string.
try:
SET #sql=#sql+' AND Emp_Id_Pk=' + CAST(#ID AS NVARCHAR(10))
Try Using
CONVERT(nvarchar(10),#ID)
This is similar to cast but is less expensive(in terms of time consumed)
I was using a KEY word for one of my columns and I solved it with brackets []
I use the latest version of SSMS or sql server management studio. I have a SQL script (in query editor) which has about 100 lines of code. This is error I got in the query:
Msg 245, Level 16, State 1, Line 2
Conversion failed when converting the nvarchar value 'abcd' to data type int.
Solution - I had seen this kind of error before when I forgot to enclose a number (in varchar column) in single quotes.
As an aside, the error message is misleading. The actual error on line number 70 in the query editor and not line 2 as the error says!
don't use string concatenation to produce sql, you can use sp_executesql system stored prcedure to execute sql statement with parameters
create procedure getdata #ID int, #frm varchar(250), #to varchar(250) as
begin
declare #sql nvarchar(max), #paramDefs nvarchar(max);
set nocount on;
set #sql = N'select EmpName, Address, Salary from Emp_Tb where #id is null or Emp_Id_Pk = #id';
set #paramDefs = N'#id int';
execute sp_executesql #sql, #paramDefs, #id = #ID;
end
see sp_executesql
I got this error when I used a where clause which looked at a nvarchar field but didn't use single quotes.
My invalid SQL query looked like this:
SELECT * FROM RandomTable WHERE Id IN (SELECT Id FROM RandomTable WHERE [Number] = 13028533)
This didn't work since the Number column had the data type nvarchar. It wasn't an int as I first thought.
I changed it to:
SELECT * FROM RandomTable WHERE Id IN (SELECT Id FROM RandomTable WHERE [Number] = '13028533')
And it worked.
You got this Error because you tried to convert column DataType from String to int which is
leagal if and only if
you dont have row in that table with string content inside that column
so just make sure your previously inserted Rows is compatible with the new changes
I have faced to the same problem, i deleted the constraint for the column in question and it worked for me. You can check the folder Constraints.
Capture :
You must use CONCAT and not the +
SET #sql = CONCAT(#sql,' AND Emp_Id_Pk=' ,#ID )

How to set a variable to the result of a sql query with a variable as a table name in SQL 2005

I'm currently having trouble writing a stored procedure and setting the value of a variable of type int to the results of a select statement with a variable as the tablename. I've looked at old threads and tried multiple methods, but no luck. If I'm not getting an error regarding the tablename, I end up getting an error with a variable conversion issue. I've been working on this for too long and any help would be appreciated. Below is a portion of my code. Thanks
DECLARE #BATCHNUMBER VARCHAR --value set in earlier code
DECLARE #ETABLE VARCHAR(50); --the table name
DECLARE #FIRSTDOCID INT;
SET #ETABLE = 'tablename_' + #BATCHNUMBER; --CREATE FIRST TABLE NAME
SELECT #FIRSTDOCID = MIN(D0CID) FROM #ETABLE
The error I get is: Must declare the table variable "#ETABLE"
You are trying to select from a VARCHAR, not a table. The only way to make this work is by using Dynamic SQL.
DECLARE #SQL NVARCHAR(250);
SET #SQL = 'SELECT #OUTPUT = MIN(D0CID) FROM ' + QuoteName(#ETABLE);
EXEC sp_executeSql #SQL, N'#output INT OUTPUT', #FIRSTDOCID OUTPUT;
SELECT #FIRSTDOCID;
However, I would not suggest using Dynamic SQL as this often leads to SQL injection.
You'll probably have to do something like use exec if you're dynamically building the query:
SET #QUERY = "SELECT" + ...etc.
exec(#QUERY)
Since ETABLE is a varchar, and not, as expected, a 'table variable'.

Generic SQL to get max value given table and column names as varchar

it is very easy to use the following SQL to get value for a specific primary key: ID from a specific table: myTale:
DECLARE #v_maxID bigint;
SELECT #v_maxID = MAX(ID) FROM myTable;
What I need is a generic SQL codes to get the max value for a key from a table, where both key and table are specified as varchar(max) types as parameters:
DECLARE #v_maxID bigint;
-- SELECT #v_maxID = MAX(#p_ID) FROM #p_Table;
I comment out the SELECT since it is not working. I tried to build a SQL string and I can EXEC it, but I cannot get the max value back to my local variable(#v_maxID). Any suggestions?
DECLARE #max bigint, #sql nvarchar(max)
SET #sql = N'SELECT #max = MAX(' + #p_ID + ') FROM ' + #p_Table
EXEC sp_executesql
#query = #sql,
#params = N'#max bigint OUTPUT',
#max = #max OUTPUT
PRINT #max
Users are choosers, but I consider this an ugly idea (for being overgeneralized). And unoptimizable. Just write the SQL.
Correct me if I'm wrong, but don't you just want:
SELECT MAX(ID) FROM mytable
Just build the query at the app level, thus the query running would be just like the one above. Doing in on sql will certainly open you for sql injection, since you have to use exec(). Also in either case, be careful with user input.
As BC states, you have to use sp_executesql with an OUTPUT parameter.
How to specify output parameters when you use the sp_executesql stored procedure in SQL Server