更改表列语法错误

Question

I needed to create a table with dynamic columns, so I created a cursor that loops through the records of a table and will create the necessary columns, however, is giving me this error:

Incorrect syntax near 'INT'.

Example code:

SELECT @sql = 'ALTER TABLE #temp3 ADD ' + @nome + ' INT'
EXEC (@sql);

I have also tried this:

EXEC ('ALTER TABLE #temp3 ADD ' + @nome + ' INT')

But still the same error

Any suggestions?

Edit: Examples of values ​​that can receive @nome

• Very Bad
• Bad
• Good
• Very Good

Answer 1

You've indicated that @nome may contain, for instance, Very Bad. If that is so, it contains a space - you need to delimit the name so that SQL Server knows that the space is part of the name:

SELECT @sql = 'ALTER TABLE #temp3 ADD [' + @nome + '] INT'
EXEC (@sql);

or more properly, use QUOTENAME

SELECT @sql = 'ALTER TABLE #temp3 ADD ' + QUOTENAME(@nome) + ' INT'
EXEC (@sql);

Otherwise, SQL Server is trying to add a column called Very with a datatype of Bad , and it doesn't even know how to interpret int after that.

Answer 2

thanks to @Damien that encourage me to investigate:

if object_id(N'#tempg') is not null
    drop table #tempg

select 1 as i into #tempg

select * from #tempg

alter table #tempg add j int

exec sp_executesql N'alter table #tempg add k int'

select * from #tempg

note that

exec 'alter table #tempg add l int'

fails with

Msg 102, Niveau 15, État 1, Ligne 1
Syntaxe incorrecte vers 'alter table #tempg add l int'.

============================================= Edition

exec ('alter table #tempg add l int')

runs