How to Alter all specific datatype to another datatype in whole table

Question

I have one table table_name with 50 decimal(18, 0) columns and I want to change it's datatype to decimal(18, 6)

I am trying

ALTER TABLE [table_name] ALTER COLUMN [column_name] [data_type]

But for this, I have to queries 50 times.

How I do it in a single Query

Answer 1

You can do it easily by executing a dynamic sql query.

Query

declare @sql as varchar(max);

select @sql = stuff((
        select 'alter table [your_table_name] 
        alter column [' + [column_name] + '] decimal(18, 6);'
        from information_schema.columns
        where [table_name] = 'your_table_name'
        and [data_type] = 'decimal'
        for xml path('')
    )
    , 1, 0, ''
);

exec(@sql);

Answer 2

You have to add all colunm seprated by comma ie

ALTER TABLE [table_name] ALTER COLUMN [column_name1] [data_type],[column_name2] [data_type],so on;