Loop through columns in Impala SQL Editor table

I am trying to create a sql script that counts the number of unique values for each column in a table. I do not want to hardcode any column names. The below sql statement works in a SQL server management studio, but not in my instance of Hue Impala. I’m pretty new to Impala as well so I’m not quite sure why the below sql isn’t working. Running the sql below returns the following error: “ParseException: Syntax error in line 6: undefined: from INFORMATION_SCHEMA.COLUMNS ^ Encountered: COLUMNS Expected: DEFAULT, IDENTIFIER CAUSED BY: Exception: Syntax error”

declare @SQL  nvarchar(max)
set @SQL = ''
;with cols as (
select Table_Schema, Table_Name, Column_Name, Row_Number() over(partition by 
Table_Schema, Table_Name
order by ORDINAL_POSITION) as RowNum

select @SQL = @SQL + case when RowNum = 1 then '' else ' union all ' end
+ ' select ''' + Column_Name + ''' as Column_Name, count(distinct ' + quotename (Column_Name) + ' ) 
As DistinctCountValue, 
count( '+ quotename (Column_Name) + ') as CountValue FROM ' + quotename (Table_Schema) + '.' + 
quotename (Table_Name)
from cols
where Table_Name = 'my_table_name' --print 

execute (@SQL)

Does INFORMATION_SCHEMA.COLUMNS exist? Probably not, and one way could be to execute some queries like ‘SHOW TABLES’, ‘DESCRIBE TableA’ etc to build you metadata first.