I need to add a column with varchar2 data type in teradata sql , 
for example
ALTER TABLE table_name ADD column_name varchar2 (20); 
But in teradata its not taking varchar2 as a defined type name.
I need to add a column with varchar2 data type in teradata sql , 
for example
ALTER TABLE table_name ADD column_name varchar2 (20); 
But in teradata its not taking varchar2 as a defined type name.
varchar2 is an Oracle-specific datatype, not defined in the ANSI SQL standard. You should use the standard varchar type instead:
ALTER TABLE table_name ADD column_name VARCHAR(20);
 
    
    I think you should use NVARCHAR(20) - pay attention to that extra N in the type name, as it allows you to store Unicode strings.
 
    
    