hadoop - Alter hive table add or drop column

Question

I have orc table in hive I want to drop column from this table

ALTER TABLE table_name drop  col_name;

but I am getting the following exception

Error occurred executing hive query: OK FAILED: ParseException line 1:35 mismatched input 'user_id1' expecting PARTITION near 'drop' in drop partition statement

Can any one help me or provide any idea to do this? Note, I am using hive 0.14

Answer 1

You cannot drop column directly from a table using command ALTER TABLE table_name drop col_name;

The only way to drop column is using replace command. Lets say, I have a table emp with id, name and dept column. I want to drop id column of table emp. So provide all those columns which you want to be the part of table in replace columns clause. Below command will drop id column from emp table.

 ALTER TABLE emp REPLACE COLUMNS( name string, dept string);