S02001

Error Code

S02002

Error Message

Duplicate column name: <xxx>. RefId:S02001

Probable Causes

This error occurs when executing SQL statements with duplicate column names in SELECT column (or GROUP BY column if has). The probable causes may include:

1. Duplicated names in SELECT statement, e.g.,select id, id from a or select id, val as id from a.

2. Name duplicated with the implicit alias from functions, expressions, or analytic functions, e.g., select id as sum, sum(id) over () from a.

3. Name duplicated with the implicit alias from the join results, e.g., select a.id + 1 as b_id, * from a, b where a.id = b.id.

4. Name duplicated with the DolphinDB reserved column names: col + numbers (e.g., "col1").

Solutions

1. Check the specified column names in SELECT statement or GROUP BY clause.

2. Use the as keyword to rename the column.

3. Avoid to use the DolphinDB reserved column names. You can use underscores as the prefix and suffix, e.g. "_id_" or use special symbols, e.g. "{0|V^^N3".