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https://issues.apache.org/jira/browse/MADLIB-1241?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16537753#comment-16537753
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Frank McQuillan commented on MADLIB-1241:
-----------------------------------------
Testing PR 282 , it seems if I try to drop a column that does not exist in the
source table, it does not throw an error and still generates the output table.
This could be problematic if I have a pipeline set up and make a typo on the
column name, my pipeline will continue with potentially errors.
I suggest if the specified column to drop does not exist in the source table,
then throw an error saying this.
> Drop columns
> ------------
>
> Key: MADLIB-1241
> URL: https://issues.apache.org/jira/browse/MADLIB-1241
> Project: Apache MADlib
> Issue Type: New Feature
> Components: Module: Utilities
> Reporter: Frank McQuillan
> Assignee: Rahul Iyer
> Priority: Major
> Fix For: v1.15
>
>
> Drop Columns
> Drops columns of a table.
> {code}
> dropcols(
> source_table,
> out_table,
> cols_to_drop
> )
> source_table
> TEXT. Name of the table containing the source data.
> out_table
> TEXT. Name of the generated table containing the output. If a table with the
> same name already exists, an error will be returned.
> cols_to_drop
> TEXT, default NULL. Comma-separated string of column names from the source
> table to drop. Not all columns of the source table can be dropped.
> Output
> The output table produced by the dropcols function contains the following
> columns:
> <...>
> Columns from source table, depending on which ones are kept.
> {code}
> Notes
> (1)
> The function
> http://pivotalsoftware.github.io/PDLTools/group__ArrayUtilities.html
> is similar. To do the equivalent of the PDL Tools one in MADlib, you would
> do:
> {code}
> dropcols(
> table_name,
> output_table,
> drop_columns
> )
> {code}
> (2)
> Please maintain the column order of the source table, minus the dropped
> column(s) of course.
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