ok, so that wasnt quite right, but i think I found 2 bugs:


1. the issue wasnt the group_concat itself. I had metadata that tried to give a URL to that column. the original XML was:

                    <column columnName="previousObs">
                        <columnTitle>Previous Obs</columnTitle>
                        <inputType>textarea</inputType>
                        <url>/query/executeQuery.view?schemaName=study&amp;
                            query.queryName=irregularObsById&amp;
                            query.Id~eq=${Id}
                            query.date~dateeq=${yesterday}
                        </url>
                    </column>

The column 'yesterday' is a date. apparently that is what was throwing the date-to-string error. Seems like that is a bug.



2. If i get rid of that column and just use:

                    <column columnName="previousObs">
                        <columnTitle>Previous Obs</columnTitle>
                        <inputType>textarea</inputType>
                        <url>/query/executeQuery.view?schemaName=study&amp;
                            query.queryName=irregularObsById&amp;
                            query.Id~eq=${Id}
                        </url>
                    </column>

then some cells render correctly. they render correctly so long as the group_concat isnt actually concating anything together. In other words if there was only 1 value for that Id, the field renders correctly, with a URL. if more than 1 value is returned for that Id, in which case those values would get joined, then I get the error. seems like a separate bug.