This is in CVS, but I assume it applies to all versions. It's preventable, but still an issue.

If you create a content-type with 4 fields and then create content in that type, there are problems in the mySQL that arise if the administrator then deletes one of the fields from the content-type definition.

Here's a sample error:

You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near ' flexinode_24.serialized_data AS flexinode_24, flexinode_20.num query: SELECT flexinode_22.textual_data AS flexinode_22, flexinode_23.textual_data AS flexinode_23, , flexinode_24.serialized_data AS flexinode_24, flexinode_20.numeric_data AS flexinode_20, flexinode_21.textual_data AS flexinode_21, flexinode_21.numeric_data AS flexinode_21_format, flexinode_27.textual_data AS flexinode_27 FROM node n LEFT JOIN flexinode_data flexinode_22 ON n.nid = flexinode_22.nid AND flexinode_22.field_id = 22 LEFT JOIN flexinode_data flexinode_23 ON n.nid = flexinode_23.nid AND flexinode_23.field_id = 23 LEFT JOIN flexinode_data flexinode_28 ON n.nid = flexinode_28.nid AND flexinode_28.field_id = 28 LEFT JOIN flexinode_data flexinode_24 ON n.nid = flexinode_24.nid AND flexinode_24.field_id = 24 LEFT JOIN flexinode_data flexinode_20 ON n.nid = flexinode_20.nid AND flexinode_20.field_id = 20 in /[server_path_edited]/includes/database.mysql.inc on line 66.

In this case, I had created (for testing) and then deleted FIELD_ID 28. When trying to load a page containing this content-type, the error is returned.

Perhaps there should be a mechnism for handling this issue, or at least warning the administrator that the field to be deleted contains data