MySQL Bugs: #55918: forward engineer drops too many schemas

Bug #55918	forward engineer drops too many schemas
Submitted:	11 Aug 2010 16:12	Modified:	17 Sep 2010 13:34
Reporter:	[ name withheld ]	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Workbench: Modeling	Severity:	S2 (Serious)
Version:	5.2.26	OS:	Any
Assigned to:	Alexander Musienko	CPU Architecture:	Any

Description:
Forward Engineer can cause data loss!

I have a model that contains two schemas. When I try to forward-engineer just one schema, and filter out objects from the other schema, FE will generate a drop statement for both schemas.

How to repeat:
1. Create a model with two schemas, one table in each.
2. Open Forward Engineer wizard.
3. Check Generate DROP SCHEMA and uncheck everything else, click Next.
4. Use the table filter to pick a table from just one schema, click Next.

View the generated SQL. It will contain two DROP SCHEMA statements, rather than just the one for the schema from which the table has been selected in step 4.

fix confirmed in repository.

DROP and USE statements will now be inserted only for schemas whose objects are processed (and not filtered out)

An entry has been added to the 5.2.28 changelog:

If a model contained two schemata, and an attempt was made to forward engineer only one of the schemata by use of the object filters, then data loss could result. This happened because a DROP statement was generated for both schemata in the model, rather than just the one being forward engineered.