Re: [Sqlalchemy-tickets] [sqlalchemy] #2843: Support for IF EXISTS/IF NOT EXISTS DDL constructs

[sqlalchemy <mi...@zz...>]

#2843: Support for IF EXISTS/IF NOT EXISTS DDL constructs
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      Reporter:  remyroy      |      Owner:  zzzeek
          Type:  enhancement  |     Status:  new
      Priority:  medium       |  Milestone:  0.9.xx
     Component:  schema       |   Severity:  major - 1-3 hours
    Resolution:               |   Keywords:
Progress State:  in queue     |
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Comment (by remyroy):

 My personal use case is for migration. I'm currently migrating from using
 sqlalchemy-migrate to using alembic for schema migration. I have a bunch
 of databases for a single application which are in different states
 because they use different version of the same application which use
 different schema.

 In some cases, I would need to create tables, columns, indexes if they do
 no already exists or drop tables, columns, indexes if they already exists
 without alembic aborting. I believe the IF EXISTS/IF NOT EXISTS constructs
 to be well suited for this need.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2843#comment:7>
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