How to disable Foreign Keys to clear database

[Greg]

Hi,

I was naively trying to clear a db earlier in the day and I ran into this problem: 'Cannot delete or update a parent row: a foreign key constraint fails'

So as anyone would do I've been searching online and through the documentation on how to turn the foreign keys off, on delete = Cascade, delete orphan-cascade what have you. So many hours and many stack traces later I'd like to ask your help in this matter

def cleanMapping(self, dbName):
 
      connection =  self.dbEngines[dbName].connect()
      trans = connection.begin()
      
      for my_table in reversed(self.dbMetaData[dbName].tables.values()):
         keys= my_table.foreign_keys
         for column in my_table.columns:
            for key in keys:

               my_table = Table(my_table, self.dbMetaData[dbName],
                           Column(column, Integer,
                           ForeignKey(key, onupdate="CASCADE", ondelete = "CASCADE")
                           ,primary_key=True))   
               connection.execute(my_table.delete())
      
      trans.commit()

So I'm fresh out of ideas; Everytime I try using this code I get "sqlalchemy.exc.ArgumentError: Column object already assigned to Table <col>"

[GHZ]

There is a recipe for dropping FK constraints:

http://www.sqlalchemy.org/trac/wiki/UsageRecipes

did you find that?

In addition, if you wanted to keep the FKs enabled, there is an example here using Metadata.sorted_tables, to get the table list in dependency order.

http://docs.sqlalchemy.org/en/rel_0_7/core/schema.html?highlight=sorted_tables#reflecting-all-tables-at-once 

[Gregory Rehm]

Thanks so much! that worked great. It seems like google directed me
everywhere except to the recipes.

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