def json2schema(schema_json, commit = True, destdb = None):
"""
Creates Database, Table, and Column objects as needed to satisfy the incoming schema.
If the table is already present, assume we are updating: delete all columns and recreate from the schema.
Unless commit is false, call the required sql to create the incoming tables in the destination database.
"""
schema = json.loads(schema_json)
for dbname, table_schema in schema.iteritems():
if destdb:
dbname = destdb
try:
db = Database.objects.get(name=dbname)
except Database.DoesNotExist:
db = Database(name=dbname)
db.save()
for tablename, column_schema in table_schema.iteritems():
try:
table = Table.objects.get(db=db, name=tablename)
for column in Column.objects.filter(table=table):
column.delete()
except Table.DoesNotExist:
table = Table(db=db, name=tablename)
table.save()
for columnname, columntype in column_schema.iteritems():
column = Column(table=table, name=columnname, type=columntype)
column.save()
if commit:
model = ModelGenerator.getModel(dbname, tablename)
cursor = connections[dbname].cursor()
for sql in ModelGenerator.getSQL(model):
cursor.execute(sql)
return None
