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follow Python conventions for boolean values
True and False might be singletons and the "default" values for "boolean"
expressions, but "all" values in Python has a boolean value and should be
evaluated as such. Checking with 'is True' and 'is False' is thus confusing,
error prone and unnessarily complex.
If we anywhere rely and nullable boolean fields from the database layer and
don't want the null value to be treated as False then we should check
explicitly for null with 'is None'.
True and False might be singletons and the "default" values for "boolean"
expressions, but "all" values in Python has a boolean value and should be
evaluated as such. Checking with 'is True' and 'is False' is thus confusing,
error prone and unnessarily complex.
If we anywhere rely and nullable boolean fields from the database layer and
don't want the null value to be treated as False then we should check
explicitly for null with 'is None'.
9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 08d2dcd71666 72c525a7e7ad 9753e0907827 9753e0907827 72c525a7e7ad 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 72c525a7e7ad 72c525a7e7ad 72c525a7e7ad 72c525a7e7ad 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 | """
MySQL database specific implementations of changeset classes.
"""
from sqlalchemy.databases import mysql as sa_base
from sqlalchemy import types as sqltypes
from rhodecode.lib.dbmigrate.migrate import exceptions
from rhodecode.lib.dbmigrate.migrate.changeset import ansisql
MySQLSchemaGenerator = sa_base.MySQLDDLCompiler
class MySQLColumnGenerator(MySQLSchemaGenerator, ansisql.ANSIColumnGenerator):
pass
class MySQLColumnDropper(ansisql.ANSIColumnDropper):
pass
class MySQLSchemaChanger(MySQLSchemaGenerator, ansisql.ANSISchemaChanger):
def visit_column(self, delta):
table = delta.table
colspec = self.get_column_specification(delta.result_column)
if delta.result_column.autoincrement:
primary_keys = [c for c in table.primary_key.columns
if (c.autoincrement and
isinstance(c.type, sqltypes.Integer) and
not c.foreign_keys)]
if primary_keys:
first = primary_keys.pop(0)
if first.name == delta.current_name:
colspec += " AUTO_INCREMENT"
old_col_name = self.preparer.quote(delta.current_name, table.quote)
self.start_alter_table(table)
self.append("CHANGE COLUMN %s " % old_col_name)
self.append(colspec)
self.execute()
def visit_index(self, param):
# If MySQL can do this, I can't find how
raise exceptions.NotSupportedError("MySQL cannot rename indexes")
class MySQLConstraintGenerator(ansisql.ANSIConstraintGenerator):
pass
class MySQLConstraintDropper(MySQLSchemaGenerator, ansisql.ANSIConstraintDropper):
def visit_migrate_check_constraint(self, *p, **k):
raise exceptions.NotSupportedError("MySQL does not support CHECK"
" constraints, use triggers instead.")
class MySQLDialect(ansisql.ANSIDialect):
columngenerator = MySQLColumnGenerator
columndropper = MySQLColumnDropper
schemachanger = MySQLSchemaChanger
constraintgenerator = MySQLConstraintGenerator
constraintdropper = MySQLConstraintDropper
|