diff options
| -rw-r--r-- | django/db/backends/__init__.py | 6 | ||||
| -rw-r--r-- | django/db/backends/oracle/base.py | 118 | ||||
| -rw-r--r-- | django/db/backends/oracle/query.py | 130 |
3 files changed, 137 insertions, 117 deletions
diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py index fdbd8f7885..8917fc3b23 100644 --- a/django/db/backends/__init__.py +++ b/django/db/backends/__init__.py @@ -49,7 +49,7 @@ class BaseDatabaseFeatures(object): supports_constraints = True supports_tablespaces = False uses_case_insensitive_names = False - uses_custom_queryset = False + uses_custom_query_class = False empty_fetchmany_value = [] class BaseDatabaseOperations(object): @@ -199,11 +199,11 @@ class BaseDatabaseOperations(object): """ return 'DEFAULT' - def query_set_class(self, DefaultQuerySet): + def query_class(self, DefaultQueryClass): """ Given the default QuerySet class, returns a custom QuerySet class to use for this backend. Returns None if a custom QuerySet isn't used. - See also BaseDatabaseFeatures.uses_custom_queryset, which regulates + See also BaseDatabaseFeatures.uses_custom_query_class, which regulates whether this method is called at all. """ return None diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py index 67ff4ac8da..9b0dbf1beb 100644 --- a/django/db/backends/oracle/base.py +++ b/django/db/backends/oracle/base.py @@ -4,10 +4,10 @@ Oracle database backend for Django. Requires cx_Oracle: http://www.python.net/crew/atuining/cx_Oracle/ """ -import datetime import os from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, BaseDatabaseOperations, util +from django.db.backends.oracle import query from django.utils.datastructures import SortedDict from django.utils.encoding import smart_str, force_unicode @@ -30,7 +30,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): needs_upper_for_iops = True supports_tablespaces = True uses_case_insensitive_names = True - uses_custom_queryset = True + uses_custom_query_class = True class DatabaseOperations(BaseDatabaseOperations): def autoinc_sql(self, table, column): @@ -99,118 +99,8 @@ class DatabaseOperations(BaseDatabaseOperations): def max_name_length(self): return 30 - def query_set_class(self, DefaultQuerySet): - # Getting the base default `Query` object. - DefaultQuery = DefaultQuerySet().query.__class__ - - class OracleQuery(DefaultQuery): - def resolve_columns(self, row, fields=()): - from django.db.models.fields import DateField, DateTimeField, \ - TimeField, BooleanField, NullBooleanField, DecimalField, Field - values = [] - for value, field in map(None, row, fields): - if isinstance(value, Database.LOB): - value = value.read() - # Oracle stores empty strings as null. We need to undo this in - # order to adhere to the Django convention of using the empty - # string instead of null, but only if the field accepts the - # empty string. - if value is None and isinstance(field, Field) and field.empty_strings_allowed: - value = u'' - # Convert 1 or 0 to True or False - elif value in (1, 0) and isinstance(field, (BooleanField, NullBooleanField)): - value = bool(value) - # Convert floats to decimals - elif value is not None and isinstance(field, DecimalField): - value = util.typecast_decimal(field.format_number(value)) - # cx_Oracle always returns datetime.datetime objects for - # DATE and TIMESTAMP columns, but Django wants to see a - # python datetime.date, .time, or .datetime. We use the type - # of the Field to determine which to cast to, but it's not - # always available. - # As a workaround, we cast to date if all the time-related - # values are 0, or to time if the date is 1/1/1900. - # This could be cleaned a bit by adding a method to the Field - # classes to normalize values from the database (the to_python - # method is used for validation and isn't what we want here). - elif isinstance(value, Database.Timestamp): - # In Python 2.3, the cx_Oracle driver returns its own - # Timestamp object that we must convert to a datetime class. - if not isinstance(value, datetime.datetime): - value = datetime.datetime(value.year, value.month, value.day, value.hour, - value.minute, value.second, value.fsecond) - if isinstance(field, DateTimeField): - pass # DateTimeField subclasses DateField so must be checked first. - elif isinstance(field, DateField): - value = value.date() - elif isinstance(field, TimeField) or (value.year == 1900 and value.month == value.day == 1): - value = value.time() - elif value.hour == value.minute == value.second == value.microsecond == 0: - value = value.date() - values.append(value) - return values - - def as_sql(self, with_limits=True): - """ - Creates the SQL for this query. Returns the SQL string and list - of parameters. This is overriden from the original Query class - to accommodate Oracle's limit/offset SQL. - - If 'with_limits' is False, any limit/offset information is not - included in the query. - """ - # The `do_offset` flag indicates whether we need to construct - # the SQL needed to use limit/offset w/Oracle. - do_offset = with_limits and (self.high_mark or self.low_mark) - - # If no offsets, just return the result of the base class - # `as_sql`. - if not do_offset: - return super(OracleQuery, self).as_sql(with_limits=False) - - # `get_columns` needs to be called before `get_ordering` to - # populate `_select_alias`. - self.pre_sql_setup() - out_cols = self.get_columns() - ordering = self.get_ordering() - - # Getting the "ORDER BY" SQL for the ROW_NUMBER() result. - if ordering: - rn_orderby = ', '.join(ordering) - else: - # Oracle's ROW_NUMBER() function always requires an - # order-by clause. So we need to define a default - # order-by, since none was provided. - qn = self.quote_name_unless_alias - opts = self.model._meta - rn_orderby = '%s.%s' % (qn(opts.db_table), qn(opts.fields[0].db_column or opts.fields[0].column)) - - # Getting the selection SQL and the params, which has the `rn` - # extra selection SQL; we pop `rn` after this completes so we do - # not get the attribute on the returned models. - self.extra_select['rn'] = 'ROW_NUMBER() OVER (ORDER BY %s )' % rn_orderby - sql, params= super(OracleQuery, self).as_sql(with_limits=False) - self.extra_select.pop('rn') - - # Constructing the result SQL, using the initial select SQL - # obtained above. - result = ['SELECT * FROM (%s)' % sql] - - # Place WHERE condition on `rn` for the desired range. - result.append('WHERE rn > %d' % self.low_mark) - if self.high_mark: - result.append('AND rn <= %d' % self.high_mark) - - # Returning the SQL w/params. - return ' '.join(result), params - - from django.db import connection - class OracleQuerySet(DefaultQuerySet): - "The OracleQuerySet is overriden to use OracleQuery." - def __init__(self, model=None, query=None): - super(OracleQuerySet, self).__init__(model=model, query=query) - self.query = query or OracleQuery(self.model, connection) - return OracleQuerySet + def query_class(self, DefaultQueryClass): + return query.query_class(DefaultQueryClass, Database) def quote_name(self, name): # SQL92 requires delimited (quoted) names to be case-sensitive. When diff --git a/django/db/backends/oracle/query.py b/django/db/backends/oracle/query.py new file mode 100644 index 0000000000..c127ba9cfc --- /dev/null +++ b/django/db/backends/oracle/query.py @@ -0,0 +1,130 @@ +""" +Custom Query class for this backend (a derivative of +django.db.models.sql.query.Query). +""" + +import datetime + +from django.db.backends import util + +# Cache. Maps default query class to new Oracle query class. +_classes = {} + +def query_class(QueryClass, Database): + """ + Returns a custom djang.db.models.sql.query.Query subclass that is + appropraite for Oracle. + + The 'Database' module (cx_Oracle) is passed in here so that all the setup + required to import it only needs to be done by the calling module. + """ + global _classes + try: + return _classes[QueryClass] + except KeyError: + pass + + class OracleQuery(QueryClass): + def resolve_columns(self, row, fields=()): + from django.db.models.fields import DateField, DateTimeField, \ + TimeField, BooleanField, NullBooleanField, DecimalField, Field + values = [] + for value, field in map(None, row, fields): + if isinstance(value, Database.LOB): + value = value.read() + # Oracle stores empty strings as null. We need to undo this in + # order to adhere to the Django convention of using the empty + # string instead of null, but only if the field accepts the + # empty string. + if value is None and isinstance(field, Field) and field.empty_strings_allowed: + value = u'' + # Convert 1 or 0 to True or False + elif value in (1, 0) and isinstance(field, (BooleanField, NullBooleanField)): + value = bool(value) + # Convert floats to decimals + elif value is not None and isinstance(field, DecimalField): + value = util.typecast_decimal(field.format_number(value)) + # cx_Oracle always returns datetime.datetime objects for + # DATE and TIMESTAMP columns, but Django wants to see a + # python datetime.date, .time, or .datetime. We use the type + # of the Field to determine which to cast to, but it's not + # always available. + # As a workaround, we cast to date if all the time-related + # values are 0, or to time if the date is 1/1/1900. + # This could be cleaned a bit by adding a method to the Field + # classes to normalize values from the database (the to_python + # method is used for validation and isn't what we want here). + elif isinstance(value, Database.Timestamp): + # In Python 2.3, the cx_Oracle driver returns its own + # Timestamp object that we must convert to a datetime class. + if not isinstance(value, datetime.datetime): + value = datetime.datetime(value.year, value.month, value.day, value.hour, + value.minute, value.second, value.fsecond) + if isinstance(field, DateTimeField): + pass # DateTimeField subclasses DateField so must be checked first. + elif isinstance(field, DateField): + value = value.date() + elif isinstance(field, TimeField) or (value.year == 1900 and value.month == value.day == 1): + value = value.time() + elif value.hour == value.minute == value.second == value.microsecond == 0: + value = value.date() + values.append(value) + return values + + def as_sql(self, with_limits=True): + """ + Creates the SQL for this query. Returns the SQL string and list + of parameters. This is overriden from the original Query class + to accommodate Oracle's limit/offset SQL. + + If 'with_limits' is False, any limit/offset information is not + included in the query. + """ + # The `do_offset` flag indicates whether we need to construct + # the SQL needed to use limit/offset w/Oracle. + do_offset = with_limits and (self.high_mark or self.low_mark) + + # If no offsets, just return the result of the base class + # `as_sql`. + if not do_offset: + return super(OracleQuery, self).as_sql(with_limits=False) + + # `get_columns` needs to be called before `get_ordering` to + # populate `_select_alias`. + self.pre_sql_setup() + out_cols = self.get_columns() + ordering = self.get_ordering() + + # Getting the "ORDER BY" SQL for the ROW_NUMBER() result. + if ordering: + rn_orderby = ', '.join(ordering) + else: + # Oracle's ROW_NUMBER() function always requires an + # order-by clause. So we need to define a default + # order-by, since none was provided. + qn = self.quote_name_unless_alias + opts = self.model._meta + rn_orderby = '%s.%s' % (qn(opts.db_table), qn(opts.fields[0].db_column or opts.fields[0].column)) + + # Getting the selection SQL and the params, which has the `rn` + # extra selection SQL; we pop `rn` after this completes so we do + # not get the attribute on the returned models. + self.extra_select['rn'] = 'ROW_NUMBER() OVER (ORDER BY %s )' % rn_orderby + sql, params= super(OracleQuery, self).as_sql(with_limits=False) + self.extra_select.pop('rn') + + # Constructing the result SQL, using the initial select SQL + # obtained above. + result = ['SELECT * FROM (%s)' % sql] + + # Place WHERE condition on `rn` for the desired range. + result.append('WHERE rn > %d' % self.low_mark) + if self.high_mark: + result.append('AND rn <= %d' % self.high_mark) + + # Returning the SQL w/params. + return ' '.join(result), params + + _classes[QueryClass] = OracleQuery + return OracleQuery + |