Python django.db.models.sql.Query() Examples

def _find_subqueries_in_where(children):
    for child in children:
        child_class = child.__class__
        if child_class is WhereNode:
            for grand_child in _find_subqueries_in_where(child.children):
                yield grand_child
        elif child_class is ExtraWhere:
            raise IsRawQuery
        elif child_class is NothingNode:
            pass
        else:
            rhs = child.rhs
            rhs_class = rhs.__class__
            if rhs_class is Query:
                yield rhs
            elif rhs_class is QuerySet:
                yield rhs.query
            elif rhs_class is Subquery or rhs_class is Exists:
                try:
                    yield rhs.query
                except:
                    yield rhs.queryset.query
            elif rhs_class in UNCACHABLE_FUNCS:
                raise UncachableQuery 

def __init__(self, model=None, query=None, using=None):
        self.model = model
        # EmptyQuerySet instantiates QuerySet with model as None
        self._db = using
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._iter = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = []
        self._prefetch_done = False
        self._known_related_objects = {}        # {rel_field, {pk: rel_obj}}

    ########################
    # PYTHON MAGIC METHODS #
    ######################## 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = ()
        self._prefetch_done = False
        self._known_related_objects = {}  # {rel_field: {pk: rel_obj}}
        self._iterable_class = ModelIterable
        self._fields = None 

def q_mentioned_fields(q, model):
    """Returns list of field names mentioned in Q object.

    Q(a__isnull=True, b=F('c')) -> ['a', 'b', 'c']
    """
    query = Query(model)
    where = query._add_q(q, used_aliases=set(), allow_joins=False)[0]
    return list(sorted(set(expression_mentioned_fields(where)))) 

def q_to_sql(q, model, schema_editor):
    # Q -> SQL conversion based on code from Ian Foote's Check Constraints pull request:
    # https://github.com/django/django/pull/7615/

    query = Query(model)
    where = query._add_q(q, used_aliases=set(), allow_joins=False)[0]
    connection = schema_editor.connection
    compiler = connection.ops.compiler('SQLCompiler')(query, connection, 'default')
    sql, params = where.as_sql(compiler, connection)
    params = tuple(map(schema_editor.quote_value, params))
    where_sql = sql % params
    return where_sql 

def __iter__(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()

            # Find out which model's fields are not present in the query.
            skip = set()
            for field in self.model._meta.fields:
                if field.attname not in model_init_names:
                    skip.add(field.attname)
            if skip:
                if self.model._meta.pk.attname in skip:
                    raise InvalidQuery('Raw query must include the primary key')
            model_cls = self.model
            fields = [self.model_fields.get(c) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            for values in query:
                if converters:
                    values = compiler.apply_converters(values, converters)
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close() 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = ()
        self._prefetch_done = False
        self._known_related_objects = {}  # {rel_field: {pk: rel_obj}}
        self._iterable_class = ModelIterable
        self._fields = None 

def __iter__(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()

            # Find out which model's fields are not present in the query.
            skip = set()
            for field in self.model._meta.fields:
                if field.attname not in model_init_names:
                    skip.add(field.attname)
            if skip:
                if self.model._meta.pk.attname in skip:
                    raise InvalidQuery('Raw query must include the primary key')
                model_cls = deferred_class_factory(self.model, skip)
            else:
                model_cls = self.model
            fields = [self.model_fields.get(c) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            for values in query:
                if converters:
                    values = compiler.apply_converters(values, converters)
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close() 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = []
        self._prefetch_done = False
        self._known_related_objects = {}  # {rel_field, {pk: rel_obj}}
        self._iterable_class = ModelIterable
        self._fields = None 

def __iter__(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()

            # Find out which model's fields are not present in the query.
            skip = set()
            for field in self.model._meta.fields:
                if field.attname not in model_init_names:
                    skip.add(field.attname)
            if skip:
                if self.model._meta.pk.attname in skip:
                    raise InvalidQuery('Raw query must include the primary key')
            model_cls = self.model
            fields = [self.model_fields.get(c) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            for values in query:
                if converters:
                    values = compiler.apply_converters(values, converters)
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close() 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = []
        self._prefetch_done = False
        self._known_related_objects = {}        # {rel_field, {pk: rel_obj}} 

def get_content_type_filter(self):
        # Query content_type using a "match" query. See comment in
        # Elasticsearch2Mapping.get_document for more details
        content_type = self.mapping_class(self.queryset.model).get_content_type()

        return {
            'match': {
                'content_type': content_type
            }
        } 

def iterator(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()
            if self.model._meta.pk.attname not in model_init_names:
                raise InvalidQuery('Raw query must include the primary key')
            model_cls = self.model
            fields = [self.model_fields.get(c) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            if converters:
                query = compiler.apply_converters(query, converters)
            for values in query:
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close() 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = ()
        self._prefetch_done = False
        self._known_related_objects = {}  # {rel_field: {pk: rel_obj}}
        self._iterable_class = ModelIterable
        self._fields = None 

def __iter__(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()
            if self.model._meta.pk.attname not in model_init_names:
                raise InvalidQuery('Raw query must include the primary key')
            model_cls = self.model
            fields = [self.model_fields.get(c) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            if converters:
                query = compiler.apply_converters(query, converters)
            for values in query:
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close() 

def __init__(self, model=None, query=None, using=None, hints=None):
        self.model = model
        self._db = using
        self._hints = hints or {}
        self.query = query or sql.Query(self.model)
        self._result_cache = None
        self._sticky_filter = False
        self._for_write = False
        self._prefetch_related_lookups = ()
        self._prefetch_done = False
        self._known_related_objects = {}  # {rel_field: {pk: rel_obj}}
        self._iterable_class = ModelIterable
        self._fields = None 

def __iter__(self):
        # Cache some things for performance reasons outside the loop.
        db = self.db
        compiler = connections[db].ops.compiler('SQLCompiler')(
            self.query, connections[db], db
        )

        query = iter(self.query)

        try:
            model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()

            # Find out which model's fields are not present in the query.
            skip = set()
            for field in self.model._meta.fields:
                if field.attname not in model_init_names:
                    skip.add(field.attname)
            if skip:
                if self.model._meta.pk.attname in skip:
                    raise InvalidQuery('Raw query must include the primary key')
                model_cls = deferred_class_factory(self.model, skip)
            else:
                model_cls = self.model
            fields = [self.model_fields.get(c, None) for c in self.columns]
            converters = compiler.get_converters([
                f.get_col(f.model._meta.db_table) if f else None for f in fields
            ])
            for values in query:
                if converters:
                    values = compiler.apply_converters(values, converters)
                # Associate fields to values
                model_init_values = [values[pos] for pos in model_init_pos]
                instance = model_cls.from_db(db, model_init_names, model_init_values)
                if annotation_fields:
                    for column, pos in annotation_fields:
                        setattr(instance, column, values[pos])
                yield instance
        finally:
            # Done iterating the Query. If it has its own cursor, close it.
            if hasattr(self.query, 'cursor') and self.query.cursor:
                self.query.cursor.close()