frappe/frappe/model/db_query.py

# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# License: MIT. See LICENSE
"""build query for doclistview and return results"""

from typing import List
import frappe.defaults
from frappe.query_builder.utils import Column
import frappe.share
from frappe import _
import frappe.permissions
from datetime import datetime
import frappe, json, copy, re
from frappe.model import optional_fields
from frappe.model.utils.user_settings import get_user_settings, update_user_settings
from frappe.utils import flt, cint, get_time, make_filter_tuple, get_filter, add_to_date, cstr, get_timespan_date_range
from frappe.model.meta import get_table_columns
from frappe.core.doctype.server_script.server_script_utils import get_server_script_map

class DatabaseQuery(object):
	def __init__(self, doctype, user=None):
		self.doctype = doctype
		self.tables = []
		self.conditions = []
		self.or_conditions = []
		self.fields = None
		self.user = user or frappe.session.user
		self.ignore_ifnull = False
		self.flags = frappe._dict()
		self.reference_doctype = None

	def execute(self, fields=None, filters=None, or_filters=None,
		docstatus=None, group_by=None, order_by="KEEP_DEFAULT_ORDERING", limit_start=False,
		limit_page_length=None, as_list=False, with_childnames=False, debug=False,
		ignore_permissions=False, user=None, with_comment_count=False,
		join='left join', distinct=False, start=None, page_length=None, limit=None,
		ignore_ifnull=False, save_user_settings=False, save_user_settings_fields=False,
		update=None, add_total_row=None, user_settings=None, reference_doctype=None,
		run=True, strict=True, pluck=None, ignore_ddl=False, parent_doctype=None) -> List:

		if (
			not ignore_permissions
			and not frappe.has_permission(self.doctype, "select", user=user, parent_doctype=parent_doctype)
			and not frappe.has_permission(self.doctype, "read", user=user, parent_doctype=parent_doctype)
		):
			frappe.flags.error_message = _('Insufficient Permission for {0}').format(frappe.bold(self.doctype))
			raise frappe.PermissionError(self.doctype)

		# filters and fields swappable
		# its hard to remember what comes first
		if (
			isinstance(fields, dict)
			or (
				fields
				and isinstance(fields, list)
				and isinstance(fields[0], list)
			)
		):
			# if fields is given as dict/list of list, its probably filters
			filters, fields = fields, filters

		elif fields and isinstance(filters, list) \
			and len(filters) > 1 and isinstance(filters[0], str):
			# if `filters` is a list of strings, its probably fields
			filters, fields = fields, filters

		if fields:
			self.fields = fields
		else:
			self.fields =  [f"`tab{self.doctype}`.`{pluck or 'name'}`"]

		if start: limit_start = start
		if page_length: limit_page_length = page_length
		if limit: limit_page_length = limit

		self.filters = filters or []
		self.or_filters = or_filters or []
		self.docstatus = docstatus or []
		self.group_by = group_by
		self.order_by = order_by
		self.limit_start = cint(limit_start)
		self.limit_page_length = cint(limit_page_length) if limit_page_length else None
		self.with_childnames = with_childnames
		self.debug = debug
		self.join = join
		self.distinct = distinct
		self.as_list = as_list
		self.ignore_ifnull = ignore_ifnull
		self.flags.ignore_permissions = ignore_permissions
		self.user = user or frappe.session.user
		self.update = update
		self.user_settings_fields = copy.deepcopy(self.fields)
		self.run = run
		self.strict = strict
		self.ignore_ddl = ignore_ddl

		# for contextual user permission check
		# to determine which user permission is applicable on link field of specific doctype
		self.reference_doctype = reference_doctype or self.doctype

		if user_settings:
			self.user_settings = json.loads(user_settings)

		self.columns = self.get_table_columns()

		# no table & ignore_ddl, return
		if not self.columns: return []

		result = self.build_and_run()

		if with_comment_count and not as_list and self.doctype:
			self.add_comment_count(result)

		if save_user_settings:
			self.save_user_settings_fields = save_user_settings_fields
			self.update_user_settings()

		if pluck:
			return [d[pluck] for d in result]

		return result

	def build_and_run(self):
		args = self.prepare_args()
		args.limit = self.add_limit()

		if args.conditions:
			args.conditions = "where " + args.conditions

		if self.distinct:
			args.fields = 'distinct ' + args.fields
			args.order_by = '' # TODO: recheck for alternative

		# Postgres requires any field that appears in the select clause to also
		# appear in the order by and group by clause
		if frappe.db.db_type == 'postgres' and args.order_by and args.group_by:
			args = self.prepare_select_args(args)

		query = """select %(fields)s
			from %(tables)s
			%(conditions)s
			%(group_by)s
			%(order_by)s
			%(limit)s""" % args

		return frappe.db.sql(query, as_dict=not self.as_list, debug=self.debug,
				update=self.update, ignore_ddl=self.ignore_ddl, run=self.run)

	def prepare_args(self):
		self.parse_args()
		self.sanitize_fields()
		self.extract_tables()
		self.set_optional_columns()
		self.build_conditions()

		args = frappe._dict()

		if self.with_childnames:
			for t in self.tables:
				if t != "`tab" + self.doctype + "`":
					self.fields.append(t + ".name as '%s:name'" % t[4:-1])

		# query dict
		args.tables = self.tables[0]

		# left join parent, child tables
		for child in self.tables[1:]:
			parent_name = self.cast_name(f"{self.tables[0]}.name")
			args.tables += f" {self.join} {child} on ({child}.parent = {parent_name})"

		if self.grouped_or_conditions:
			self.conditions.append(f"({' or '.join(self.grouped_or_conditions)})")

		args.conditions = ' and '.join(self.conditions)

		if self.or_conditions:
			args.conditions += (' or ' if args.conditions else "") + \
				' or '.join(self.or_conditions)

		self.set_field_tables()

		fields = []

		# Wrapping fields with grave quotes to allow support for sql keywords
		# TODO: Add support for wrapping fields with sql functions and distinct keyword
		for field in self.fields:
			stripped_field = field.strip().lower()
			skip_wrapping = any([
				stripped_field.startswith(("`", "*", '"', "'")),
				"(" in stripped_field,
				"distinct" in stripped_field,
			])
			if skip_wrapping:
				fields.append(field)
			elif "as" in field.lower().split(" "):
				col, _, new = field.split()
				fields.append(f"`{col}` as {new}")
			else:
				fields.append(f"`{field}`")

		args.fields = ", ".join(fields)

		self.set_order_by(args)

		self.validate_order_by_and_group_by(args.order_by)
		args.order_by = args.order_by and (" order by " + args.order_by) or ""

		self.validate_order_by_and_group_by(self.group_by)
		args.group_by = self.group_by and (" group by " + self.group_by) or ""

		return args

	def prepare_select_args(self, args):
		order_field = re.sub(r"\ order\ by\ |\ asc|\ ASC|\ desc|\ DESC", "", args.order_by)

		if order_field not in args.fields:
			extracted_column = order_column = order_field.replace("`", "")
			if "." in extracted_column:
				extracted_column = extracted_column.split(".")[1]

			args.fields += f", MAX({extracted_column}) as `{order_column}`"
			args.order_by = args.order_by.replace(order_field, f"`{order_column}`")

		return args

	def parse_args(self):
		"""Convert fields and filters from strings to list, dicts"""
		if isinstance(self.fields, str):
			if self.fields == "*":
				self.fields = ["*"]
			else:
				try:
					self.fields = json.loads(self.fields)
				except ValueError:
					self.fields = [f.strip() for f in self.fields.split(",")]

		# remove empty strings / nulls in fields
		self.fields = [f for f in self.fields if f]

		for filter_name in ["filters", "or_filters"]:
			filters = getattr(self, filter_name)
			if isinstance(filters, str):
				filters = json.loads(filters)

			if isinstance(filters, dict):
				fdict = filters
				filters = []
				for key, value in fdict.items():
					filters.append(make_filter_tuple(self.doctype, key, value))
			setattr(self, filter_name, filters)

	def sanitize_fields(self):
		'''
			regex : ^.*[,();].*
			purpose : The regex will look for malicious patterns like `,`, '(', ')', '@', ;' in each
					field which may leads to sql injection.
			example :
				field = "`DocType`.`issingle`, version()"
			As field contains `,` and mysql function `version()`, with the help of regex
			the system will filter out this field.
		'''

		sub_query_regex = re.compile("^.*[,();@].*")
		blacklisted_keywords = ['select', 'create', 'insert', 'delete', 'drop', 'update', 'case', 'show']
		blacklisted_functions = ['concat', 'concat_ws', 'if', 'ifnull', 'nullif', 'coalesce',
			'connection_id', 'current_user', 'database', 'last_insert_id', 'session_user',
			'system_user', 'user', 'version', 'global']

		def _raise_exception():
			frappe.throw(_('Use of sub-query or function is restricted'), frappe.DataError)

		def _is_query(field):
			if re.compile(r"^(select|delete|update|drop|create)\s").match(field):
				_raise_exception()

			elif re.compile(r"\s*[0-9a-zA-z]*\s*( from | group by | order by | where | join )").match(field):
				_raise_exception()

		for field in self.fields:
			if sub_query_regex.match(field):
				if any(keyword in field.lower().split() for keyword in blacklisted_keywords):
					_raise_exception()

				if any(f"({keyword}" in field.lower() for keyword in blacklisted_keywords):
					_raise_exception()

				if any(f"{keyword}(" in field.lower() for keyword in blacklisted_functions):
					_raise_exception()

				if '@' in field.lower():
					# prevent access to global variables
					_raise_exception()

			if re.compile(r"[0-9a-zA-Z]+\s*'").match(field):
				_raise_exception()

			if re.compile(r"[0-9a-zA-Z]+\s*,").match(field):
				_raise_exception()

			_is_query(field)

			if self.strict:
				if re.compile(r".*/\*.*").match(field):
					frappe.throw(_('Illegal SQL Query'))

				if re.compile(r".*\s(union).*\s").match(field.lower()):
					frappe.throw(_('Illegal SQL Query'))

	def extract_tables(self):
		"""extract tables from fields"""
		self.tables = [f"`tab{self.doctype}`"]
		sql_functions = [
			"dayofyear(",
			"extract(",
			"locate(",
			"strpos(",
			"count(",
			"sum(",
			"avg(",
		]
		# add tables from fields
		if self.fields:
			for i, field in enumerate(self.fields):
				# add cast in locate/strpos
				func_found = False
				for func in sql_functions:
					if func in field.lower():
						self.fields[i] = self.cast_name(field, func)
						func_found = True
						break

				if func_found or not ("tab" in field and "." in field):
					continue

				table_name = field.split('.')[0]

				if table_name.lower().startswith('group_concat('):
					table_name = table_name[13:]
				if not table_name[0]=='`':
					table_name = f"`{table_name}`"
				if table_name not in self.tables:
					self.append_table(table_name)

	def cast_name(self, column: str, sql_function: str = "",) -> str:
		if frappe.db.db_type == "postgres":
			if "name" in column.lower():
				if "cast(" not in column.lower() or "::" not in column:
					if not sql_function:
						return f"cast({column} as varchar)"

					elif sql_function == "locate(":
						return re.sub(
							r'locate\(([^,]+),([^)]+)\)',
							r'locate(\1, cast(\2 as varchar))',
							column,
							flags=re.IGNORECASE
						)

					elif sql_function == "strpos(":
						return re.sub(
							r'strpos\(([^,]+),([^)]+)\)',
							r'strpos(cast(\1 as varchar), \2)',
							column,
							flags=re.IGNORECASE
						)

					elif sql_function == "ifnull(":
						return re.sub(
							r"ifnull\(([^,]+)",
							r"ifnull(cast(\1 as varchar)",
							column,
							flags=re.IGNORECASE
						)

		return column

	def append_table(self, table_name):
		self.tables.append(table_name)
		doctype = table_name[4:-1]
		ptype = 'select' if frappe.only_has_select_perm(doctype) else 'read'

		if not self.flags.ignore_permissions and \
			not frappe.has_permission(doctype, ptype=ptype, parent_doctype=self.doctype):
			frappe.flags.error_message = _('Insufficient Permission for {0}').format(frappe.bold(doctype))
			raise frappe.PermissionError(doctype)

	def set_field_tables(self):
		'''If there are more than one table, the fieldname must not be ambiguous.
		If the fieldname is not explicitly mentioned, set the default table'''
		def _in_standard_sql_methods(field):
			methods = ('count(', 'avg(', 'sum(', 'extract(', 'dayofyear(')
			return field.lower().startswith(methods)

		if len(self.tables) > 1:
			for idx, field in enumerate(self.fields):
				if '.' not in field and not _in_standard_sql_methods(field):
					self.fields[idx] = f"{self.tables[0]}.{field}"

	def get_table_columns(self):
		try:
			return get_table_columns(self.doctype)
		except frappe.db.TableMissingError:
			if self.ignore_ddl:
				return None
			else:
				raise

	def set_optional_columns(self):
		"""Removes optional columns like `_user_tags`, `_comments` etc. if not in table"""
		# remove from fields
		to_remove = []
		for fld in self.fields:
			for f in optional_fields:
				if f in fld and not f in self.columns:
					to_remove.append(fld)

		for fld in to_remove:
			del self.fields[self.fields.index(fld)]

		# remove from filters
		to_remove = []
		for each in self.filters:
			if isinstance(each, str):
				each = [each]

			for element in each:
				if element in optional_fields and element not in self.columns:
					to_remove.append(each)

		for each in to_remove:
			if isinstance(self.filters, dict):
				del self.filters[each]
			else:
				self.filters.remove(each)

	def build_conditions(self):
		self.conditions = []
		self.grouped_or_conditions = []
		self.build_filter_conditions(self.filters, self.conditions)
		self.build_filter_conditions(self.or_filters, self.grouped_or_conditions)

		# match conditions
		if not self.flags.ignore_permissions:
			match_conditions = self.build_match_conditions()
			if match_conditions:
				self.conditions.append(f"({match_conditions})")

	def build_filter_conditions(self, filters, conditions, ignore_permissions=None):
		"""build conditions from user filters"""
		if ignore_permissions is not None:
			self.flags.ignore_permissions = ignore_permissions

		if isinstance(filters, dict):
			filters = [filters]

		for f in filters:
			if isinstance(f, str):
				conditions.append(f)
			else:
				conditions.append(self.prepare_filter_condition(f))

	def prepare_filter_condition(self, f):
		"""Returns a filter condition in the format:
				ifnull(`tabDocType`.`fieldname`, fallback) operator "value"
		"""

		# TODO: refactor

		from frappe.boot import get_additional_filters_from_hooks
		additional_filters_config = get_additional_filters_from_hooks()
		f = get_filter(self.doctype, f, additional_filters_config)

		tname = ('`tab' + f.doctype + '`')
		if tname not in self.tables:
			self.append_table(tname)

		if 'ifnull(' in f.fieldname:
			column_name = self.cast_name(f.fieldname, "ifnull(")
		else:
			column_name = self.cast_name(f"{tname}.`{f.fieldname}`")

		if f.operator.lower() in additional_filters_config:
			f.update(get_additional_filter_field(additional_filters_config, f, f.value))

		meta = frappe.get_meta(f.doctype)
		can_be_null = True

		# prepare in condition
		if f.operator.lower() in ('ancestors of', 'descendants of', 'not ancestors of', 'not descendants of'):
			values = f.value or ''

			# TODO: handle list and tuple
			# if not isinstance(values, (list, tuple)):
			# 	values = values.split(",")

			field = meta.get_field(f.fieldname)
			ref_doctype = field.options if field else f.doctype

			lft, rgt = '', ''
			if f.value:
				lft, rgt = frappe.db.get_value(ref_doctype, f.value, ["lft", "rgt"])

			# Get descendants elements of a DocType with a tree structure
			if f.operator.lower() in ('descendants of', 'not descendants of') :
				result = frappe.get_all(ref_doctype, filters={
					'lft': ['>', lft],
					'rgt': ['<', rgt]
				}, order_by='`lft` ASC')
			else :
				# Get ancestor elements of a DocType with a tree structure
				result = frappe.get_all(ref_doctype, filters={
					'lft': ['<', lft],
					'rgt': ['>', rgt]
				}, order_by='`lft` DESC')

			fallback = "''"
			value = [frappe.db.escape((cstr(v.name) or '').strip(), percent=False) for v in result]
			if len(value):
				value = f"({', '.join(value)})"
			else:
				value = "('')"

			# changing operator to IN as the above code fetches all the parent / child values and convert into tuple
			# which can be directly used with IN operator to query.
			f.operator = 'not in' if f.operator.lower() in ('not ancestors of', 'not descendants of') else 'in'

		elif f.operator.lower() in ('in', 'not in'):
			values = f.value or ''
			if isinstance(values, str):
				values = values.split(",")

			fallback = "''"
			value = [frappe.db.escape((cstr(v) or '').strip(), percent=False) for v in values]
			if len(value):
				value = f"({', '.join(value)})"
			else:
				value = "('')"

		else:
			df = meta.get("fields", {"fieldname": f.fieldname})
			df = df[0] if df else None

			if df and df.fieldtype in ("Check", "Float", "Int", "Currency", "Percent"):
				can_be_null = False

			if f.operator.lower() in ('previous', 'next', 'timespan'):
				date_range = get_date_range(f.operator.lower(), f.value)
				f.operator = "Between"
				f.value = date_range
				fallback = "'0001-01-01 00:00:00'"

			if f.operator in ('>', '<') and (f.fieldname in ('creation', 'modified')):
				value = cstr(f.value)
				fallback = "'0001-01-01 00:00:00'"

			elif f.operator.lower() in ('between') and \
				(f.fieldname in ('creation', 'modified') or
				(df and (df.fieldtype=="Date" or df.fieldtype=="Datetime"))):

				value = get_between_date_filter(f.value, df)
				fallback = "'0001-01-01 00:00:00'"

			elif f.operator.lower() == "is":
				if f.value == 'set':
					f.operator = '!='
				elif f.value == 'not set':
					f.operator = '='

				value = ""
				fallback = "''"
				can_be_null = True

				if 'ifnull' not in column_name.lower():
					column_name = f'ifnull({column_name}, {fallback})'

			elif df and df.fieldtype=="Date":
				value = frappe.db.format_date(f.value)
				fallback = "'0001-01-01'"

			elif (df and df.fieldtype=="Datetime") or isinstance(f.value, datetime):
				value = frappe.db.format_datetime(f.value)
				fallback = "'0001-01-01 00:00:00'"

			elif df and df.fieldtype=="Time":
				value = get_time(f.value).strftime("%H:%M:%S.%f")
				fallback = "'00:00:00'"

			elif f.operator.lower() in ("like", "not like") or (isinstance(f.value, str) and
				(not df or df.fieldtype not in ["Float", "Int", "Currency", "Percent", "Check"])):
					value = "" if f.value is None else f.value
					fallback = "''"

					if f.operator.lower() in ("like", "not like") and isinstance(value, str):
						# because "like" uses backslash (\) for escaping
						value = value.replace("\\", "\\\\").replace("%", "%%")

			elif f.operator == '=' and df and df.fieldtype in ['Link', 'Data']: # TODO: Refactor if possible
				value = f.value or "''"
				fallback = "''"

			elif f.fieldname == 'name':
				value = f.value or "''"
				fallback = "''"

			else:
				value = flt(f.value)
				fallback = 0

			if isinstance(f.value, Column):
				can_be_null = False	# added to avoid the ifnull/coalesce addition
				quote = '"' if frappe.conf.db_type == 'postgres' else "`"
				value = f"{tname}.{quote}{f.value.name}{quote}"

			# escape value
			elif isinstance(value, str) and f.operator.lower() != 'between':
				value = f"{frappe.db.escape(value, percent=False)}"

		if (
			self.ignore_ifnull
			or not can_be_null
			or (f.value and f.operator.lower() in ('=', 'like'))
			or 'ifnull(' in column_name.lower()
		):
			if f.operator.lower() == 'like' and frappe.conf.get('db_type') == 'postgres':
				f.operator = 'ilike'
			condition = f'{column_name} {f.operator} {value}'
		else:
			condition = f'ifnull({column_name}, {fallback}) {f.operator} {value}'

		return condition

	def build_match_conditions(self, as_condition=True):
		"""add match conditions if applicable"""
		self.match_filters = []
		self.match_conditions = []
		only_if_shared = False
		if not self.user:
			self.user = frappe.session.user

		if not self.tables: self.extract_tables()

		meta = frappe.get_meta(self.doctype)
		role_permissions = frappe.permissions.get_role_permissions(meta, user=self.user)
		self.shared = frappe.share.get_shared(self.doctype, self.user)

		if (
			not meta.istable and
			not (role_permissions.get("select") or role_permissions.get("read")) and
			not self.flags.ignore_permissions and
			not has_any_user_permission_for_doctype(self.doctype, self.user, self.reference_doctype)
		):
			only_if_shared = True
			if not self.shared:
				frappe.throw(_("No permission to read {0}").format(self.doctype), frappe.PermissionError)
			else:
				self.conditions.append(self.get_share_condition())

		else:
			# skip user perm check if owner constraint is required
			if requires_owner_constraint(role_permissions):
				self.match_conditions.append(
					f"`tab{self.doctype}`.`owner` = {frappe.db.escape(self.user, percent=False)}"
				)

			# add user permission only if role has read perm
			elif role_permissions.get("read") or role_permissions.get("select"):
				# get user permissions
				user_permissions = frappe.permissions.get_user_permissions(self.user)
				self.add_user_permissions(user_permissions)

		if as_condition:
			conditions = ""
			if self.match_conditions:
				# will turn out like ((blog_post in (..) and blogger in (...)) or (blog_category in (...)))
				conditions = "((" + ") or (".join(self.match_conditions) + "))"

			doctype_conditions = self.get_permission_query_conditions()
			if doctype_conditions:
				conditions += (' and ' + doctype_conditions) if conditions else doctype_conditions

			# share is an OR condition, if there is a role permission
			if not only_if_shared and self.shared and conditions:
				conditions =  f"({conditions}) or ({self.get_share_condition()})"

			return conditions

		else:
			return self.match_filters

	def get_share_condition(self):
		return f"`tab{self.doctype}`.name in ({', '.join(frappe.db.escape(s, percent=False) for s in self.shared)})"

	def add_user_permissions(self, user_permissions):
		meta = frappe.get_meta(self.doctype)
		doctype_link_fields = []
		doctype_link_fields = meta.get_link_fields()

		# append current doctype with fieldname as 'name' as first link field
		doctype_link_fields.append(dict(
			options=self.doctype,
			fieldname='name',
		))

		match_filters = {}
		match_conditions = []
		for df in doctype_link_fields:
			if df.get('ignore_user_permissions'): continue

			user_permission_values = user_permissions.get(df.get('options'), {})

			if user_permission_values:
				docs = []
				if frappe.get_system_settings("apply_strict_user_permissions"):
					condition = ""
				else:
					empty_value_condition = f"ifnull(`tab{self.doctype}`.`{df.get('fieldname')}`, '')=''"
					condition = empty_value_condition + " or "

				for permission in user_permission_values:
					if not permission.get('applicable_for'):
						docs.append(permission.get('doc'))

					# append docs based on user permission applicable on reference doctype
					# this is useful when getting list of docs from a link field
					# in this case parent doctype of the link
					# will be the reference doctype

					elif df.get('fieldname') == 'name' and self.reference_doctype:
						if permission.get('applicable_for') == self.reference_doctype:
							docs.append(permission.get('doc'))

					elif permission.get('applicable_for') == self.doctype:
						docs.append(permission.get('doc'))

				if docs:
					values = ", ".join(frappe.db.escape(doc, percent=False) for doc in docs)
					condition += f"`tab{self.doctype}`.`{df.get('fieldname')}` in ({values})"
					match_conditions.append(f"({condition})")
					match_filters[df.get('options')] = docs

		if match_conditions:
			self.match_conditions.append(" and ".join(match_conditions))

		if match_filters:
			self.match_filters.append(match_filters)

	def get_permission_query_conditions(self):
		conditions = []
		condition_methods = frappe.get_hooks("permission_query_conditions", {}).get(self.doctype, [])
		if condition_methods:
			for method in condition_methods:
				c = frappe.call(frappe.get_attr(method), self.user)
				if c:
					conditions.append(c)

		permision_script_name = get_server_script_map().get("permission_query", {}).get(self.doctype)
		if permision_script_name:
			script = frappe.get_doc("Server Script", permision_script_name)
			condition = script.get_permission_query_conditions(self.user)
			if condition:
				conditions.append(condition)

		return " and ".join(conditions) if conditions else ""

	def set_order_by(self, args):
		meta = frappe.get_meta(self.doctype)

		if self.order_by and self.order_by != "KEEP_DEFAULT_ORDERING":
			args.order_by = self.order_by
		else:
			args.order_by = ""

			# don't add order by from meta if a mysql group function is used without group by clause
			group_function_without_group_by = (len(self.fields)==1 and
				(	self.fields[0].lower().startswith("count(")
					or self.fields[0].lower().startswith("min(")
					or self.fields[0].lower().startswith("max(")
				) and not self.group_by)

			if not group_function_without_group_by:
				sort_field = sort_order = None
				if meta.sort_field and ',' in meta.sort_field:
					# multiple sort given in doctype definition
					# Example:
					# `idx desc, modified desc`
					# will covert to
					# `tabItem`.`idx` desc, `tabItem`.`modified` desc
					args.order_by = ', '.join(
						f"`tab{self.doctype}`.`{f.split()[0].strip()}` {f.split()[1].strip()}" for f in meta.sort_field.split(',')
					)
				else:
					sort_field = meta.sort_field or 'modified'
					sort_order = (meta.sort_field and meta.sort_order) or 'desc'
					if self.order_by:
						args.order_by = f"`tab{self.doctype}`.`{sort_field or 'modified'}` {sort_order or 'desc'}"

				# draft docs always on top
				if hasattr(meta, 'is_submittable') and meta.is_submittable:
					if self.order_by:
						args.order_by = f"`tab{self.doctype}`.docstatus asc, {args.order_by}"

	def validate_order_by_and_group_by(self, parameters):
		"""Check order by, group by so that atleast one column is selected and does not have subquery"""
		if not parameters:
			return

		_lower = parameters.lower()
		if 'select' in _lower and 'from' in _lower:
			frappe.throw(_('Cannot use sub-query in order by'))

		if re.compile(r".*[^a-z0-9-_ ,`'\"\.\(\)].*").match(_lower):
			frappe.throw(_('Illegal SQL Query'))

		for field in parameters.split(","):
			if "." in field and field.strip().startswith("`tab"):
				tbl = field.strip().split('.')[0]
				if tbl not in self.tables:
					if tbl.startswith('`'):
						tbl = tbl[4:-1]
					frappe.throw(_("Please select atleast 1 column from {0} to sort/group").format(tbl))

	def add_limit(self):
		if self.limit_page_length:
			return 'limit %s offset %s' % (self.limit_page_length, self.limit_start)
		else:
			return ''

	def add_comment_count(self, result):
		for r in result:
			if not r.name:
				continue

			r._comment_count = 0
			if "_comments" in r:
				r._comment_count = len(json.loads(r._comments or "[]"))

	def update_user_settings(self):
		# update user settings if new search
		user_settings = json.loads(get_user_settings(self.doctype))

		if hasattr(self, 'user_settings'):
			user_settings.update(self.user_settings)

		if self.save_user_settings_fields:
			user_settings['fields'] = self.user_settings_fields

		update_user_settings(self.doctype, user_settings)

def check_parent_permission(parent, child_doctype):
	if parent:
		# User may pass fake parent and get the information from the child table
		if child_doctype and not (
			frappe.db.exists('DocField', {'parent': parent, 'options': child_doctype})
			or frappe.db.exists('Custom Field', {'dt': parent, 'options': child_doctype})
		):
			raise frappe.PermissionError

		if frappe.permissions.has_permission(parent):
			return

	# Either parent not passed or the user doesn't have permission on parent doctype of child table!
	raise frappe.PermissionError

def get_order_by(doctype, meta):
	order_by = ""

	sort_field = sort_order = None
	if meta.sort_field and ',' in meta.sort_field:
		# multiple sort given in doctype definition
		# Example:
		# `idx desc, modified desc`
		# will covert to
		# `tabItem`.`idx` desc, `tabItem`.`modified` desc
		order_by = ', '.join(f"`tab{doctype}`.`{f.split()[0].strip()}` {f.split()[1].strip()}" for f in meta.sort_field.split(','))

	else:
		sort_field = meta.sort_field or 'modified'
		sort_order = (meta.sort_field and meta.sort_order) or 'desc'
		order_by = f"`tab{doctype}`.`{sort_field or 'modified'}` {sort_order or 'desc'}"

	# draft docs always on top
	if meta.is_submittable:
		order_by = f"`tab{doctype}`.docstatus asc, {order_by}"

	return order_by

def is_parent_only_filter(doctype, filters):
	#check if filters contains only parent doctype
	only_parent_doctype = True

	if isinstance(filters, list):
		for flt in filters:
			if doctype not in flt:
				only_parent_doctype = False
			if 'Between' in flt:
				flt[3] = get_between_date_filter(flt[3])

	return only_parent_doctype

def has_any_user_permission_for_doctype(doctype, user, applicable_for):
	user_permissions = frappe.permissions.get_user_permissions(user=user)
	doctype_user_permissions = user_permissions.get(doctype, [])

	for permission in doctype_user_permissions:
		if not permission.applicable_for or permission.applicable_for == applicable_for:
			return True

	return False

def get_between_date_filter(value, df=None):
	'''
		return the formattted date as per the given example
		[u'2017-11-01', u'2017-11-03'] => '2017-11-01 00:00:00.000000' AND '2017-11-04 00:00:00.000000'
	'''
	from_date = frappe.utils.nowdate()
	to_date = frappe.utils.nowdate()

	if value and isinstance(value, (list, tuple)):
		if len(value) >= 1: from_date = value[0]
		if len(value) >= 2: to_date = value[1]

	if not df or (df and df.fieldtype == 'Datetime'):
		to_date = add_to_date(to_date, days=1)

	if df and df.fieldtype == 'Datetime':
		data = "'%s' AND '%s'" % (
			frappe.db.format_datetime(from_date),
			frappe.db.format_datetime(to_date))
	else:
		data = "'%s' AND '%s'" % (
			frappe.db.format_date(from_date),
			frappe.db.format_date(to_date))

	return data

def get_additional_filter_field(additional_filters_config, f, value):
	additional_filter = additional_filters_config[f.operator.lower()]
	f = frappe._dict(frappe.get_attr(additional_filter['get_field'])())
	if f.query_value:
		for option in f.options:
			option = frappe._dict(option)
			if option.value == value:
				f.value = option.query_value
	return f

def get_date_range(operator, value):
	timespan_map = {
		'1 week': 'week',
		'1 month': 'month',
		'3 months': 'quarter',
		'6 months': '6 months',
		'1 year': 'year',
	}
	period_map = {
		'previous': 'last',
		'next': 'next',
	}

	timespan = period_map[operator] + ' ' + timespan_map[value] if operator != 'timespan' else value

	return get_timespan_date_range(timespan)

def requires_owner_constraint(role_permissions):
	"""Returns True if "select" or "read" isn't available without being creator."""

	if not role_permissions.get("has_if_owner_enabled"):
		return

	if_owner_perms = role_permissions.get("if_owner")
	if not if_owner_perms:
		return

	# has select or read without if owner, no need for constraint
	for perm_type in ("select", "read"):
		if role_permissions.get(perm_type) and perm_type not in if_owner_perms:
			return

	# not checking if either select or read if present in if_owner_perms
	# because either of those is required to perform a query
	return True