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Diffstat (limited to 'libs/sqlalchemy/dialects/postgresql/array.py')
| -rw-r--r-- | libs/sqlalchemy/dialects/postgresql/array.py | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/libs/sqlalchemy/dialects/postgresql/array.py b/libs/sqlalchemy/dialects/postgresql/array.py new file mode 100644 index 000000000..5b53916c6 --- /dev/null +++ b/libs/sqlalchemy/dialects/postgresql/array.py @@ -0,0 +1,439 @@ +# postgresql/array.py +# Copyright (C) 2005-2023 the SQLAlchemy authors and contributors +# <see AUTHORS file> +# +# This module is part of SQLAlchemy and is released under +# the MIT License: https://www.opensource.org/licenses/mit-license.php +# mypy: ignore-errors + + +from __future__ import annotations + +import re +from typing import Any +from typing import Optional +from typing import TypeVar + +from ... import types as sqltypes +from ... import util +from ...sql import expression +from ...sql import operators +from ...sql._typing import _TypeEngineArgument + + +_T = TypeVar("_T", bound=Any) + + +def Any(other, arrexpr, operator=operators.eq): + """A synonym for the ARRAY-level :meth:`.ARRAY.Comparator.any` method. + See that method for details. + + """ + + return arrexpr.any(other, operator) + + +def All(other, arrexpr, operator=operators.eq): + """A synonym for the ARRAY-level :meth:`.ARRAY.Comparator.all` method. + See that method for details. + + """ + + return arrexpr.all(other, operator) + + +class array(expression.ExpressionClauseList[_T]): + + """A PostgreSQL ARRAY literal. + + This is used to produce ARRAY literals in SQL expressions, e.g.:: + + from sqlalchemy.dialects.postgresql import array + from sqlalchemy.dialects import postgresql + from sqlalchemy import select, func + + stmt = select(array([1,2]) + array([3,4,5])) + + print(stmt.compile(dialect=postgresql.dialect())) + + Produces the SQL:: + + SELECT ARRAY[%(param_1)s, %(param_2)s] || + ARRAY[%(param_3)s, %(param_4)s, %(param_5)s]) AS anon_1 + + An instance of :class:`.array` will always have the datatype + :class:`_types.ARRAY`. The "inner" type of the array is inferred from + the values present, unless the ``type_`` keyword argument is passed:: + + array(['foo', 'bar'], type_=CHAR) + + Multidimensional arrays are produced by nesting :class:`.array` constructs. + The dimensionality of the final :class:`_types.ARRAY` + type is calculated by + recursively adding the dimensions of the inner :class:`_types.ARRAY` + type:: + + stmt = select( + array([ + array([1, 2]), array([3, 4]), array([column('q'), column('x')]) + ]) + ) + print(stmt.compile(dialect=postgresql.dialect())) + + Produces:: + + SELECT ARRAY[ARRAY[%(param_1)s, %(param_2)s], + ARRAY[%(param_3)s, %(param_4)s], ARRAY[q, x]] AS anon_1 + + .. versionadded:: 1.3.6 added support for multidimensional array literals + + .. seealso:: + + :class:`_postgresql.ARRAY` + + """ + + __visit_name__ = "array" + + stringify_dialect = "postgresql" + inherit_cache = True + + def __init__(self, clauses, **kw): + + type_arg = kw.pop("type_", None) + super().__init__(operators.comma_op, *clauses, **kw) + + self._type_tuple = [arg.type for arg in self.clauses] + + main_type = ( + type_arg + if type_arg is not None + else self._type_tuple[0] + if self._type_tuple + else sqltypes.NULLTYPE + ) + + if isinstance(main_type, ARRAY): + self.type = ARRAY( + main_type.item_type, + dimensions=main_type.dimensions + 1 + if main_type.dimensions is not None + else 2, + ) + else: + self.type = ARRAY(main_type) + + @property + def _select_iterable(self): + return (self,) + + def _bind_param(self, operator, obj, _assume_scalar=False, type_=None): + if _assume_scalar or operator is operators.getitem: + return expression.BindParameter( + None, + obj, + _compared_to_operator=operator, + type_=type_, + _compared_to_type=self.type, + unique=True, + ) + + else: + return array( + [ + self._bind_param( + operator, o, _assume_scalar=True, type_=type_ + ) + for o in obj + ] + ) + + def self_group(self, against=None): + if against in (operators.any_op, operators.all_op, operators.getitem): + return expression.Grouping(self) + else: + return self + + +CONTAINS = operators.custom_op("@>", precedence=5, is_comparison=True) + +CONTAINED_BY = operators.custom_op("<@", precedence=5, is_comparison=True) + +OVERLAP = operators.custom_op("&&", precedence=5, is_comparison=True) + + +class ARRAY(sqltypes.ARRAY): + + """PostgreSQL ARRAY type. + + .. versionchanged:: 1.1 The :class:`_postgresql.ARRAY` type is now + a subclass of the core :class:`_types.ARRAY` type. + + The :class:`_postgresql.ARRAY` type is constructed in the same way + as the core :class:`_types.ARRAY` type; a member type is required, and a + number of dimensions is recommended if the type is to be used for more + than one dimension:: + + from sqlalchemy.dialects import postgresql + + mytable = Table("mytable", metadata, + Column("data", postgresql.ARRAY(Integer, dimensions=2)) + ) + + The :class:`_postgresql.ARRAY` type provides all operations defined on the + core :class:`_types.ARRAY` type, including support for "dimensions", + indexed access, and simple matching such as + :meth:`.types.ARRAY.Comparator.any` and + :meth:`.types.ARRAY.Comparator.all`. :class:`_postgresql.ARRAY` + class also + provides PostgreSQL-specific methods for containment operations, including + :meth:`.postgresql.ARRAY.Comparator.contains` + :meth:`.postgresql.ARRAY.Comparator.contained_by`, and + :meth:`.postgresql.ARRAY.Comparator.overlap`, e.g.:: + + mytable.c.data.contains([1, 2]) + + The :class:`_postgresql.ARRAY` type may not be supported on all + PostgreSQL DBAPIs; it is currently known to work on psycopg2 only. + + Additionally, the :class:`_postgresql.ARRAY` + type does not work directly in + conjunction with the :class:`.ENUM` type. For a workaround, see the + special type at :ref:`postgresql_array_of_enum`. + + .. container:: topic + + **Detecting Changes in ARRAY columns when using the ORM** + + The :class:`_postgresql.ARRAY` type, when used with the SQLAlchemy ORM, + does not detect in-place mutations to the array. In order to detect + these, the :mod:`sqlalchemy.ext.mutable` extension must be used, using + the :class:`.MutableList` class:: + + from sqlalchemy.dialects.postgresql import ARRAY + from sqlalchemy.ext.mutable import MutableList + + class SomeOrmClass(Base): + # ... + + data = Column(MutableList.as_mutable(ARRAY(Integer))) + + This extension will allow "in-place" changes such to the array + such as ``.append()`` to produce events which will be detected by the + unit of work. Note that changes to elements **inside** the array, + including subarrays that are mutated in place, are **not** detected. + + Alternatively, assigning a new array value to an ORM element that + replaces the old one will always trigger a change event. + + .. seealso:: + + :class:`_types.ARRAY` - base array type + + :class:`_postgresql.array` - produces a literal array value. + + """ + + class Comparator(sqltypes.ARRAY.Comparator): + + """Define comparison operations for :class:`_types.ARRAY`. + + Note that these operations are in addition to those provided + by the base :class:`.types.ARRAY.Comparator` class, including + :meth:`.types.ARRAY.Comparator.any` and + :meth:`.types.ARRAY.Comparator.all`. + + """ + + def contains(self, other, **kwargs): + """Boolean expression. Test if elements are a superset of the + elements of the argument array expression. + + kwargs may be ignored by this operator but are required for API + conformance. + """ + return self.operate(CONTAINS, other, result_type=sqltypes.Boolean) + + def contained_by(self, other): + """Boolean expression. Test if elements are a proper subset of the + elements of the argument array expression. + """ + return self.operate( + CONTAINED_BY, other, result_type=sqltypes.Boolean + ) + + def overlap(self, other): + """Boolean expression. Test if array has elements in common with + an argument array expression. + """ + return self.operate(OVERLAP, other, result_type=sqltypes.Boolean) + + comparator_factory = Comparator + + def __init__( + self, + item_type: _TypeEngineArgument[Any], + as_tuple: bool = False, + dimensions: Optional[int] = None, + zero_indexes: bool = False, + ): + """Construct an ARRAY. + + E.g.:: + + Column('myarray', ARRAY(Integer)) + + Arguments are: + + :param item_type: The data type of items of this array. Note that + dimensionality is irrelevant here, so multi-dimensional arrays like + ``INTEGER[][]``, are constructed as ``ARRAY(Integer)``, not as + ``ARRAY(ARRAY(Integer))`` or such. + + :param as_tuple=False: Specify whether return results + should be converted to tuples from lists. DBAPIs such + as psycopg2 return lists by default. When tuples are + returned, the results are hashable. + + :param dimensions: if non-None, the ARRAY will assume a fixed + number of dimensions. This will cause the DDL emitted for this + ARRAY to include the exact number of bracket clauses ``[]``, + and will also optimize the performance of the type overall. + Note that PG arrays are always implicitly "non-dimensioned", + meaning they can store any number of dimensions no matter how + they were declared. + + :param zero_indexes=False: when True, index values will be converted + between Python zero-based and PostgreSQL one-based indexes, e.g. + a value of one will be added to all index values before passing + to the database. + + .. versionadded:: 0.9.5 + + + """ + if isinstance(item_type, ARRAY): + raise ValueError( + "Do not nest ARRAY types; ARRAY(basetype) " + "handles multi-dimensional arrays of basetype" + ) + if isinstance(item_type, type): + item_type = item_type() + self.item_type = item_type + self.as_tuple = as_tuple + self.dimensions = dimensions + self.zero_indexes = zero_indexes + + @property + def hashable(self): + return self.as_tuple + + @property + def python_type(self): + return list + + def compare_values(self, x, y): + return x == y + + @util.memoized_property + def _against_native_enum(self): + return ( + isinstance(self.item_type, sqltypes.Enum) + and self.item_type.native_enum + ) + + def literal_processor(self, dialect): + item_proc = self.item_type.dialect_impl(dialect).literal_processor( + dialect + ) + if item_proc is None: + return None + + def to_str(elements): + return f"ARRAY[{', '.join(elements)}]" + + def process(value): + inner = self._apply_item_processor( + value, item_proc, self.dimensions, to_str + ) + return inner + + return process + + def bind_processor(self, dialect): + item_proc = self.item_type.dialect_impl(dialect).bind_processor( + dialect + ) + + def process(value): + if value is None: + return value + else: + return self._apply_item_processor( + value, item_proc, self.dimensions, list + ) + + return process + + def result_processor(self, dialect, coltype): + item_proc = self.item_type.dialect_impl(dialect).result_processor( + dialect, coltype + ) + + def process(value): + if value is None: + return value + else: + return self._apply_item_processor( + value, + item_proc, + self.dimensions, + tuple if self.as_tuple else list, + ) + + if self._against_native_enum: + super_rp = process + pattern = re.compile(r"^{(.*)}$") + + def handle_raw_string(value): + inner = pattern.match(value).group(1) + return _split_enum_values(inner) + + def process(value): + if value is None: + return value + # isinstance(value, str) is required to handle + # the case where a TypeDecorator for and Array of Enum is + # used like was required in sa < 1.3.17 + return super_rp( + handle_raw_string(value) + if isinstance(value, str) + else value + ) + + return process + + +def _split_enum_values(array_string): + + if '"' not in array_string: + # no escape char is present so it can just split on the comma + return array_string.split(",") if array_string else [] + + # handles quoted strings from: + # r'abc,"quoted","also\\\\quoted", "quoted, comma", "esc \" quot", qpr' + # returns + # ['abc', 'quoted', 'also\\quoted', 'quoted, comma', 'esc " quot', 'qpr'] + text = array_string.replace(r"\"", "_$ESC_QUOTE$_") + text = text.replace(r"\\", "\\") + result = [] + on_quotes = re.split(r'(")', text) + in_quotes = False + for tok in on_quotes: + if tok == '"': + in_quotes = not in_quotes + elif in_quotes: + result.append(tok.replace("_$ESC_QUOTE$_", '"')) + else: + result.extend(re.findall(r"([^\s,]+),?", tok)) + return result |