276 lines
11 KiB
Python
276 lines
11 KiB
Python
# Part of Odoo. See LICENSE file for full copyright and licensing details.
|
|
import itertools
|
|
from collections.abc import Iterable, Iterator
|
|
|
|
from .sql import SQL, make_identifier
|
|
|
|
|
|
def _sql_from_table(alias: str, table: SQL) -> SQL:
|
|
""" Return a FROM clause element from ``alias`` and ``table``. """
|
|
if (alias_identifier := SQL.identifier(alias)) == table:
|
|
return table
|
|
return SQL("%s AS %s", table, alias_identifier)
|
|
|
|
|
|
def _sql_from_join(kind: SQL, alias: str, table: SQL, condition: SQL) -> SQL:
|
|
""" Return a FROM clause element for a JOIN. """
|
|
return SQL("%s %s ON (%s)", kind, _sql_from_table(alias, table), condition)
|
|
|
|
|
|
_SQL_JOINS = {
|
|
"JOIN": SQL("JOIN"),
|
|
"LEFT JOIN": SQL("LEFT JOIN"),
|
|
}
|
|
|
|
|
|
def _generate_table_alias(src_table_alias: str, link: str) -> str:
|
|
""" Generate a standard table alias name. An alias is generated as following:
|
|
|
|
- the base is the source table name (that can already be an alias)
|
|
- then, the joined table is added in the alias using a 'link field name'
|
|
that is used to render unique aliases for a given path
|
|
- the name is shortcut if it goes beyond PostgreSQL's identifier limits
|
|
|
|
.. code-block:: pycon
|
|
|
|
>>> _generate_table_alias('res_users', link='parent_id')
|
|
'res_users__parent_id'
|
|
|
|
:param str src_table_alias: alias of the source table
|
|
:param str link: field name
|
|
:return str: alias
|
|
"""
|
|
return make_identifier(f"{src_table_alias}__{link}")
|
|
|
|
|
|
class Query:
|
|
""" Simple implementation of a query object, managing tables with aliases,
|
|
join clauses (with aliases, condition and parameters), where clauses (with
|
|
parameters), order, limit and offset.
|
|
|
|
:param env: model environment (for lazy evaluation)
|
|
:param alias: name or alias of the table
|
|
:param table: a table expression (``str`` or ``SQL`` object), optional
|
|
"""
|
|
|
|
def __init__(self, env, alias: str, table: (SQL | None) = None):
|
|
# database cursor
|
|
self._env = env
|
|
|
|
self._tables: dict[str, SQL] = {
|
|
alias: table if table is not None else SQL.identifier(alias),
|
|
}
|
|
|
|
# joins {alias: (kind(SQL), table(SQL), condition(SQL))}
|
|
self._joins: dict[str, tuple[SQL, SQL, SQL]] = {}
|
|
|
|
# holds the list of WHERE conditions (to be joined with 'AND')
|
|
self._where_clauses: list[SQL] = []
|
|
|
|
# groupby, having, order, limit, offset
|
|
self.groupby: SQL | None = None
|
|
self.having: SQL | None = None
|
|
self._order: SQL | None = None
|
|
self.limit: int | None = None
|
|
self.offset: int | None = None
|
|
|
|
# memoized result
|
|
self._ids: tuple[int, ...] | None = None
|
|
|
|
@staticmethod
|
|
def make_alias(alias: str, link: str) -> str:
|
|
""" Return an alias based on ``alias`` and ``link``. """
|
|
return _generate_table_alias(alias, link)
|
|
|
|
def add_table(self, alias: str, table: (SQL | None) = None):
|
|
""" Add a table with a given alias to the from clause. """
|
|
assert alias not in self._tables and alias not in self._joins, f"Alias {alias!r} already in {self}"
|
|
self._tables[alias] = table if table is not None else SQL.identifier(alias)
|
|
self._ids = None
|
|
|
|
def add_join(self, kind: str, alias: str, table: str | SQL | None, condition: SQL):
|
|
""" Add a join clause with the given alias, table and condition. """
|
|
sql_kind = _SQL_JOINS.get(kind.upper())
|
|
assert sql_kind is not None, f"Invalid JOIN type {kind!r}"
|
|
assert alias not in self._tables, f"Alias {alias!r} already used"
|
|
table = table or alias
|
|
if isinstance(table, str):
|
|
table = SQL.identifier(table)
|
|
|
|
if alias in self._joins:
|
|
assert self._joins[alias] == (sql_kind, table, condition)
|
|
else:
|
|
self._joins[alias] = (sql_kind, table, condition)
|
|
self._ids = None
|
|
|
|
def add_where(self, where_clause: str | SQL, where_params=()):
|
|
""" Add a condition to the where clause. """
|
|
self._where_clauses.append(SQL(where_clause, *where_params)) # pylint: disable = sql-injection
|
|
self._ids = None
|
|
|
|
def join(self, lhs_alias: str, lhs_column: str, rhs_table: str | SQL, rhs_column: str, link: str) -> str:
|
|
"""
|
|
Perform a join between a table already present in the current Query object and
|
|
another table. This method is essentially a shortcut for methods :meth:`~.make_alias`
|
|
and :meth:`~.add_join`.
|
|
|
|
:param str lhs_alias: alias of a table already defined in the current Query object.
|
|
:param str lhs_column: column of `lhs_alias` to be used for the join's ON condition.
|
|
:param str rhs_table: name of the table to join to `lhs_alias`.
|
|
:param str rhs_column: column of `rhs_alias` to be used for the join's ON condition.
|
|
:param str link: used to generate the alias for the joined table, this string should
|
|
represent the relationship (the link) between both tables.
|
|
"""
|
|
assert lhs_alias in self._tables or lhs_alias in self._joins, "Alias %r not in %s" % (lhs_alias, str(self))
|
|
rhs_alias = self.make_alias(lhs_alias, link)
|
|
condition = SQL("%s = %s", SQL.identifier(lhs_alias, lhs_column), SQL.identifier(rhs_alias, rhs_column))
|
|
self.add_join('JOIN', rhs_alias, rhs_table, condition)
|
|
return rhs_alias
|
|
|
|
def left_join(self, lhs_alias: str, lhs_column: str, rhs_table: str, rhs_column: str, link: str) -> str:
|
|
""" Add a LEFT JOIN to the current table (if necessary), and return the
|
|
alias corresponding to ``rhs_table``.
|
|
|
|
See the documentation of :meth:`join` for a better overview of the
|
|
arguments and what they do.
|
|
"""
|
|
assert lhs_alias in self._tables or lhs_alias in self._joins, "Alias %r not in %s" % (lhs_alias, str(self))
|
|
rhs_alias = self.make_alias(lhs_alias, link)
|
|
condition = SQL("%s = %s", SQL.identifier(lhs_alias, lhs_column), SQL.identifier(rhs_alias, rhs_column))
|
|
self.add_join('LEFT JOIN', rhs_alias, rhs_table, condition)
|
|
return rhs_alias
|
|
|
|
@property
|
|
def order(self) -> SQL | None:
|
|
return self._order
|
|
|
|
@order.setter
|
|
def order(self, value: SQL | str | None):
|
|
self._order = SQL(value) if value is not None else None # pylint: disable = sql-injection
|
|
|
|
@property
|
|
def table(self) -> str:
|
|
""" Return the query's main table, i.e., the first one in the FROM clause. """
|
|
return next(iter(self._tables))
|
|
|
|
@property
|
|
def from_clause(self) -> SQL:
|
|
""" Return the FROM clause of ``self``, without the FROM keyword. """
|
|
tables = SQL(", ").join(itertools.starmap(_sql_from_table, self._tables.items()))
|
|
if not self._joins:
|
|
return tables
|
|
items = (
|
|
tables,
|
|
*(
|
|
_sql_from_join(kind, alias, table, condition)
|
|
for alias, (kind, table, condition) in self._joins.items()
|
|
),
|
|
)
|
|
return SQL(" ").join(items)
|
|
|
|
@property
|
|
def where_clause(self) -> SQL:
|
|
""" Return the WHERE condition of ``self``, without the WHERE keyword. """
|
|
return SQL(" AND ").join(self._where_clauses)
|
|
|
|
def is_empty(self) -> bool:
|
|
""" Return whether the query is known to return nothing. """
|
|
return self._ids == ()
|
|
|
|
def select(self, *args: str | SQL) -> SQL:
|
|
""" Return the SELECT query as an ``SQL`` object. """
|
|
sql_args = map(SQL, args) if args else [SQL.identifier(self.table, 'id')]
|
|
return SQL(
|
|
"%s%s%s%s%s%s%s%s",
|
|
SQL("SELECT %s", SQL(", ").join(sql_args)),
|
|
SQL(" FROM %s", self.from_clause),
|
|
SQL(" WHERE %s", self.where_clause) if self._where_clauses else SQL(),
|
|
SQL(" GROUP BY %s", self.groupby) if self.groupby else SQL(),
|
|
SQL(" HAVING %s", self.having) if self.having else SQL(),
|
|
SQL(" ORDER BY %s", self._order) if self._order else SQL(),
|
|
SQL(" LIMIT %s", self.limit) if self.limit else SQL(),
|
|
SQL(" OFFSET %s", self.offset) if self.offset else SQL(),
|
|
)
|
|
|
|
def subselect(self, *args: str | SQL) -> SQL:
|
|
""" Similar to :meth:`.select`, but for sub-queries.
|
|
This one avoids the ORDER BY clause when possible,
|
|
and includes parentheses around the subquery.
|
|
"""
|
|
if self._ids is not None and not args:
|
|
# inject the known result instead of the subquery
|
|
if not self._ids:
|
|
# in case we have nothing, we want to use a sub_query with no records
|
|
# because an empty tuple leads to a syntax error
|
|
# and a tuple containing just None creates issues for `NOT IN`
|
|
return SQL("(SELECT 1 WHERE FALSE)")
|
|
return SQL("%s", self._ids)
|
|
|
|
if self.limit or self.offset:
|
|
# in this case, the ORDER BY clause is necessary
|
|
return SQL("(%s)", self.select(*args))
|
|
|
|
sql_args = map(SQL, args) if args else [SQL.identifier(self.table, 'id')]
|
|
return SQL(
|
|
"(%s%s%s)",
|
|
SQL("SELECT %s", SQL(", ").join(sql_args)),
|
|
SQL(" FROM %s", self.from_clause),
|
|
SQL(" WHERE %s", self.where_clause) if self._where_clauses else SQL(),
|
|
)
|
|
|
|
def get_result_ids(self) -> tuple[int, ...]:
|
|
""" Return the result of ``self.select()`` as a tuple of ids. The result
|
|
is memoized for future use, which avoids making the same query twice.
|
|
"""
|
|
if self._ids is None:
|
|
self._ids = tuple(id_ for id_, in self._env.execute_query(self.select()))
|
|
return self._ids
|
|
|
|
def set_result_ids(self, ids: Iterable[int], ordered: bool = True) -> None:
|
|
""" Set up the query to return the lines given by ``ids``. The parameter
|
|
``ordered`` tells whether the query must be ordered to match exactly the
|
|
sequence ``ids``.
|
|
"""
|
|
assert not (self._joins or self._where_clauses or self.limit or self.offset), \
|
|
"Method set_result_ids() can only be called on a virgin Query"
|
|
ids = tuple(ids)
|
|
if not ids:
|
|
self.add_where("FALSE")
|
|
elif ordered:
|
|
# This guarantees that self.select() returns the results in the
|
|
# expected order of ids:
|
|
# SELECT "stuff".id
|
|
# FROM "stuff"
|
|
# JOIN (SELECT * FROM unnest(%s) WITH ORDINALITY) AS "stuff__ids"
|
|
# ON ("stuff"."id" = "stuff__ids"."unnest")
|
|
# ORDER BY "stuff__ids"."ordinality"
|
|
alias = self.join(
|
|
self.table, 'id',
|
|
SQL('(SELECT * FROM unnest(%s) WITH ORDINALITY)', list(ids)), 'unnest',
|
|
'ids',
|
|
)
|
|
self.order = SQL.identifier(alias, 'ordinality')
|
|
else:
|
|
self.add_where(SQL("%s IN %s", SQL.identifier(self.table, 'id'), ids))
|
|
self._ids = ids
|
|
|
|
def __str__(self) -> str:
|
|
sql = self.select()
|
|
return f"<Query: {sql.code!r} with params: {sql.params!r}>"
|
|
|
|
def __bool__(self):
|
|
return bool(self.get_result_ids())
|
|
|
|
def __len__(self) -> int:
|
|
if self._ids is None:
|
|
if self.limit or self.offset:
|
|
# optimization: generate a SELECT FROM, and then count the rows
|
|
sql = SQL("SELECT COUNT(*) FROM (%s) t", self.select(""))
|
|
else:
|
|
sql = self.select('COUNT(*)')
|
|
return self._env.execute_query(sql)[0][0]
|
|
return len(self.get_result_ids())
|
|
|
|
def __iter__(self) -> Iterator[int]:
|
|
return iter(self.get_result_ids())
|