from typing import Any, Dict
from sqlalchemy.ext.compiler import compiles
from sqlalchemy.sql.compiler import SQLCompiler
from sqlalchemy.sql.functions import FunctionElement
from sqlalchemy.types import JSON
[docs]class build_object(FunctionElement): # type: ignore
r"""JSON object creation
:Dialects:
- mysql
- postgresql
- sqlite
:param expression: A SQL expression, such as a
:class:`ColumnElement` expression or a :class:`TextClause` with elements
that are castable as JSON
:return: :class:`FuntionElement`
E.g.::
from sqlalchemy import select
from sqla_ext import func as func_ext
query = select([
func_ext.json.build_object("first_key", "first_value", "second_key", 2)
])
The above statement will produce SQL resembling::
SELECT
jsonb_build_object('first_key', 'first_value', 'second_key', 2)
"""
type = JSON()
name = "jsonb_build_object"
@compiles(build_object, "postgresql")
def pg_build_object(
element: build_object, compiler: SQLCompiler, **kw: Dict[str, Any]
) -> str:
return "jsonb_build_object(%s)" % compiler.process(element.clauses, **kw)
@compiles(build_object, "sqlite")
@compiles(build_object, "mysql")
def other_build_object(
element: build_object, compiler: SQLCompiler, **kw: Dict[str, Any]
) -> str:
return "json_object(%s)" % compiler.process(element.clauses, **kw)