Class JSONArray

django/db/models/functions/json.py:8–65

class JSONArray(Func):
    function = "JSON_ARRAY"
    output_field = JSONField()

    def as_sql(self, compiler, connection, **extra_context):
        if not connection.features.supports_json_field:
            raise NotSupportedError(
                "JSONFields are not supported on this database backend."
            )
        return super().as_sql(compiler, connection, **extra_context)

    def as_native(self, compiler, connection, *, returning, **extra_context):
        # PostgreSQL 16+ and Oracle remove SQL NULL values from the array by
        # default. Adds the NULL ON NULL clause to keep NULL values in the
        # array, mapping them to JSON null values, which matches the behavior
        # of SQLite.
        null_on_null = "NULL ON NULL" if len(self.get_source_expressions()) > 0 else ""

        return self.as_sql(
            compiler,
            connection,
            template=(
                f"%(function)s(%(expressions)s {null_on_null} RETURNING {returning})"
            ),
            **extra_context,
        )

    def as_postgresql(self, compiler, connection, **extra_context):
        # Casting source expressions is only required using JSONB_BUILD_ARRAY
        # or when using JSON_ARRAY on PostgreSQL 16+ with server-side bindings.
        # This is done in all cases for consistency.
        casted_obj = self.copy()
        casted_obj.set_source_expressions(
            [
                (
                    # Conditional Cast to avoid unnecessary wrapping.
                    expression
                    if isinstance(expression, Cast)
                    else Cast(expression, expression.output_field)
                )
                for expression in casted_obj.get_source_expressions()
            ]
        )

        if connection.features.is_postgresql_16:
            return casted_obj.as_native(
                compiler, connection, returning="JSONB", **extra_context
            )

        return casted_obj.as_sql(
            compiler,
            connection,
            function="JSONB_BUILD_ARRAY",
            **extra_context,
        )

    def as_oracle(self, compiler, connection, **extra_context):
        return self.as_native(compiler, connection, returning="CLOB", **extra_context)