Merge pull request #714 from datafold/simplify-collapse-abcs

Squash the redundant abstract classes into their "base" counterparts

Author: nolar

data_diff/abcs/database_types.py

@@ -1,12 +1,10 @@
 import decimal
 from abc import ABC, abstractmethod
-from typing import Sequence, Optional, Tuple, Union, Dict, List
+from typing import Tuple, Union
 from datetime import datetime
 
 from runtype import dataclass
-from typing_extensions import Self
 
-from data_diff.abcs.compiler import AbstractCompiler
 from data_diff.utils import ArithAlphanumeric, ArithUUID, Unknown
 
 
@@ -172,255 +170,3 @@ class UnknownColType(ColType):
     text: str
 
     supported = False
-
-
-class AbstractDialect(ABC):
-    """Dialect-dependent query expressions"""
-
-    @abstractmethod
-    def compile(self, compiler: AbstractCompiler, elem, params=None) -> str:
-        raise NotImplementedError
-
-    @abstractmethod
-    def parse_table_name(self, name: str) -> DbPath:
-        "Parse the given table name into a DbPath"
-
-    @property
-    @abstractmethod
-    def name(self) -> str:
-        "Name of the dialect"
-
-    @classmethod
-    @abstractmethod
-    def load_mixins(cls, *abstract_mixins) -> Self:
-        "Load a list of mixins that implement the given abstract mixins"
-
-    @property
-    @abstractmethod
-    def ROUNDS_ON_PREC_LOSS(self) -> bool:
-        "True if db rounds real values when losing precision, False if it truncates."
-
-    @abstractmethod
-    def quote(self, s: str):
-        "Quote SQL name"
-
-    @abstractmethod
-    def concat(self, items: List[str]) -> str:
-        "Provide SQL for concatenating a bunch of columns into a string"
-
-    @abstractmethod
-    def is_distinct_from(self, a: str, b: str) -> str:
-        "Provide SQL for a comparison where NULL = NULL is true"
-
-    @abstractmethod
-    def to_string(self, s: str) -> str:
-        # TODO rewrite using cast_to(x, str)
-        "Provide SQL for casting a column to string"
-
-    @abstractmethod
-    def random(self) -> str:
-        "Provide SQL for generating a random number betweein 0..1"
-
-    @abstractmethod
-    def current_timestamp(self) -> str:
-        "Provide SQL for returning the current timestamp, aka now"
-
-    @abstractmethod
-    def current_database(self) -> str:
-        "Provide SQL for returning the current default database."
-
-    @abstractmethod
-    def current_schema(self) -> str:
-        "Provide SQL for returning the current default schema."
-
-    @abstractmethod
-    def offset_limit(
-        self, offset: Optional[int] = None, limit: Optional[int] = None, has_order_by: Optional[bool] = None
-    ) -> str:
-        "Provide SQL fragment for limit and offset inside a select"
-
-    @abstractmethod
-    def explain_as_text(self, query: str) -> str:
-        "Provide SQL for explaining a query, returned as table(varchar)"
-
-    @abstractmethod
-    def timestamp_value(self, t: datetime) -> str:
-        "Provide SQL for the given timestamp value"
-
-    @abstractmethod
-    def set_timezone_to_utc(self) -> str:
-        "Provide SQL for setting the session timezone to UTC"
-
-    @abstractmethod
-    def parse_type(
-        self,
-        table_path: DbPath,
-        col_name: str,
-        type_repr: str,
-        datetime_precision: int = None,
-        numeric_precision: int = None,
-        numeric_scale: int = None,
-    ) -> ColType:
-        "Parse type info as returned by the database"
-
-    @abstractmethod
-    def to_comparable(self, value: str, coltype: ColType) -> str:
-        """Ensure that the expression is comparable in ``IS DISTINCT FROM``."""
-
-
-from typing import TypeVar, Generic
-
-T_Dialect = TypeVar("T_Dialect", bound=AbstractDialect)
-
-
-class AbstractDatabase(Generic[T_Dialect]):
-    @property
-    @abstractmethod
-    def dialect(self) -> T_Dialect:
-        "The dialect of the database. Used internally by Database, and also available publicly."
-
-    @classmethod
-    @abstractmethod
-    def load_mixins(cls, *abstract_mixins) -> type:
-        "Extend the dialect with a list of mixins that implement the given abstract mixins."
-
-    @property
-    @abstractmethod
-    def CONNECT_URI_HELP(self) -> str:
-        "Example URI to show the user in help and error messages"
-
-    @property
-    @abstractmethod
-    def CONNECT_URI_PARAMS(self) -> List[str]:
-        "List of parameters given in the path of the URI"
-
-    @abstractmethod
-    def _query(self, sql_code: str) -> list:
-        "Send query to database and return result"
-
-    @abstractmethod
-    def query_table_schema(self, path: DbPath) -> Dict[str, tuple]:
-        """Query the table for its schema for table in 'path', and return {column: tuple}
-        where the tuple is (table_name, col_name, type_repr, datetime_precision?, numeric_precision?, numeric_scale?)
-
-        Note: This method exists instead of select_table_schema(), just because not all databases support
-              accessing the schema using a SQL query.
-        """
-
-    @abstractmethod
-    def select_table_unique_columns(self, path: DbPath) -> str:
-        "Provide SQL for selecting the names of unique columns in the table"
-
-    @abstractmethod
-    def query_table_unique_columns(self, path: DbPath) -> List[str]:
-        """Query the table for its unique columns for table in 'path', and return {column}"""
-
-    @abstractmethod
-    def _process_table_schema(
-        self, path: DbPath, raw_schema: Dict[str, tuple], filter_columns: Sequence[str], where: str = None
-    ):
-        """Process the result of query_table_schema().
-
-        Done in a separate step, to minimize the amount of processed columns.
-        Needed because processing each column may:
-        * throw errors and warnings
-        * query the database to sample values
-
-        """
-
-    @abstractmethod
-    def close(self):
-        "Close connection(s) to the database instance. Querying will stop functioning."
-
-    @property
-    @abstractmethod
-    def is_autocommit(self) -> bool:
-        "Return whether the database autocommits changes. When false, COMMIT statements are skipped."
-
-
-class AbstractTable(ABC):
-    @abstractmethod
-    def select(self, *exprs, distinct=False, **named_exprs) -> "AbstractTable":
-        """Choose new columns, based on the old ones. (aka Projection)
-
-        Parameters:
-            exprs: List of expressions to constitute the columns of the new table.
-                    If not provided, returns all columns in source table (i.e. ``select *``)
-            distinct: 'select' or 'select distinct'
-            named_exprs: More expressions to constitute the columns of the new table, aliased to keyword name.
-
-        """
-        # XXX distinct=SKIP
-
-    @abstractmethod
-    def where(self, *exprs) -> "AbstractTable":
-        """Filter the rows, based on the given predicates. (aka Selection)"""
-
-    @abstractmethod
-    def order_by(self, *exprs) -> "AbstractTable":
-        """Order the rows lexicographically, according to the given expressions."""
-
-    @abstractmethod
-    def limit(self, limit: int) -> "AbstractTable":
-        """Stop yielding rows after the given limit. i.e. take the first 'n=limit' rows"""
-
-    @abstractmethod
-    def join(self, target) -> "AbstractTable":
-        """Join the current table with the target table, returning a new table containing both side-by-side.
-
-        When joining, it's recommended to use explicit tables names, instead of `this`, in order to avoid potential name collisions.
-
-        Example:
-            ::
-
-                person = table('person')
-                city = table('city')
-
-                name_and_city = (
-                    person
-                    .join(city)
-                    .on(person['city_id'] == city['id'])
-                    .select(person['id'], city['name'])
-                )
-        """
-
-    @abstractmethod
-    def group_by(self, *keys):
-        """Behaves like in SQL, except for a small change in syntax:
-
-        A call to `.agg()` must follow every call to `.group_by()`.
-
-        Example:
-            ::
-
-                # SELECT a, sum(b) FROM tmp GROUP BY 1
-                table('tmp').group_by(this.a).agg(this.b.sum())
-
-                # SELECT a, sum(b) FROM a GROUP BY 1 HAVING (b > 10)
-                (table('tmp')
-                    .group_by(this.a)
-                    .agg(this.b.sum())
-                    .having(this.b > 10)
-                )
-
-        """
-
-    @abstractmethod
-    def count(self) -> int:
-        """SELECT count() FROM self"""
-
-    @abstractmethod
-    def union(self, other: "ITable"):
-        """SELECT * FROM self UNION other"""
-
-    @abstractmethod
-    def union_all(self, other: "ITable"):
-        """SELECT * FROM self UNION ALL other"""
-
-    @abstractmethod
-    def minus(self, other: "ITable"):
-        """SELECT * FROM self EXCEPT other"""
-
-    @abstractmethod
-    def intersect(self, other: "ITable"):
-        """SELECT * FROM self INTERSECT other"""

data_diff/abcs/mixins.py

@@ -134,12 +134,6 @@ def list_tables(self, table_schema: str, like: Compilable = None) -> Compilable:
         """
 
 
-class AbstractMixin_Regex(AbstractMixin):
-    @abstractmethod
-    def test_regex(self, string: Compilable, pattern: Compilable) -> Compilable:
-        """Tests whether the regex pattern matches the string. Returns a bool expression."""
-
-
 class AbstractMixin_RandomSample(AbstractMixin):
     @abstractmethod
     def random_sample_n(self, tbl: str, size: int) -> str:
@@ -152,7 +146,7 @@ def random_sample_ratio_approx(self, tbl: str, ratio: float) -> str:
         i.e. the actual mount of rows returned may vary by standard deviation.
         """
 
-    # def random_sample_ratio(self, table: AbstractTable, ratio: float):
+    # def random_sample_ratio(self, table: ITable, ratio: float):
     #     """Take a random sample of the size determined by the ratio (0..1), where 0 means no rows, and 1 means all rows
     #     """