remove sample_row_in_table_info and simplify set operations in SQLDB (#932)

-Address TODO: deprecate for sample_row_in_table_info
-Simplify set operations by casting to sets to not need multiple set
casts + .difference() calls

langchain/sql_database.py

@@ -17,40 +17,30 @@ class SQLDatabase:
         ignore_tables: Optional[List[str]] = None,
         include_tables: Optional[List[str]] = None,
         sample_rows_in_table_info: int = 0,
-        # TODO: deprecate.
-        sample_row_in_table_info: bool = False,
     ):
         """Create engine from database URI."""
-        if sample_row_in_table_info and sample_rows_in_table_info > 0:
-            raise ValueError(
-                "Only one of `sample_row_in_table_info` "
-                "and `sample_rows_in_table_info` should be set"
-            )
         self._engine = engine
         self._schema = schema
         if include_tables and ignore_tables:
             raise ValueError("Cannot specify both include_tables and ignore_tables")
 
         self._inspector = inspect(self._engine)
-        self._all_tables = self._inspector.get_table_names(schema=schema)
-        self._include_tables = include_tables or []
+        self._all_tables = set(self._inspector.get_table_names(schema=schema))
+        self._include_tables = set(include_tables) if include_tables else set()
         if self._include_tables:
-            missing_tables = set(self._include_tables).difference(self._all_tables)
+            missing_tables = self._include_tables - self._all_tables
             if missing_tables:
                 raise ValueError(
                     f"include_tables {missing_tables} not found in database"
                 )
-        self._ignore_tables = ignore_tables or []
+        self._ignore_tables = set(ignore_tables) if ignore_tables else set()
         if self._ignore_tables:
-            missing_tables = set(self._ignore_tables).difference(self._all_tables)
+            missing_tables = self._ignore_tables - self._all_tables
             if missing_tables:
                 raise ValueError(
                     f"ignore_tables {missing_tables} not found in database"
                 )
         self._sample_rows_in_table_info = sample_rows_in_table_info
-        # TODO: deprecate
-        if sample_row_in_table_info:
-            self._sample_rows_in_table_info = 1
 
     @classmethod
     def from_uri(cls, database_uri: str, **kwargs: Any) -> SQLDatabase:
@@ -66,7 +56,7 @@ class SQLDatabase:
         """Get names of tables available."""
         if self._include_tables:
             return self._include_tables
-        return set(self._all_tables) - set(self._ignore_tables)
+        return self._all_tables - self._ignore_tables
 
     @property
     def table_info(self) -> str: