GH - 624: Added dtype arg to read_sql

pandas-stubs/io/sql.pyi

@@ -84,6 +84,7 @@ def read_sql(
     columns: list[str] = ...,
     *,
     chunksize: int,
+    dtype: DtypeArg | None = ...,
 ) -> Generator[DataFrame, None, None]: ...
 @overload
 def read_sql(
@@ -95,6 +96,7 @@ def read_sql(
     parse_dates: list[str] | dict[str, str] | dict[str, dict[str, Any]] | None = ...,
     columns: list[str] = ...,
     chunksize: None = ...,
+    dtype: DtypeArg | None = ...,
 ) -> DataFrame: ...
 
 class PandasSQL(PandasObject):

tests/test_io.py

@@ -1204,3 +1204,25 @@ def test_sqlalchemy_text() -> None:
                 assert_type(read_sql(sql_select, con=conn), DataFrame),
                 DataFrame,
             )
+
+
+def test_read_sql_dtype() -> None:
+    with ensure_clean() as path:
+        conn = sqlite3.connect(path)
+        df = pd.DataFrame(
+            data=[[0, "10/11/12"], [1, "12/11/10"]],
+            columns=["int_column", "date_column"],
+        )
+        check(assert_type(df.to_sql("test_data", con=conn), Union[int, None]), int)
+        check(
+            assert_type(
+                pd.read_sql(
+                    "SELECT int_column, date_column FROM test_data",
+                    con=conn,
+                    dtype=None,
+                ),
+                pd.DataFrame,
+            ),
+            pd.DataFrame,
+        )
+        conn.close()