diff --git a/src/accounting/account/views.py b/src/accounting/account/views.py
index 20259bc..6fae6ac 100644
--- a/src/accounting/account/views.py
+++ b/src/accounting/account/views.py
@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Account, BaseAccount
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
@@ -86,7 +87,7 @@ def add_account() -> redirect:
     form.populate_obj(account)
     db.session.add(account)
     db.session.commit()
-    flash(lazy_gettext("The account is added successfully"), "success")
+    flash(s(lazy_gettext("The account is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(account)))
 
 
@@ -138,12 +139,12 @@ def update_account(account: Account) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(account)
     if not account.is_modified:
-        flash(lazy_gettext("The account was not modified."), "success")
+        flash(s(lazy_gettext("The account was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(account)))
     account.updated_by_id = get_current_user_pk()
     account.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The account is updated successfully."), "success")
+    flash(s(lazy_gettext("The account is updated successfully.")), "success")
     return redirect(inherit_next(__get_detail_uri(account)))
 
 
@@ -159,7 +160,7 @@ def delete_account(account: Account) -> redirect:
     account.delete()
     sort_accounts_in(account.base_code, account.id)
     db.session.commit()
-    flash(lazy_gettext("The account is deleted successfully."), "success")
+    flash(s(lazy_gettext("The account is deleted successfully.")), "success")
     return redirect(or_next(__get_list_uri()))
 
 
@@ -186,10 +187,10 @@ def sort_accounts(base: BaseAccount) -> redirect:
     form: AccountReorderForm = AccountReorderForm(base)
     form.save_order()
     if not form.is_modified:
-        flash(lazy_gettext("The order was not modified."), "success")
+        flash(s(lazy_gettext("The order was not modified.")), "success")
         return redirect(or_next(__get_list_uri()))
     db.session.commit()
-    flash(lazy_gettext("The order is updated successfully."), "success")
+    flash(s(lazy_gettext("The order is updated successfully.")), "success")
     return redirect(or_next(__get_list_uri()))
 
 
diff --git a/src/accounting/currency/views.py b/src/accounting/currency/views.py
index 2dba542..1983f04 100644
--- a/src/accounting/currency/views.py
+++ b/src/accounting/currency/views.py
@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Currency
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
@@ -88,7 +89,7 @@ def add_currency() -> redirect:
     form.populate_obj(currency)
     db.session.add(currency)
     db.session.commit()
-    flash(lazy_gettext("The currency is added successfully"), "success")
+    flash(s(lazy_gettext("The currency is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(currency)))
 
 
@@ -141,12 +142,12 @@ def update_currency(currency: Currency) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(currency)
     if not currency.is_modified:
-        flash(lazy_gettext("The currency was not modified."), "success")
+        flash(s(lazy_gettext("The currency was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(currency)))
     currency.updated_by_id = get_current_user_pk()
     currency.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The currency is updated successfully."), "success")
+    flash(s(lazy_gettext("The currency is updated successfully.")), "success")
     return redirect(inherit_next(__get_detail_uri(currency)))
 
 
@@ -161,7 +162,7 @@ def delete_currency(currency: Currency) -> redirect:
     """
     currency.delete()
     db.session.commit()
-    flash(lazy_gettext("The currency is deleted successfully."), "success")
+    flash(s(lazy_gettext("The currency is deleted successfully.")), "success")
     return redirect(or_next(url_for("accounting.currency.list")))
 
 
diff --git a/src/accounting/report/reports/income_expenses.py b/src/accounting/report/reports/income_expenses.py
index f91c36a..1571ecf 100644
--- a/src/accounting/report/reports/income_expenses.py
+++ b/src/accounting/report/reports/income_expenses.py
@@ -37,6 +37,7 @@ from accounting.report.utils.option_link import OptionLink
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
 from accounting.report.utils.urls import income_expenses_url
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 
 
@@ -120,7 +121,7 @@ class EntryCollector:
             else_=-JournalEntry.amount))
         select: sa.Select = sa.Select(balance_func)\
             .join(Transaction).join(Account)\
-            .filter(JournalEntry.currency_code == self.__currency.code,
+            .filter(be(JournalEntry.currency_code == self.__currency.code),
                     self.__account_condition,
                     Transaction.date < self.__period.start)
         balance: int | None = db.session.scalar(select)
@@ -342,7 +343,7 @@ class PageParams(BasePageParams):
                           self.account.id == 0)]
         in_use: sa.Select = sa.Select(JournalEntry.account_id)\
             .join(Account)\
-            .filter(JournalEntry.currency_code == self.currency.code,
+            .filter(be(JournalEntry.currency_code == self.currency.code),
                     sa.or_(Account.base_code.startswith("11"),
                            Account.base_code.startswith("12"),
                            Account.base_code.startswith("21"),
diff --git a/src/accounting/report/reports/ledger.py b/src/accounting/report/reports/ledger.py
index 43f9be8..70cb03e 100644
--- a/src/accounting/report/reports/ledger.py
+++ b/src/accounting/report/reports/ledger.py
@@ -36,6 +36,7 @@ from accounting.report.utils.option_link import OptionLink
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
 from accounting.report.utils.urls import ledger_url
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 
 
@@ -116,8 +117,8 @@ class EntryCollector:
             (JournalEntry.is_debit, JournalEntry.amount),
             else_=-JournalEntry.amount))
         select: sa.Select = sa.Select(balance_func).join(Transaction)\
-            .filter(JournalEntry.currency_code == self.__currency.code,
-                    JournalEntry.account_id == self.__account.id,
+            .filter(be(JournalEntry.currency_code == self.__currency.code),
+                    be(JournalEntry.account_id == self.__account.id),
                     Transaction.date < self.__period.start)
         balance: int | None = db.session.scalar(select)
         if balance is None:
@@ -303,7 +304,7 @@ class PageParams(BasePageParams):
         :return: The account options.
         """
         in_use: sa.Select = sa.Select(JournalEntry.account_id)\
-            .filter(JournalEntry.currency_code == self.currency.code)\
+            .filter(be(JournalEntry.currency_code == self.currency.code))\
             .group_by(JournalEntry.account_id)
         return [OptionLink(str(x), ledger_url(self.currency, x, self.period),
                            x.id == self.account.id)
diff --git a/src/accounting/report/reports/search.py b/src/accounting/report/reports/search.py
index 8abd93e..e5ac29d 100644
--- a/src/accounting/report/reports/search.py
+++ b/src/accounting/report/reports/search.py
@@ -32,6 +32,7 @@ from accounting.report.utils.base_report import BaseReport
 from accounting.report.utils.csv_export import csv_download
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 from accounting.utils.query import parse_query_keywords
 from .journal import get_csv_rows
@@ -124,7 +125,7 @@ class EntryCollector:
         try:
             txn_date = datetime.strptime(k, "%Y")
             conditions.append(
-                sa.extract("year", Transaction.date) == txn_date.year)
+                be(sa.extract("year", Transaction.date) == txn_date.year))
         except ValueError:
             pass
         try:
diff --git a/src/accounting/transaction/views.py b/src/accounting/transaction/views.py
index ca38ece..99b793a 100644
--- a/src/accounting/transaction/views.py
+++ b/src/accounting/transaction/views.py
@@ -28,6 +28,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Transaction
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.permission import has_permission, can_view, can_edit
@@ -87,7 +88,7 @@ def add_transaction(txn_type: TransactionType) -> redirect:
     form.populate_obj(txn)
     db.session.add(txn)
     db.session.commit()
-    flash(lazy_gettext("The transaction is added successfully"), "success")
+    flash(s(lazy_gettext("The transaction is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(txn)))
 
 
@@ -141,12 +142,13 @@ def update_transaction(txn: Transaction) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(txn)
     if not form.is_modified:
-        flash(lazy_gettext("The transaction was not modified."), "success")
+        flash(s(lazy_gettext("The transaction was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(txn)))
     txn.updated_by_id = get_current_user_pk()
     txn.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The transaction is updated successfully."), "success")
+    flash(s(lazy_gettext("The transaction is updated successfully.")),
+          "success")
     return redirect(inherit_next(__get_detail_uri(txn)))
 
 
@@ -162,7 +164,8 @@ def delete_transaction(txn: Transaction) -> redirect:
     txn.delete()
     sort_transactions_in(txn.date, txn.id)
     db.session.commit()
-    flash(lazy_gettext("The transaction is deleted successfully."), "success")
+    flash(s(lazy_gettext("The transaction is deleted successfully.")),
+          "success")
     return redirect(or_next(__get_default_page_uri()))
 
 
@@ -193,10 +196,10 @@ def sort_transactions(txn_date: date) -> redirect:
     form: TransactionReorderForm = TransactionReorderForm(txn_date)
     form.save_order()
     if not form.is_modified:
-        flash(lazy_gettext("The order was not modified."), "success")
+        flash(s(lazy_gettext("The order was not modified.")), "success")
         return redirect(or_next(__get_default_page_uri()))
     db.session.commit()
-    flash(lazy_gettext("The order is updated successfully."), "success")
+    flash(s(lazy_gettext("The order is updated successfully.")), "success")
     return redirect(or_next(__get_default_page_uri()))
 
 
diff --git a/src/accounting/utils/cast.py b/src/accounting/utils/cast.py
new file mode 100644
index 0000000..0908b65
--- /dev/null
+++ b/src/accounting/utils/cast.py
@@ -0,0 +1,43 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/15
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The utility to cast a SQLAlchemy column into the column type, to avoid
+warnings from the IDE.
+
+This module should not import any other module from the application.
+
+"""
+import typing as t
+
+import sqlalchemy as sa
+
+
+def be(expression: t.Any) -> sa.BinaryExpression:
+    """Casts the SQLAlchemy binary expression to the binary expression type.
+
+    :param expression: The binary expression.
+    :return: The binary expression itself.
+    """
+    return expression
+
+
+def s(message: t.Any) -> str:
+    """Casts the LazyString message to the string type.
+
+    :param message: The message.
+    :return: The binary expression itself.
+    """
+    return message