From ef6023330df058c6e1fd47d5a2a5d400311cbd6d Mon Sep 17 00:00:00 2001
From: Alexey <alex@oblat.lv>
Date: Wed, 22 Oct 2025 15:05:12 +0300
Subject: [PATCH]

---
 com/Access/_common.lua | 22 ++++++++++++++++++++++
 com/Access/_errors.lua | 30 ++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 com/Access/_common.lua
 create mode 100644 com/Access/_errors.lua

diff --git a/com/Access/_common.lua b/com/Access/_common.lua
new file mode 100644
index 0000000..bd7e940
--- /dev/null
+++ b/com/Access/_common.lua
@@ -0,0 +1,22 @@
+-- File com/Access/_common.lua
+--
+-- Created at 2025-21-10
+--
+-- Description:
+--- Common functions for Unit module
+
+local common = {}
+
+function common.CheckMissingElement(arr, cmp)
+  local is_missing = {}
+  local ok = true
+  for _, key in ipairs(arr) do
+    if cmp[key] == nil then
+      table.insert(is_missing, key)
+      ok = false
+    end
+  end
+  return ok, is_missing
+end
+
+return common
\ No newline at end of file
diff --git a/com/Access/_errors.lua b/com/Access/_errors.lua
new file mode 100644
index 0000000..f9cf714
--- /dev/null
+++ b/com/Access/_errors.lua
@@ -0,0 +1,30 @@
+-- File com/Access/_errors.lua
+--
+-- Created at 2025-21-10
+-- Description:
+--- Centralized error definitions for Access operations
+--- to keep API responses consistent and clean.
+
+local errors = {
+  -- Common validation
+  MISSING_PARAMS = { code = -32602, message = "Missing params" },
+  INVALID_FIELD_TYPE = { code = -32602, message = "'fields' must be a non-empty table" },
+  INVALID_BY_PARAM = { code = -32602, message = "Invalid 'by' param" },
+  NO_VALID_FIELDS = { code = -32604, message = "No valid fields to update" },
+
+  -- Existence / duplication
+  UNIT_NOT_FOUND = { code = -32102, message = "Unit is not exists" },
+  UNIT_EXISTS = { code = -32101, message = "Unit is already exists" },
+
+  -- Database & constraint
+  UNIQUE_CONSTRAINT = { code = -32602, message = "Unique constraint failed" },
+  DB_QUERY_FAILED = { code = -32001, message = "Database query failed" },
+  DB_EXEC_FAILED = { code = -32002, message = "Database execution failed" },
+  DB_INSERT_FAILED = { code = -32003, message = "Failed to create unit" },
+  DB_DELETE_FAILED = { code = -32004, message = "Failed to delete unit" },
+
+  -- Generic fallback
+  UNKNOWN = { code = -32099, message = "Unexpected internal error" },
+}
+
+return errors