diff --git a/DataStorage/DataId.cpp b/DataStorage/DataId.cpp
index 243ebd8..4a55cf0 100644
--- a/DataStorage/DataId.cpp
+++ b/DataStorage/DataId.cpp
@@ -19,6 +19,16 @@ std::string DataId::Table() const
 	return m_table;
 }
 
+int DataId::Min()
+{
+	return 0;
+}
+
+int DataId::Max()
+{
+	return 3;
+}
+
 int DataId::GetId(const std::string& dataName) const
 {
 	if (StringAlgorithm::iequals(dataName, "voltage"))
@@ -37,6 +47,9 @@ int DataId::GetId(const std::string& dataName) const
 		  StringAlgorithm::iequals(dataName, "forecast"))
 		return 2;
 
+	if (StringAlgorithm::iequals(dataName, "dewpoint"))
+		return 3;
+
 	return -1;
 }
 
diff --git a/include/DataId.h b/include/DataId.h
index 3a8f8fb..8429201 100644
--- a/include/DataId.h
+++ b/include/DataId.h
@@ -14,6 +14,10 @@ public:
 	int Id() const;
 	std::string Table() const;
 
+public:
+	static int Min();
+	static int Max();
+
 private:
 	int GetId(const std::string& dataName) const;