diff --git a/ocdb.cpp b/ocdb.cpp
index b9950d9..12cf1bb 100644
--- a/ocdb.cpp
+++ b/ocdb.cpp
@@ -55,8 +55,8 @@ bool OCdb::init(const std::string& dump_path) {
 		throw 1;
 
 	if (!request("CREATE TABLE IF NOT EXISTS revision (revision INTEGER PRIMARY KEY);") ||
-		!request("CREATE TABLE IF NOT EXISTS caches (code TEXT PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT);") ||
-		!request("CREATE TABLE IF NOT EXISTS logs (uuid TEXT PRIMARY KEY, cache_code TEXT, date TEXT, user TEXT, type INTEGER);") ||
+		!request("CREATE TABLE IF NOT EXISTS caches (code INTEGER PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT);") ||
+		!request("CREATE TABLE IF NOT EXISTS logs (uuid TEXT PRIMARY KEY, cache_code INTEGER, date TEXT, user TEXT, type INTEGER);") ||
 		!request("CREATE INDEX idx_user on logs (user, type);"))
 		throw 1;
 	request("COMMIT;");
@@ -119,7 +119,9 @@ bool OCdb::parse_item(const json& j) {
 			update_cache(j);
 		} else if (j.count("change_type") && j["change_type"] == "delete") {
 			Debug(2) << "Deleting cache " << j["object_key"]["code"].get<std::string>() << ".\n";
-			sql = "DELETE FROM caches WHERE code='" + j["object_key"]["code"].get<std::string>() + "';";
+			sql = "DELETE FROM caches WHERE code='";
+			sql += cache_code_to_int(j["object_key"]["code"].get<std::string>());
+			sql += "';";
 			request(sql);
 		} else {
 			Debug(1) << "Incorrect change type: " << j["change_type"] << ".\n";
@@ -142,14 +144,14 @@ bool OCdb::parse_item(const json& j) {
 }
 
 bool OCdb::update_cache(const json& j) {
-	// (code TEXT PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
+	// (code INTEGER PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
 	std::map<std::string, std::string> fields;
 	std::map<std::string, short> fields2;
 	int res;
 
 	if (!j.count("object_key") || !j["object_key"].count("code") || !j.count("data")) return 0;
 
-	std::string code = j["object_key"]["code"].get<std::string>();
+	int code = cache_code_to_int(j["object_key"]["code"].get<std::string>());
 	if (j["data"].count("names") && j["data"]["names"].count("pl") && !j["data"]["names"]["pl"].is_null())
 		fields["name"] = j["data"]["names"]["pl"].get<std::string>();
 	else if (j["data"].count("names") && j["data"]["names"].count("en") && !j["data"]["names"]["en"].is_null())
@@ -189,7 +191,7 @@ bool OCdb::update_cache(const json& j) {
 	for (auto& i : fields2)
 		sql += i.first + ',';
 	sql.pop_back();
-	sql += ") VALUES ('" + code + "',";
+	sql += ") VALUES ('" + std::to_string(code) + "',";
 	for (__attribute__((unused)) auto& i : fields)
 		sql += "?,";
 	for (__attribute__((unused)) auto& i : fields2)
@@ -227,7 +229,7 @@ bool OCdb::update_cache(const json& j) {
 }
 
 bool OCdb::update_log(const json& j) {
-	// logs (uuid TEXT PRIMARY KEY, cache_code TEXT, date TEXT, user TEXT, type TEXT);"))
+	// logs (uuid TEXT PRIMARY KEY, cache_code INTEGER, date TEXT, user TEXT, type TEXT);"))
 	std::map<std::string, std::string> fields;
 	std::map<std::string, short> fields2;
 	int res;
@@ -236,7 +238,7 @@ bool OCdb::update_log(const json& j) {
 
 	std::string uuid = j["object_key"]["uuid"].get<std::string>();
 	if (j["data"].count("cache_code") && !j["data"]["cache_code"].is_null())
-		fields["cache_code"] = j["data"]["cache_code"].get<std::string>();
+		fields2["cache_code"] = cache_code_to_int(j["data"]["cache_code"].get<std::string>());
 	if (j["data"].count("date") && !j["data"]["date"].is_null())
 		fields["date"] = j["data"]["date"].get<std::string>();
 	if (j["data"].count("user") && j["data"]["user"].count("uuid") && !j["data"]["user"]["uuid"].is_null())
@@ -337,7 +339,7 @@ Caches OCdb::get_user_caches_not_found(const std::string& uuid) const {
 	res = sqlite3_step(stmt);
 	while (res == SQLITE_ROW) {
 		Cache c;
-		if (sqlite3_column_text(stmt, 0)) c.code = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 0));
+		if (sqlite3_column_text(stmt, 0)) c.code = int_to_cache_code(sqlite3_column_int(stmt, 0));
 		if (sqlite3_column_text(stmt, 1)) c.pos = Position(reinterpret_cast<const char*>(sqlite3_column_text(stmt, 1)));
 		if (sqlite3_column_text(stmt, 2)) c.region = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 2));
 		c.status = ok;
@@ -357,7 +359,7 @@ Caches OCdb::get_user_caches_not_found(const std::string& uuid) const {
 Caches OCdb::get_user_caches(const std::string& uuid, __attribute__((unused)) int count) const {
 	int res;
 
-	//code TEXT PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
+	//code INTEGER PRIMARY KEY, name TEXT, location TEXT, type TEXT, status INTEGER, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
 	sql = "SELECT code, location, type, size, difficulty, terrain, country, region, owner, status, name FROM caches WHERE EXISTS (SELECT cache_code FROM logs WHERE cache_code = code AND type = ";
 	sql += found;
 	sql += " and user = ?);";
@@ -375,7 +377,7 @@ Caches OCdb::get_user_caches(const std::string& uuid, __attribute__((unused)) in
 Caches OCdb::get_user_caches_owned(const std::string& uuid) const {
 	int res;
 
-	//code TEXT PRIMARY KEY, name TEXT, location TEXT, type TEXT, status TEXT, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
+	//code INTEGER PRIMARY KEY, name TEXT, location TEXT, type TEXT, status TEXT, size TEXT, difficulty INTEGER, terrain INTEGER, country TEXT, region TEXT, owner TEXT)
 	sql = "SELECT code, location, type, size, difficulty, terrain, country, region, owner, status, name FROM caches WHERE owner = ?;";
 
 	res = sqlite3_prepare_v2(db, sql.c_str(), sql.length() + 1, &stmt, NULL);
@@ -395,7 +397,7 @@ Caches OCdb::parse_sql_caches() const {
 	res = sqlite3_step(stmt);
 	while (res == SQLITE_ROW) {
 		Cache c;
-		if (sqlite3_column_text(stmt, 0)) c.code = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 0));
+		if (sqlite3_column_text(stmt, 0)) c.code = int_to_cache_code(sqlite3_column_int(stmt, 0));
 		if (sqlite3_column_text(stmt, 1)) c.pos = Position(reinterpret_cast<const char*>(sqlite3_column_text(stmt, 1)));
 		if (sqlite3_column_text(stmt, 2)) c.type = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 2));
 		if (sqlite3_column_text(stmt, 3)) c.size = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 3));
@@ -479,3 +481,43 @@ std::map<std::string, int> OCdb::get_region_stats() {
 	sqlite3_finalize(stmt);
 	return count;
 }
+
+std::string OCdb::int_to_cache_code(int n) const {
+	const int n5 = 36 * 36 * 36 * 36;
+	const int n4 = 36 * 36 * 36;
+	const int n3 = 36 * 36;
+	const int n2 = 36;
+
+	int x;
+	std::stringstream ss;
+	ss << cache_code_prefix;
+
+	if (n >= n5) {
+		x = n/n5;
+		if (x >= 10) ss << static_cast<char>('A' + x - 10);
+		else ss << x;
+		n %= n5;
+	}
+	x = n/n4;
+	if (x >= 10) ss << static_cast<char>('A' + x - 10);
+	else ss << x;
+	n %= n4;
+	x = n/n3;
+	if (x >= 10) ss << static_cast<char>('A' + x - 10);
+	else ss << x;
+	n %= n3;
+	x = n/n2;
+	if (x >= 10) ss << static_cast<char>('A' + x - 10);
+	else ss << x;
+	n %= n2;
+	x = n;
+	if (x >= 10) ss << static_cast<char>('A' + x - 10);
+	else ss << x;
+
+	return ss.str();
+}
+
+int OCdb::cache_code_to_int(std::string code) const {
+	code = code.substr(2);
+    return std::stoi(code, nullptr, 36);
+}
diff --git a/ocdb.h b/ocdb.h
index b9285a6..673c46a 100644
--- a/ocdb.h
+++ b/ocdb.h
@@ -19,6 +19,10 @@ private:
 	mutable sqlite3_stmt* stmt;
 	mutable std::string sql;
 	int revision;
+	
+	std::string cache_code_prefix = "OP";
+	std::string int_to_cache_code(int n) const;
+	int cache_code_to_int(std::string code) const;
 
 	bool request(const std::string& req) const;
 	bool init_part(const std::string& json_file); // read db dump