Allow compiling of clickhouse with old compiler

.gitignore

@@ -123,6 +123,7 @@ deps/libhttpserver/libhttpserver-0.18.1/
 #clickhouse
 deps/clickhouse-cpp/clickhouse-cpp-*
 deps/cityhash/cityhash/
+deps/cityhash/config*
 deps/lz4/lz4-1.7.5/
 deps/lz4/lz4/
 

Makefile

@@ -58,7 +58,6 @@ USERCHECK := $(shell getent passwd proxysql)
 GROUPCHECK := $(shell getent group proxysql)
 
 
-
 .PHONY: default
 default: build_deps build_lib build_src
 

lib/ClickHouse_Server.cpp

@@ -98,7 +98,11 @@ inline void ClickHouse_to_MySQL(const Block& block) {
 				is_null = 0;
 			} else {
 				auto s_t = bi.Column()->As<ColumnNullable>();
+#ifdef CXX17
 				cc = s_t->Nested()->GetType().GetCode();
+#else
+				cc = s_t->Type()->GetNestedType()->GetCode();
+#endif // CXX17
 			}
 
 			if (cc >= clickhouse::Type::Code::Int8 && cc <= clickhouse::Type::Code::Float64) {