ISSUES-6063 support drop mysql database engine

dbms/src/Common/ErrorCodes.cpp

@@ -474,6 +474,7 @@ namespace ErrorCodes
     extern const int NOT_ENOUGH_PRIVILEGES = 497;
     extern const int LIMIT_BY_WITH_TIES_IS_NOT_SUPPORTED = 498;
     extern const int S3_ERROR = 499;
+    extern const int CANNOT_CREATE_DATABASE = 500;
 
     extern const int KEEPER_EXCEPTION = 999;
     extern const int POCO_EXCEPTION = 1000;

dbms/src/Databases/DatabaseFactory.cpp

@@ -9,6 +9,9 @@
 #include <Parsers/ASTFunction.h>
 #include <Common/parseAddress.h>
 #include "config_core.h"
+#include "DatabaseFactory.h"
+#include <Poco/File.h>
+
 #if USE_MYSQL
 
 #include <Databases/DatabaseMySQL.h>
@@ -21,15 +24,32 @@ namespace DB
 
 namespace ErrorCodes
 {
-extern const int BAD_ARGUMENTS;
-extern const int UNKNOWN_DATABASE_ENGINE;
+    extern const int BAD_ARGUMENTS;
+    extern const int UNKNOWN_DATABASE_ENGINE;
+    extern const int CANNOT_CREATE_DATABASE;
 }
 
 DatabasePtr DatabaseFactory::get(
-    const String & database_name,
-    const String & metadata_path,
-    const ASTStorage * engine_define,
-    Context & context)
+    const String & database_name, const String & metadata_path, const ASTStorage * engine_define, Context & context)
+{
+    try
+    {
+        Poco::File(metadata_path).createDirectory();
+        return getImpl(database_name, metadata_path, engine_define, context);
+    }
+    catch (...)
+    {
+        Poco::File metadata_dir(metadata_path);
+
+        if (metadata_dir.exists())
+            metadata_dir.remove(true);
+
+        throw;
+    }
+}
+
+DatabasePtr DatabaseFactory::getImpl(
+    const String & database_name, const String & metadata_path, const ASTStorage * engine_define, Context & context)
 {
     String engine_name = engine_define->engine->name;
 
@@ -55,20 +75,31 @@ DatabasePtr DatabaseFactory::get(
         const ASTFunction * engine = engine_define->engine;
 
         if (!engine->arguments || engine->arguments->children.size() != 4)
-            throw Exception(
-                "MySQL Database require mysql_hostname, mysql_database_name, mysql_username, mysql_password arguments.",
-                ErrorCodes::BAD_ARGUMENTS);
+            throw Exception("MySQL Database require mysql_hostname, mysql_database_name, mysql_username, mysql_password arguments.",
+                            ErrorCodes::BAD_ARGUMENTS);
 
         const auto & arguments = engine->arguments->children;
-
-        const auto & mysql_host_name = arguments[0]->as<ASTLiteral>()->value.safeGet<String>();
-        const auto & mysql_database_name = arguments[1]->as<ASTLiteral>()->value.safeGet<String>();
+        const auto & host_name_and_port = arguments[0]->as<ASTLiteral>()->value.safeGet<String>();
+        const auto & database_name_in_mysql = arguments[1]->as<ASTLiteral>()->value.safeGet<String>();
         const auto & mysql_user_name = arguments[2]->as<ASTLiteral>()->value.safeGet<String>();
         const auto & mysql_user_password = arguments[3]->as<ASTLiteral>()->value.safeGet<String>();
 
-        auto parsed_host_port = parseAddress(mysql_host_name, 3306);
-        return std::make_shared<DatabaseMySQL>(context, database_name, parsed_host_port.first, parsed_host_port.second, mysql_database_name,
-            mysql_user_name, mysql_user_password);
+        try
+        {
+            const auto & [remote_host_name, remote_port] = parseAddress(host_name_and_port, 3306);
+            auto mysql_pool = mysqlxx::Pool(database_name_in_mysql, remote_host_name, mysql_user_name, mysql_user_password, remote_port);
+
+            auto mysql_database = std::make_shared<DatabaseMySQL>(
+                context, database_name, metadata_path, engine_define, database_name_in_mysql, std::move(mysql_pool));
+
+            mysql_database->empty(context); /// test database is works fine.
+            return mysql_database;
+        }
+        catch (...)
+        {
+            const auto & exception_message = getCurrentExceptionMessage(true);
+            throw Exception("Cannot create MySQL database, because " + exception_message, ErrorCodes::CANNOT_CREATE_DATABASE);
+        }
     }
 
 #endif

dbms/src/Databases/DatabaseFactory.h

@@ -11,11 +11,9 @@ class ASTStorage;
 class DatabaseFactory
 {
 public:
-    static DatabasePtr get(
-        const String & database_name,
-        const String & metadata_path,
-        const ASTStorage * engine_define,
-        Context & context);
+    static DatabasePtr get(const String & database_name, const String & metadata_path, const ASTStorage * engine_define, Context & context);
+
+    static DatabasePtr getImpl(const String & database_name, const String & metadata_path, const ASTStorage * engine_define, Context & context);
 };
 
 }