Merge pull request #10077 from zhang2014/fix/ISSUES-10056

ISSUES-10056 support identifier argument for MySQL Database engine

docs/en/engines/database_engines/mysql.md

@@ -3,7 +3,7 @@ toc_priority: 30
 toc_title: MySQL
 ---
 
-# Mysql {#mysql}
+# MySQL {#mysql}
 
 Allows to connect to databases on a remote MySQL server and perform `INSERT` and `SELECT` queries to exchange data between ClickHouse and MySQL.
 
@@ -19,7 +19,7 @@ You cannot perform the following queries:
 
 ``` sql
 CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
-ENGINE = MySQL('host:port', 'database', 'user', 'password')
+ENGINE = MySQL('host:port', ['database' | database], 'user', 'password')
 ```
 
 **Engine Parameters**

docs/ru/database_engines/mysql.md

@@ -6,8 +6,6 @@
 
 Не поддерживаемые виды запросов:
 
--   `ATTACH`/`DETACH`
--   `DROP`
 -   `RENAME`
 -   `CREATE TABLE`
 -   `ALTER`
@@ -16,7 +14,7 @@
 
 ``` sql
 CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
-ENGINE = MySQL('host:port', 'database', 'user', 'password')
+ENGINE = MySQL('host:port', ['database' | database], 'user', 'password')
 ```
 
 **Параметры движка**

docs/zh/engines/database_engines/mysql.md

@@ -7,8 +7,6 @@ MySQL引擎用于将远程的MySQL服务器中的表映射到ClickHouse中，并
 
 但您无法对其执行以下操作：
 
--   `ATTACH`/`DETACH`
--   `DROP`
 -   `RENAME`
 -   `CREATE TABLE`
 -   `ALTER`
@@ -17,7 +15,7 @@ MySQL引擎用于将远程的MySQL服务器中的表映射到ClickHouse中，并
 
 ``` sql
 CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
-ENGINE = MySQL('host:port', 'database', 'user', 'password')
+ENGINE = MySQL('host:port', ['database' | database], 'user', 'password')
 ```
 
 **MySQL数据库引擎参数**

src/Databases/DatabaseFactory.cpp

@@ -4,6 +4,7 @@
 #include <Databases/DatabaseMemory.h>
 #include <Databases/DatabaseOrdinary.h>
 #include <Parsers/ASTLiteral.h>
+#include <Parsers/ASTIdentifier.h>
 #include <Parsers/formatAST.h>
 #include <Parsers/ASTCreateQuery.h>
 #include <Parsers/ASTFunction.h>
@@ -15,6 +16,7 @@
 #if USE_MYSQL
 
 #include <Databases/DatabaseMySQL.h>
+#include <Interpreters/evaluateConstantExpression.h>
 
 #endif
 
@@ -49,6 +51,15 @@ DatabasePtr DatabaseFactory::get(
     }
 }
 
+template <typename ValueType>
+static inline ValueType safeGetLiteralValue(const ASTPtr &ast, const String &engine_name)
+{
+    if (!ast || !ast->as<ASTLiteral>())
+        throw Exception("Database engine " + engine_name + " requested literal argument.", ErrorCodes::BAD_ARGUMENTS);
+
+    return ast->as<ASTLiteral>()->value.safeGet<ValueType>();
+}
+
 DatabasePtr DatabaseFactory::getImpl(
     const String & database_name, const String & metadata_path, const ASTStorage * engine_define, Context & context)
 {
@@ -79,11 +90,14 @@ DatabasePtr DatabaseFactory::getImpl(
             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 & 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>();
+
+        ASTs & arguments = engine->arguments->children;
+        arguments[1] = evaluateConstantExpressionOrIdentifierAsLiteral(arguments[1], context);
+
+        const auto & host_name_and_port = safeGetLiteralValue<String>(arguments[0], "MySQL");
+        const auto & database_name_in_mysql = safeGetLiteralValue<String>(arguments[1], "MySQL");
+        const auto & mysql_user_name = safeGetLiteralValue<String>(arguments[2], "MySQL");
+        const auto & mysql_user_password = safeGetLiteralValue<String>(arguments[3], "MySQL");
 
         try
         {
@@ -114,7 +128,7 @@ DatabasePtr DatabaseFactory::getImpl(
 
         const auto & arguments = engine->arguments->children;
 
-        const auto cache_expiration_time_seconds = arguments[0]->as<ASTLiteral>()->value.safeGet<UInt64>();
+        const auto cache_expiration_time_seconds = safeGetLiteralValue<UInt64>(arguments[0], "Lazy");
         return std::make_shared<DatabaseLazy>(database_name, metadata_path, cache_expiration_time_seconds, context);
     }
 

tests/integration/test_mysql_database_engine/test.py

@@ -5,6 +5,7 @@ import pymysql.cursors
 import pytest
 
 from helpers.cluster import ClickHouseCluster
+from helpers.client import QueryRuntimeException
 
 cluster = ClickHouseCluster(__file__)
 clickhouse_node = cluster.add_instance('node1', main_configs=['configs/remote_servers.xml'], with_mysql=True)
@@ -92,7 +93,7 @@ def test_clickhouse_dml_for_mysql_database(started_cluster):
     with contextlib.closing(MySQLNodeInstance('root', 'clickhouse', '127.0.0.1', port=3308)) as mysql_node:
         mysql_node.query("CREATE DATABASE test_database DEFAULT CHARACTER SET 'utf8'")
         mysql_node.query('CREATE TABLE `test_database`.`test_table` ( `i``d` int(11) NOT NULL, PRIMARY KEY (`i``d`)) ENGINE=InnoDB;')
-        clickhouse_node.query("CREATE DATABASE test_database ENGINE = MySQL('mysql1:3306', 'test_database', 'root', 'clickhouse')")
+        clickhouse_node.query("CREATE DATABASE test_database ENGINE = MySQL('mysql1:3306', test_database, 'root', 'clickhouse')")
 
         assert clickhouse_node.query("SELECT count() FROM `test_database`.`test_table`").rstrip() == '0'
         clickhouse_node.query("INSERT INTO `test_database`.`test_table`(`i\`d`) select number from numbers(10000)")
@@ -120,3 +121,13 @@ def test_clickhouse_join_for_mysql_database(started_cluster):
                                      "LEFT JOIN default.t1_remote_mysql AS s_ref "
                                      "ON (s_ref.opco = s.opco AND s_ref.service = s.service)") == ''
         mysql_node.query("DROP DATABASE test")
+
+
+def test_bad_arguments_for_mysql_database_engine(started_cluster):
+    with contextlib.closing(MySQLNodeInstance('root', 'clickhouse', '127.0.0.1', port=3308)) as mysql_node:
+        with pytest.raises(QueryRuntimeException) as exception:
+            mysql_node.query("CREATE DATABASE IF NOT EXISTS test_bad_arguments DEFAULT CHARACTER SET 'utf8'")
+            clickhouse_node.query("CREATE DATABASE test_database ENGINE = MySQL('mysql1:3306', test_bad_arguments, root, 'clickhouse')")
+
+        assert 'Database engine MySQL requested literal argument.' in str(exception.value)
+        mysql_node.query("DROP DATABASE test_bad_arguments")