optimize drop tables

src/Interpreters/DDLTask.cpp

@@ -16,7 +16,6 @@
 #include <Parsers/parseQuery.h>
 #include <Parsers/queryToString.h>
 #include <Parsers/ASTQueryWithTableAndOutput.h>
-#include <Parsers/ASTDropQuery.h>
 
 
 namespace DB
@@ -201,14 +200,6 @@ void DDLTaskBase::parseQueryFromEntry(ContextPtr context)
     ParserQuery parser_query(end, settings.allow_settings_after_format_in_insert);
     String description;
     query = parseQuery(parser_query, begin, end, description, 0, settings.max_parser_depth, settings.max_parser_backtracks);
-    if (auto * query_drop = query->as<ASTDropQuery>())
-    {
-        ASTs drops = query_drop->getRewrittenASTsOfSingleTable();
-        if (drops.size() > 1)
-            throw Exception(ErrorCodes::LOGICAL_ERROR, "Not supports drop multiple tables for ddl task.");
-
-        query = drops[0];
-    }
 }
 
 void DDLTaskBase::formatRewrittenQuery(ContextPtr context)

src/Interpreters/InterpreterDropQuery.cpp

@@ -557,7 +557,7 @@ bool InterpreterDropQuery::supportsTransactions() const
     return drop.cluster.empty()
             && !drop.temporary
             && drop.kind == ASTDropQuery::Kind::Truncate
-            && drop.database_and_tables;
+            && drop.table;
 }
 
 void registerInterpreterDropQuery(InterpreterFactory & factory)

src/Parsers/ASTDropQuery.h

@@ -40,7 +40,7 @@ public:
     // We detach the object permanently, so it will not be reattached back during server restart.
     bool permanently{false};
 
-    /// Example: Drop TABLE t1, t2, t3...
+    /// Used to drop multiple tables only, example: Drop TABLE t1, t2, t3...
     ASTPtr database_and_tables;
 
     /** Get the text that identifies this element. */
@@ -52,6 +52,7 @@ public:
         return removeOnCluster<ASTDropQuery>(clone(), params.default_database);
     }
 
+    /** Convert an AST that deletes multiple tables into multiple ASTs that delete a single table. */
     ASTs getRewrittenASTsOfSingleTable();
 
     QueryKind getQueryKind() const override { return QueryKind::Drop; }

src/Parsers/ParserDropQuery.cpp

@@ -7,6 +7,11 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+    extern const int SYNTAX_ERROR;
+}
+
 namespace
 {
 
@@ -84,6 +89,9 @@ bool parseDropQuery(IParser::Pos & pos, ASTPtr & node, Expected & expected, cons
 
         if (!tables_p.parse(pos, database_and_tables, expected))
             return false;
+
+        if (database_and_tables->size() > 1 && kind != ASTDropQuery::Kind::Drop)
+            throw Exception(ErrorCodes::SYNTAX_ERROR, "Only Support DROP multiple tables currently");
     }
 
     /// common for tables / dictionaries / databases
@@ -123,6 +131,9 @@ bool parseDropQuery(IParser::Pos & pos, ASTPtr & node, Expected & expected, cons
 
     query->cluster = cluster_str;
 
+    if (database_and_tables && database_and_tables->size() == 1)
+        node = query->getRewrittenASTsOfSingleTable()[0];
+
     return true;
 }
 

src/Parsers/tests/gtest_dictionary_parser.cpp

@@ -301,10 +301,8 @@ TEST(ParserDictionaryDDL, ParseDropQuery)
     ASTDropQuery * drop1 = ast1->as<ASTDropQuery>();
 
     EXPECT_TRUE(drop1->is_dictionary);
-    auto & database_and_tables1 = drop1->database_and_tables->as<ASTExpressionList &>();
-    auto identifier1 = dynamic_pointer_cast<ASTTableIdentifier>(database_and_tables1.children[0]);
-    EXPECT_EQ(identifier1->getDatabaseName(), "test");
-    EXPECT_EQ(identifier1->shortName(), "dict1");
+    EXPECT_EQ(drop1->getDatabase(), "test");
+    EXPECT_EQ(drop1->getTable(), "dict1");
     auto str1 = serializeAST(*drop1);
     EXPECT_EQ(input1, str1);
 
@@ -314,10 +312,8 @@ TEST(ParserDictionaryDDL, ParseDropQuery)
     ASTDropQuery * drop2 = ast2->as<ASTDropQuery>();
 
     EXPECT_TRUE(drop2->is_dictionary);
-    auto & database_and_tables2 = drop2->database_and_tables->as<ASTExpressionList &>();
-    auto identifier2 = dynamic_pointer_cast<ASTTableIdentifier>(database_and_tables2.children[0]);
-    EXPECT_EQ(identifier2->getDatabaseName(), "");
-    EXPECT_EQ(identifier2->shortName(), "dict2");
+    EXPECT_EQ(drop2->getDatabase(), "");
+    EXPECT_EQ(drop2->getTable(), "dict2");
     auto str2 = serializeAST(*drop2);
     EXPECT_EQ(input2, str2);
 }

tests/queries/0_stateless/02961_drop_tables.reference

@@ -6,3 +6,6 @@ Test when deletion of existing table fails
 -- check which tables exist in 02961_db1
 -- check which tables exist in 02961_db2
 02961_tb5
+Test when deletion of not empty table fails
+tab2
+tab3

tests/queries/0_stateless/02961_drop_tables.sql

@@ -27,6 +27,20 @@ SHOW TABLES FROM 02961_db1;
 SELECT '-- check which tables exist in 02961_db2';
 SHOW TABLES FROM 02961_db2;
 
+DROP TABLE IF EXISTS tab1, tab2, tab3;
+CREATE TABLE IF NOT EXISTS tab1 (id UInt32) Engine=Memory();
+CREATE TABLE IF NOT EXISTS tab2 (id UInt32) Engine=Memory();
+CREATE TABLE IF NOT EXISTS tab3 (id UInt32) Engine=Memory();
+
+INSERT INTO tab2 SELECT number FROM system.numbers limit 10;
+
+DROP TABLE IF EMPTY tab1, tab2, tab3; -- { serverError TABLE_NOT_EMPTY }
+SELECT 'Test when deletion of not empty table fails';
+SHOW TABLES;
+
+TRUNCATE TABLE tab2, tab3; -- { clientError SYNTAX_ERROR }
+
+DROP TABLE IF EXISTS tab1, tab2, tab3;
 
 DROP DATABASE IF EXISTS 02961_db1;
 DROP DATABASE IF EXISTS 02961_db2;