Fixed error, removed partially duplicate code [#METR-22462].

dbms/include/DB/Interpreters/evaluateConstantExpression.h

@@ -10,10 +10,24 @@ namespace DB
 class IAST;
 class Context;
 
-/** Выполнить константное выражение.
-  * Используется в редких случаях - для элемента множества в IN, для данных для INSERT.
-  * Весьма неоптимально.
+/** Evaluate constant expression.
+  * Used in rare cases - for elements of set for IN, for data to INSERT.
+  * Quite suboptimal.
   */
 Field evaluateConstantExpression(std::shared_ptr<IAST> & node, const Context & context);
 
+
+/** Evaluate constant expression
+  *  and returns ASTLiteral with its value.
+  */
+std::shared_ptr<IAST> evaluateConstantExpressionAsLiteral(std::shared_ptr<IAST> & node, const Context & context);
+
+
+/** Evaluate constant expression
+  *  and returns ASTLiteral with its value.
+  * Also, if AST is identifier, then return string literal with its name.
+  * Useful in places where some name may be specified as identifier, or as result of a constant expression.
+  */
+std::shared_ptr<IAST> evaluateConstantExpressionOrIdentidierAsLiteral(std::shared_ptr<IAST> & node, const Context & context);
+
 }

dbms/include/DB/Interpreters/reinterpretAsIdentifier.h

-#pragma once
-
-#include <memory>
-
-
-namespace DB
-{
-
-class IAST;
-class ASTIdentifier;
-class Context;
-
-/** \brief if `expr` is not already ASTIdentifier evaluates it
-  *  and replaces by a new ASTIdentifier with the result of evaluation as its name.
-  *  `expr` must evaluate to a String type */
-ASTIdentifier & reinterpretAsIdentifier(std::shared_ptr<IAST> & expr, const Context & context);
-
-}

dbms/src/Interpreters/evaluateConstantExpression.cpp

@@ -17,7 +17,7 @@ namespace ErrorCodes
 	extern const int BAD_ARGUMENTS;
 }
 
-/** Выполнить константное выражение (для элемента множества в IN). Весьма неоптимально. */
+
 Field evaluateConstantExpression(ASTPtr & node, const Context & context)
 {
 	ExpressionActionsPtr expr_for_constant_folding = ExpressionAnalyzer(
@@ -44,4 +44,23 @@ Field evaluateConstantExpression(ASTPtr & node, const Context & context)
 	return result_column[0];
 }
 
+
+ASTPtr evaluateConstantExpressionAsLiteral(ASTPtr & node, const Context & context)
+{
+	if (typeid_cast<const ASTLiteral *>(node.get()))
+		return node;
+
+	return std::make_shared<ASTLiteral>(node->range,
+		evaluateConstantExpression(node, context));
+}
+
+
+ASTPtr evaluateConstantExpressionOrIdentidierAsLiteral(ASTPtr & node, const Context & context)
+{
+	if (const ASTIdentifier * id = typeid_cast<const ASTIdentifier *>(node.get()))
+		return std::make_shared<ASTLiteral>(node->range, Field(id->name));
+
+	return evaluateConstantExpressionAsLiteral(node, context);
+}
+
 }

dbms/src/Interpreters/reinterpretAsIdentifier.cpp

-#include <DB/Interpreters/Context.h>
-#include <DB/Interpreters/ExpressionAnalyzer.h>
-#include <DB/Interpreters/ExpressionActions.h>
-#include <DB/Interpreters/reinterpretAsIdentifier.h>
-#include <DB/DataTypes/DataTypeString.h>
-#include <DB/Parsers/ASTIdentifier.h>
-#include <DB/Parsers/ASTLiteral.h>
-
-
-namespace DB
-{
-
-namespace
-{
-	ASTPtr reinterpretAsIdentifierImpl(const ASTPtr & expr, const Context & context)
-	{
-		/// for string literal return its value
-		if (const auto literal = typeid_cast<const ASTLiteral *>(expr.get()))
-			return std::make_shared<ASTIdentifier>(StringRange(), safeGet<const String &>(literal->value));
-
-		/// otherwise evaluate the expression
-		Block block{};
-		/** pass a dummy column name because ExpressionAnalyzer
-			*  does not work with no columns so far. */
-		ExpressionAnalyzer{
-			expr, context, {},
-			{ { "", std::make_shared<DataTypeString>() } }
-		}.getActions(false)->execute(block);
-
-		const auto & column_name_type = block.getByName(expr->getColumnName());
-
-		/// ensure the result of evaluation has String type
-		if (!typeid_cast<const DataTypeString *>(column_name_type.type.get()))
-			throw Exception{"Expression must evaluate to a String"};
-
-		return std::make_shared<ASTIdentifier>(StringRange(), column_name_type.column->getDataAt(0).toString());
-	}
-}
-
-ASTIdentifier & reinterpretAsIdentifier(ASTPtr & expr, const Context & context)
-{
-	/// for identifier just return its name
-	if (!typeid_cast<const ASTIdentifier *>(expr.get()))
-		expr = reinterpretAsIdentifierImpl(expr, context);
-
-	return static_cast<ASTIdentifier &>(*expr);
-}
-
-}

dbms/src/Storages/StorageFactory.cpp

@@ -9,7 +9,7 @@
 #include <DB/Parsers/ASTLiteral.h>
 
 #include <DB/Interpreters/Context.h>
-#include <DB/Interpreters/reinterpretAsIdentifier.h>
+#include <DB/Interpreters/evaluateConstantExpression.h>
 #include <DB/Interpreters/getClusterName.h>
 
 #include <DB/Storages/StorageLog.h>
@@ -350,8 +350,11 @@ StoragePtr StorageFactory::get(
 				" - name of source database and regexp for table names.",
 				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
-		String source_database 		= reinterpretAsIdentifier(args[0], local_context).name;
-		String table_name_regexp	= safeGet<const String &>(typeid_cast<ASTLiteral &>(*args[1]).value);
+		args[0] = evaluateConstantExpressionOrIdentidierAsLiteral(args[0], local_context);
+		args[1] = evaluateConstantExpressionAsLiteral(args[1], local_context);
+
+		String source_database 		= static_cast<const ASTLiteral &>(*args[0]).value.safeGet<String>();
+		String table_name_regexp	= static_cast<const ASTLiteral &>(*args[1]).value.safeGet<String>();
 
 		return StorageMerge::create(
 			table_name, columns,
@@ -387,8 +390,11 @@ StoragePtr StorageFactory::get(
 
 		String cluster_name = getClusterName(*args[0]);
 
-		String remote_database 	= reinterpretAsIdentifier(args[1], local_context).name;
-		String remote_table 	= reinterpretAsIdentifier(args[2], local_context).name;
+		args[1] = evaluateConstantExpressionOrIdentidierAsLiteral(args[1], local_context);
+		args[2] = evaluateConstantExpressionOrIdentidierAsLiteral(args[2], local_context);
+
+		String remote_database 	= static_cast<const ASTLiteral &>(*args[1]).value.safeGet<String>();
+		String remote_table 	= static_cast<const ASTLiteral &>(*args[2]).value.safeGet<String>();
 
 		const auto & sharding_key = args.size() == 4 ? args[3] : nullptr;
 
@@ -421,8 +427,11 @@ StoragePtr StorageFactory::get(
 				" destination_database, destination_table, num_buckets, min_time, max_time, min_rows, max_rows, min_bytes, max_bytes.",
 				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
-		String destination_database = reinterpretAsIdentifier(args[0], local_context).name;
-		String destination_table 	= typeid_cast<ASTIdentifier &>(*args[1]).name;
+		args[1] = evaluateConstantExpressionOrIdentidierAsLiteral(args[1], local_context);
+		args[2] = evaluateConstantExpressionOrIdentidierAsLiteral(args[2], local_context);
+
+		String destination_database = static_cast<const ASTLiteral &>(*args[1]).value.safeGet<String>();
+		String destination_table 	= static_cast<const ASTLiteral &>(*args[2]).value.safeGet<String>();
 
 		size_t num_buckets = apply_visitor(FieldVisitorConvertToNumber<size_t>(), typeid_cast<ASTLiteral &>(*args[2]).value);
 

dbms/src/TableFunctions/TableFunctionMerge.cpp

@@ -5,7 +5,7 @@
 #include <DB/Parsers/ASTIdentifier.h>
 #include <DB/Parsers/ASTLiteral.h>
 #include <DB/TableFunctions/ITableFunction.h>
-#include <DB/Interpreters/reinterpretAsIdentifier.h>
+#include <DB/Interpreters/evaluateConstantExpression.h>
 #include <DB/Databases/IDatabase.h>
 #include <DB/TableFunctions/TableFunctionMerge.h>
 
@@ -66,8 +66,11 @@ StoragePtr TableFunctionMerge::execute(ASTPtr ast_function, Context & context) c
 			" - name of source database and regexp for table names.",
 			ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
-	String source_database 		= reinterpretAsIdentifier(args[0], context).name;
-	String table_name_regexp	= safeGet<const String &>(typeid_cast<ASTLiteral &>(*args[1]).value);
+	args[0] = evaluateConstantExpressionOrIdentidierAsLiteral(args[1], context);
+	args[1] = evaluateConstantExpressionAsLiteral(args[2], context);
+
+	String source_database 		= static_cast<const ASTLiteral &>(*args[0]).value.safeGet<String>();
+	String table_name_regexp	= static_cast<const ASTLiteral &>(*args[1]).value.safeGet<String>();
 
 	/// В InterpreterSelectQuery будет создан ExpressionAnalzyer, который при обработке запроса наткнется на этот Identifier.
 	/// Нам необходимо его пометить как имя базы данных, поскольку по умолчанию стоит значение column

dbms/src/TableFunctions/TableFunctionRemote.cpp

@@ -2,7 +2,7 @@
 #include <DB/Storages/StorageDistributed.h>
 #include <DB/Parsers/ASTIdentifier.h>
 #include <DB/Parsers/ASTLiteral.h>
-#include <DB/Interpreters/reinterpretAsIdentifier.h>
+#include <DB/Interpreters/evaluateConstantExpression.h>
 #include <DB/Interpreters/Cluster.h>
 
 #include <DB/TableFunctions/TableFunctionRemote.h>
@@ -210,7 +210,8 @@ StoragePtr TableFunctionRemote::execute(ASTPtr ast_function, Context & context)
 	description = getStringLiteral(*args[arg_num], "Hosts pattern");
 	++arg_num;
 
-	remote_database = reinterpretAsIdentifier(args[arg_num], context).name;
+	args[arg_num] = evaluateConstantExpressionOrIdentidierAsLiteral(args[arg_num], context);
+	remote_database = static_cast<const ASTLiteral &>(*args[arg_num]).value.safeGet<String>();
 	++arg_num;
 
 	size_t dot = remote_database.find('.');
@@ -225,7 +226,8 @@ StoragePtr TableFunctionRemote::execute(ASTPtr ast_function, Context & context)
 		if (arg_num >= args.size())
 			throw Exception(err, ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
-		remote_table = reinterpretAsIdentifier(args[arg_num], context).name;
+		args[arg_num] = evaluateConstantExpressionOrIdentidierAsLiteral(args[arg_num], context);
+		remote_table = static_cast<const ASTLiteral &>(*args[arg_num]).value.safeGet<String>();
 		++arg_num;
 	}
 

dbms/src/TableFunctions/TableFunctionShardByHash.cpp

@@ -2,7 +2,7 @@
 #include <DB/Storages/StorageDistributed.h>
 #include <DB/Parsers/ASTIdentifier.h>
 #include <DB/Parsers/ASTLiteral.h>
-#include <DB/Interpreters/reinterpretAsIdentifier.h>
+#include <DB/Interpreters/evaluateConstantExpression.h>
 #include <DB/Interpreters/Cluster.h>
 #include <DB/Interpreters/getClusterName.h>
 #include <DB/Common/SipHash.h>
@@ -52,8 +52,12 @@ StoragePtr TableFunctionShardByHash::execute(ASTPtr ast_function, Context & cont
 
 	cluster_name = getClusterName(*args[0]);
 	key = getStringLiteral(*args[1], "Key to hash");
-	remote_database = reinterpretAsIdentifier(args[2], context).name;
-	remote_table = reinterpretAsIdentifier(args[3], context).name;
+
+	args[2] = evaluateConstantExpressionOrIdentidierAsLiteral(args[2], context);
+	args[3] = evaluateConstantExpressionOrIdentidierAsLiteral(args[3], context);
+
+	remote_database = static_cast<const ASTLiteral &>(*args[2]).value.safeGet<String>();
+	remote_table = static_cast<const ASTLiteral &>(*args[3]).value.safeGet<String>();
 
 	/// Аналогично другим TableFunctions.
 	for (auto & arg : args)