From 1aac3a5c9dff467edbec8a1faea9dc45cbf26035 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Tue, 3 Mar 2020 12:05:17 +0300
Subject: [PATCH] Fixing defaults

---
 .../Interpreters/InterpreterCreateQuery.cpp   | 10 +-------
 dbms/src/Storages/ColumnsDescription.cpp      | 24 ++++++++++++++++++-
 dbms/src/Storages/ColumnsDescription.h        |  1 +
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/dbms/src/Interpreters/InterpreterCreateQuery.cpp b/dbms/src/Interpreters/InterpreterCreateQuery.cpp
index 4f7f1f98fbd..2aa2810dbc9 100644
--- a/dbms/src/Interpreters/InterpreterCreateQuery.cpp
+++ b/dbms/src/Interpreters/InterpreterCreateQuery.cpp
@@ -315,15 +315,7 @@ ColumnsDescription InterpreterCreateQuery::getColumnsDescription(const ASTExpres
     Block defaults_sample_block;
     /// set missing types and wrap default_expression's in a conversion-function if necessary
     if (!default_expr_list->children.empty())
-    {
-        auto syntax_analyzer_result = SyntaxAnalyzer(context).analyze(default_expr_list, column_names_and_types);
-        const auto actions = ExpressionAnalyzer(default_expr_list, syntax_analyzer_result, context).getActions(true);
-        for (auto & action : actions->getActions())
-            if (action.type == ExpressionAction::Type::JOIN || action.type == ExpressionAction::Type::ARRAY_JOIN)
-                throw Exception("Cannot CREATE table. Unsupported default value that requires ARRAY JOIN or JOIN action", ErrorCodes::THERE_IS_NO_DEFAULT_VALUE);
-
-        defaults_sample_block = actions->getSampleBlock();
-    }
+        defaults_sample_block = validateColumnsDefaultsAndGetSampleBlock(default_expr_list, column_names_and_types, context);
 
     ColumnsDescription res;
     auto name_type_it = column_names_and_types.begin();
diff --git a/dbms/src/Storages/ColumnsDescription.cpp b/dbms/src/Storages/ColumnsDescription.cpp
index 8b491679138..b923e9e255e 100644
--- a/dbms/src/Storages/ColumnsDescription.cpp
+++ b/dbms/src/Storages/ColumnsDescription.cpp
@@ -5,6 +5,8 @@
 #include <Parsers/ParserCreateQuery.h>
 #include <Parsers/parseQuery.h>
 #include <Parsers/queryToString.h>
+#include <Parsers/ASTSubquery.h>
+#include <Parsers/ASTSelectQuery.h>
 #include <IO/WriteBuffer.h>
 #include <IO/WriteHelpers.h>
 #include <IO/ReadBuffer.h>
@@ -20,7 +22,9 @@
 #include <Storages/IStorage.h>
 #include <Common/typeid_cast.h>
 #include <Compression/CompressionFactory.h>
-
+#include <Interpreters/ExpressionAnalyzer.h>
+#include <Interpreters/SyntaxAnalyzer.h>
+#include <Interpreters/ExpressionActions.h>
 
 namespace DB
 {
@@ -30,6 +34,7 @@ namespace ErrorCodes
     extern const int NO_SUCH_COLUMN_IN_TABLE;
     extern const int ILLEGAL_COLUMN;
     extern const int CANNOT_PARSE_TEXT;
+    extern const int THERE_IS_NO_DEFAULT_VALUE;
 }
 
 ColumnDescription::ColumnDescription(String name_, DataTypePtr type_, bool is_virtual_)
@@ -421,4 +426,21 @@ ColumnsDescription ColumnsDescription::parse(const String & str)
     return result;
 }
 
+
+Block validateColumnsDefaultsAndGetSampleBlock(ASTPtr default_expr_list, const NamesAndTypesList & all_columns, const Context & context)
+{
+    for (const auto & child : default_expr_list->children)
+        if (child->as<ASTSelectQuery>() || child->as<ASTSubquery>())
+            throw Exception("Select query is not allowed in columns DEFAULT expression", ErrorCodes::THERE_IS_NO_DEFAULT_VALUE);
+
+    auto syntax_analyzer_result = SyntaxAnalyzer(context).analyze(default_expr_list, all_columns);
+    const auto actions = ExpressionAnalyzer(default_expr_list, syntax_analyzer_result, context).getActions(true);
+    for (auto & action : actions->getActions())
+        if (action.type == ExpressionAction::Type::JOIN || action.type == ExpressionAction::Type::ARRAY_JOIN)
+            throw Exception(
+                "Unsupported default value that requires ARRAY JOIN or JOIN action",
+                ErrorCodes::THERE_IS_NO_DEFAULT_VALUE);
+
+    return actions->getSampleBlock();
+}
 }
diff --git a/dbms/src/Storages/ColumnsDescription.h b/dbms/src/Storages/ColumnsDescription.h
index d0d042498fa..254be091b6b 100644
--- a/dbms/src/Storages/ColumnsDescription.h
+++ b/dbms/src/Storages/ColumnsDescription.h
@@ -114,4 +114,5 @@ private:
     Container columns;
 };
 
+Block validateColumnsDefaultsAndGetSampleBlock(ASTPtr default_expr_list, const NamesAndTypesList & all_columns, const Context & context);
 }