From 59f5f2d03cb9896928fbf8daa5be77806d3c5226 Mon Sep 17 00:00:00 2001
From: feng lv <fenglv15@mails.ucas.ac.cn>
Date: Thu, 6 May 2021 13:07:36 +0000
Subject: [PATCH] Add hints for enum names

add test
---
 src/DataTypes/EnumValues.cpp                        | 13 ++++++++++++-
 src/DataTypes/EnumValues.h                          |  7 +++++--
 .../0_stateless/01852_hints_enum_name.reference     |  1 +
 tests/queries/0_stateless/01852_hints_enum_name.sh  |  8 ++++++++
 4 files changed, 26 insertions(+), 3 deletions(-)
 create mode 100644 tests/queries/0_stateless/01852_hints_enum_name.reference
 create mode 100755 tests/queries/0_stateless/01852_hints_enum_name.sh

diff --git a/src/DataTypes/EnumValues.cpp b/src/DataTypes/EnumValues.cpp
index d4ca7e4dfdd..39c24bf1122 100644
--- a/src/DataTypes/EnumValues.cpp
+++ b/src/DataTypes/EnumValues.cpp
@@ -66,11 +66,22 @@ T EnumValues<T>::getValue(StringRef field_name, bool try_treat_as_id) const
             if (tmp_buf.eof() && value_to_name_map.find(x) != value_to_name_map.end())
                 return x;
         }
-        throw Exception{"Unknown element '" + field_name.toString() + "' for enum", ErrorCodes::BAD_ARGUMENTS};
+        auto hints = this->getHints(field_name.toString());
+        auto hints_string = !hints.empty() ? ", may be you meant: " + toString(hints) : "";
+        throw Exception{"Unknown element '" + field_name.toString() + "' for enum" + hints_string, ErrorCodes::BAD_ARGUMENTS};
     }
     return it->getMapped();
 }
 
+template <typename T>
+Names EnumValues<T>::getAllRegisteredNames() const
+{
+    Names result;
+    for (const auto & value : values)
+        result.emplace_back(value.first);
+    return result;
+}
+
 template class EnumValues<Int8>;
 template class EnumValues<Int16>;
 
diff --git a/src/DataTypes/EnumValues.h b/src/DataTypes/EnumValues.h
index 45ac30f9cd7..d03a8867e42 100644
--- a/src/DataTypes/EnumValues.h
+++ b/src/DataTypes/EnumValues.h
@@ -1,7 +1,8 @@
 #pragma once
 
-#include <Common/HashTable/HashMap.h>
 #include <unordered_map>
+#include <Common/HashTable/HashMap.h>
+#include <Common/NamePrompter.h>
 
 namespace DB
 {
@@ -12,7 +13,7 @@ namespace ErrorCodes
 }
 
 template <typename T>
-class EnumValues
+class EnumValues : public IHints<1, EnumValues<T>>
 {
 public:
     using Value = std::pair<std::string, T>;
@@ -65,6 +66,8 @@ public:
 
         return std::all_of(rhs_values.begin(), rhs_values.end(), check);
     }
+
+    Names getAllRegisteredNames() const override;
 };
 
 }
diff --git a/tests/queries/0_stateless/01852_hints_enum_name.reference b/tests/queries/0_stateless/01852_hints_enum_name.reference
new file mode 100644
index 00000000000..d86bac9de59
--- /dev/null
+++ b/tests/queries/0_stateless/01852_hints_enum_name.reference
@@ -0,0 +1 @@
+OK
diff --git a/tests/queries/0_stateless/01852_hints_enum_name.sh b/tests/queries/0_stateless/01852_hints_enum_name.sh
new file mode 100755
index 00000000000..bffde6e6c8c
--- /dev/null
+++ b/tests/queries/0_stateless/01852_hints_enum_name.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+$CLICKHOUSE_CLIENT --query="SELECT CAST('Helo', 'Enum(\'Hello\' = 1, \'World\' = 2)')" 2>&1 | grep -q "may be you meant: \['Hello'\]" && echo 'OK' || echo 'FAIL'
+