From 5eba20e1198b0bcd3fa91caa2a597e53cd5432fd Mon Sep 17 00:00:00 2001
From: taiyang-li <654010905@qq.com>
Date: Tue, 15 Nov 2022 09:46:24 +0800
Subject: [PATCH] modify return type from Int64 to UInt64

---
 docs/en/sql-reference/functions/math-functions.md | 2 +-
 src/Functions/factorial.cpp                       | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/en/sql-reference/functions/math-functions.md b/docs/en/sql-reference/functions/math-functions.md
index 7f349686d8b..47c27268b09 100644
--- a/docs/en/sql-reference/functions/math-functions.md
+++ b/docs/en/sql-reference/functions/math-functions.md
@@ -553,7 +553,7 @@ Result:
 
 ## factorial(n)
 
-Computes the factorial of an integer value. It works with any native integer type including UInt(8|16|32|64) and Int(8|16|32|64). The return type is Int64.
+Computes the factorial of an integer value. It works with any native integer type including UInt(8|16|32|64) and Int(8|16|32|64). The return type is UInt64.
 
 The factorial of 0 is 1. Likewise, the factorial() function returns 1 for any negative value. The maximum positive value for the input argument is 20, a value of 21 or greater overflows the range for Int64 and will cause exception throw.
 
diff --git a/src/Functions/factorial.cpp b/src/Functions/factorial.cpp
index 5c46b97c193..b76ef90a48d 100644
--- a/src/Functions/factorial.cpp
+++ b/src/Functions/factorial.cpp
@@ -15,7 +15,7 @@ namespace ErrorCodes
 template <typename A>
 struct FactorialImpl
 {
-    using ResultType = Int64;
+    using ResultType = UInt64;
     static const constexpr bool allow_decimal = false;
     static const constexpr bool allow_fixed_string = false;
     static const constexpr bool allow_string_integer = false;
@@ -101,7 +101,7 @@ REGISTER_FUNCTION(Factorial)
     factory.registerFunction<FunctionFactorial>(
         {
             R"(
-Computes the factorial of an integer value. It works with any native integer type including UInt(8|16|32|64) and Int(8|16|32|64). The return type is Int64.
+Computes the factorial of an integer value. It works with any native integer type including UInt(8|16|32|64) and Int(8|16|32|64). The return type is UInt64.
 
 The factorial of 0 is 1. Likewise, the factorial() function returns 1 for any negative value. The maximum positive value for the input argument is 20, a value of 21 or greater overflows the range for Int64 and will cause exception throw.
 )",