refine decimal exception message (#3375)

pingcap · Nov 4, 2021 · 89c472f · 89c472f
1 parent 5d487be
commit 89c472f
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Showing 2 changed files with 33 additions and 15 deletions.
diff --git a/dbms/src/DataTypes/DataTypeDecimal.cpp b/dbms/src/DataTypes/DataTypeDecimal.cpp
@@ -11,7 +11,6 @@
 
 namespace DB
 {
-
 template <typename T>
 std::string DataTypeDecimal<T>::getName() const
 {
@@ -183,15 +182,20 @@ static DataTypePtr create(const ASTPtr & arguments)
     const ASTLiteral * arg0 = typeid_cast<const ASTLiteral *>(arguments->children[0].get());
     if (!arg0 || arg0->value.getType() != Field::Types::UInt64 || arg0->value.get<UInt64>() == 0)
         throw Exception(
-            "Decimal data type family must have a number (positive integer) as its argument", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
+            "Decimal data type family must have a number (positive integer) as its argument",
+            ErrorCodes::ARGUMENT_OUT_OF_BOUND);
     const ASTLiteral * arg1 = typeid_cast<const ASTLiteral *>(arguments->children[1].get());
     if (!arg1 || arg1->value.getType() != Field::Types::UInt64)
         throw Exception(
-            "Decimal data type family must have a number (positive integer) as its argument", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
+            "Decimal data type family must have a number (positive integer) as its argument",
+            ErrorCodes::ARGUMENT_OUT_OF_BOUND);
     return createDecimal(arg0->value.get<UInt64>(), arg1->value.get<UInt64>());
 }
 
-void registerDataTypeDecimal(DataTypeFactory & factory) { factory.registerDataType("Decimal", create, DataTypeFactory::CaseInsensitive); }
+void registerDataTypeDecimal(DataTypeFactory & factory)
+{
+    factory.registerDataType("Decimal", create, DataTypeFactory::CaseInsensitive);
+}
 
 template class DataTypeDecimal<Decimal32>;
 template class DataTypeDecimal<Decimal64>;

diff --git a/dbms/src/DataTypes/DataTypeDecimal.h b/dbms/src/DataTypes/DataTypeDecimal.h
@@ -5,6 +5,7 @@
 #include <DataTypes/DataTypeFactory.h>
 #include <DataTypes/IDataType.h>
 #include <IO/WriteHelpers.h>
+#include <fmt/core.h>
 
 
 namespace DB
@@ -22,7 +23,7 @@ extern const int ARGUMENT_OUT_OF_BOUND;
 // Int256 65
 
 template <typename T>
-class DataTypeDecimal : public IDataType
+class DataTypeDecimal final : public IDataType
 {
     static_assert(IsDecimal<T>);
 
@@ -52,7 +53,20 @@ class DataTypeDecimal : public IDataType
     {
         if (precision > decimal_max_prec || scale > precision || scale > decimal_max_scale)
         {
-            throw Exception(getName() + "is out of bound", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
+            std::string msg = getName() + "is out of bound";
+            if (precision > decimal_max_prec)
+            {
+                msg = fmt::format("{}, precision {} is greater than maximum value {}", msg, precision, decimal_max_prec);
+            }
+            else if (scale > precision)
+            {
+                msg = fmt::format("{}, scale {} is greater than precision {}", msg, scale, precision);
+            }
+            else
+            {
+                msg = fmt::format("{}, scale {} is greater than maximum value {}", msg, scale, decimal_max_scale);
+            }
+            throw Exception(msg, ErrorCodes::ARGUMENT_OUT_OF_BOUND);
         }
     }
 
@@ -119,7 +133,7 @@ class DataTypeDecimal : public IDataType
     void serializeTextJSON(const IColumn & column, size_t row_num, WriteBuffer & ostr, const FormatSettingsJSON &) const override;
 
     void serializeTextCSV(const IColumn & column, size_t row_num, WriteBuffer & ostr) const override;
-    void deserializeTextCSV(IColumn & column, ReadBuffer & istr, const char delimiter) const override;
+    void deserializeTextCSV(IColumn & column, ReadBuffer & istr, char delimiter) const override;
 
     void readText(T & x, ReadBuffer & istr) const;
 
@@ -216,26 +230,26 @@ typename std::enable_if_t<(sizeof(T) < sizeof(U)), const DataTypeDecimal<U>> dec
 
 inline PrecType getDecimalPrecision(const IDataType & data_type, PrecType default_value)
 {
-    if (auto * decimal_type = checkDecimal<Decimal32>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal32>(data_type))
         return decimal_type->getPrec();
-    if (auto * decimal_type = checkDecimal<Decimal64>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal64>(data_type))
         return decimal_type->getPrec();
-    if (auto * decimal_type = checkDecimal<Decimal128>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal128>(data_type))
         return decimal_type->getPrec();
-    if (auto * decimal_type = checkDecimal<Decimal256>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal256>(data_type))
         return decimal_type->getPrec();
     return default_value;
 }
 
 inline ScaleType getDecimalScale(const IDataType & data_type, ScaleType default_value)
 {
-    if (auto * decimal_type = checkDecimal<Decimal32>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal32>(data_type))
         return decimal_type->getScale();
-    if (auto * decimal_type = checkDecimal<Decimal64>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal64>(data_type))
         return decimal_type->getScale();
-    if (auto * decimal_type = checkDecimal<Decimal128>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal128>(data_type))
         return decimal_type->getScale();
-    if (auto * decimal_type = checkDecimal<Decimal256>(data_type))
+    if (const auto * decimal_type = checkDecimal<Decimal256>(data_type))
         return decimal_type->getScale();
     return default_value;
 }