fix: format throw data truncated error (#5272)

dbms/src/Functions/FunctionsString.cpp

@@ -4584,7 +4584,9 @@ class FormatImpl : public IFunction
             using NumberFieldType = typename NumberType::FieldType;
             using NumberColVec = std::conditional_t<IsDecimal<NumberFieldType>, ColumnDecimal<NumberFieldType>, ColumnVector<NumberFieldType>>;
             const auto * number_raw = block.getByPosition(arguments[0]).column.get();
+
             TiDBDecimalRoundInfo info{number_type, number_type};
+            info.output_prec = info.output_prec < 65 ? info.output_prec + 1 : 65;
 
             return getPrecisionType(precision_base_type, [&](const auto & precision_type, bool) {
                 using PrecisionType = std::decay_t<decltype(precision_type)>;
@@ -4734,10 +4736,11 @@ class FormatImpl : public IFunction
     static void format(
         T number,
         size_t max_num_decimals,
-        const TiDBDecimalRoundInfo & info,
+        TiDBDecimalRoundInfo & info,
         ColumnString::Chars_t & res_data,
         ColumnString::Offsets & res_offsets)
     {
+        info.output_scale = std::min(max_num_decimals, static_cast<size_t>(info.input_scale));
         auto round_number = round(number, max_num_decimals, info);
         std::string round_number_str = number2Str(round_number, info);
         std::string buffer = Format::apply(round_number_str, max_num_decimals);

dbms/src/Functions/tests/gtest_strings_format.cpp

@@ -34,7 +34,7 @@ class StringFormat : public DB::tests::FunctionTest
         using FieldType = DecimalField<Decimal>;
         using NullableDecimal = Nullable<Decimal>;
         ASSERT_COLUMN_EQ(
-            createColumn<Nullable<String>>({"0.0000", "-0.0120", "0.0120", "12,332.1000", "12,332", "12,332", "12,332.300000000000000000000000000000", "-12,332.30000", "-1,000.0", "-333.33", {}}),
+            createColumn<Nullable<String>>({"0.0000", "-0.0120", "0.0120", "12,332.1000", "12,332", "12,332", "12,332.300000000000000000000000000000", "-12,332.30000", "-1,000.0", "-333.33", {}, "99,999.9999000000", "100,000.000", "100,000"}),
             executeFunction(
                 func_name,
                 createColumn<NullableDecimal>(
@@ -49,8 +49,11 @@ class StringFormat : public DB::tests::FunctionTest
                      FieldType(static_cast<Native>(-123323000), 4),
                      FieldType(static_cast<Native>(-9999999), 4),
                      FieldType(static_cast<Native>(-3333330), 4),
-                     FieldType(static_cast<Native>(0), 0)}),
-                createColumn<Nullable<Int64>>({4, 4, 4, 4, 0, -1, 31, 5, 1, 2, {}})));
+                     FieldType(static_cast<Native>(0), 0),
+                     FieldType(static_cast<Native>(999999999), 4),
+                     FieldType(static_cast<Native>(999999999), 4),
+                     FieldType(static_cast<Native>(999999999), 4)}),
+                createColumn<Nullable<Int64>>({4, 4, 4, 4, 0, -1, 31, 5, 1, 2, {}, 10, 3, -5})));
         ASSERT_COLUMN_EQ(
             createColumn<Nullable<String>>({"12,332.100", "-12,332.300", "-1,000.000", "-333.333"}),
             executeFunction(
@@ -72,7 +75,7 @@ class StringFormat : public DB::tests::FunctionTest
                     FieldType(static_cast<Native>(-9999999), 4)),
                 createColumn<Nullable<Int32>>({4, 0, -1, 31, 5, 1, 2})));
         ASSERT_COLUMN_EQ(
-            createConstColumn<Nullable<String>>(1, "-1,000.000"),
+            createConstColumn<String>(1, "-1,000.000"),
             executeFunction(
                 func_name,
                 createConstColumn<NullableDecimal>(
@@ -115,7 +118,7 @@ class StringFormat : public DB::tests::FunctionTest
                     FieldType(static_cast<Native>(-9999999), 4)),
                 createColumn<Nullable<UInt32>>({4, 0, 31, 5, 1, 2})));
         ASSERT_COLUMN_EQ(
-            createConstColumn<Nullable<String>>(1, "-1,000.000"),
+            createConstColumn<String>(1, "-1,000.000"),
             executeFunction(
                 func_name,
                 createConstColumn<NullableDecimal>(

tests/fullstack-test/expr/format.test

@@ -44,3 +44,52 @@ int_val
 1,234.000
 
 mysql> drop table if exists test.t
+
+mysql> create table test.t(id int, value decimal(65,4))
+mysql> alter table test.t set tiflash replica 1
+mysql> insert into test.t values(1,9999999999999999999999999999999999999999999999999999999999999.9999)
+
+func> wait_table test t
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,-3) as result from test.t
+result
+10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,0) as result from test.t
+result
+10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,3) as result from test.t
+result
+10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.000
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,10) as result from test.t
+result
+9,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999.9999000000
+
+
+mysql> drop table if exists test.t
+
+mysql> create table test.t(id int, value decimal(7,4))
+mysql> alter table test.t set tiflash replica 1
+mysql> insert into test.t values(1,999.9999)
+
+func> wait_table test t
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,-2) as result from test.t
+result
+1,000
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,0) as result from test.t
+result
+1,000
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,2) as result from test.t
+result
+1,000.00
+
+mysql> set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select format(value,10) as result from test.t
+result
+999.9999000000
+
+mysql> drop table if exists test.t