truncate should always be treated as warning in cast decimal as decimal

Signed-off-by: xufei <[email protected]>
pingcap · Apr 25, 2023 · 20a86ec · 20a86ec
1 parent f7c6c60
commit 20a86ec
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/dbms/src/Functions/FunctionsTiDBConversion.h b/dbms/src/Functions/FunctionsTiDBConversion.h
@@ -951,8 +951,8 @@ struct TiDBConvertToDecimal
         }
         else if (v_scale > scale)
         {
-            context.getDAGContext()->handleTruncateError("cast decimal as decimal");
             const bool need_to_round = ((value < 0 ? -value : value) % scale_mul) >= (scale_mul / 2);
+            auto old_value = value;
             value /= scale_mul;
             if (need_to_round)
             {
@@ -961,6 +961,8 @@ struct TiDBConvertToDecimal
                 else
                     ++value;
             }
+            if (old_value != value * scale_mul)
+                context.getDAGContext()->appendWarning("Truncate in cast decimal as decimal");
         }
         else
         {

diff --git a/dbms/src/Functions/tests/gtest_tidb_conversion.cpp b/dbms/src/Functions/tests/gtest_tidb_conversion.cpp
@@ -1308,6 +1308,22 @@ try
 }
 CATCH
 
+TEST_F(TestTidbConversion, truncateInCastDecimalAsDecimal)
+try
+{
+    DAGContext * dag_context = context->getDAGContext();
+    UInt64 ori_flags = dag_context->getFlags();
+    dag_context->addFlag(TiDBSQLFlags::IN_INSERT_STMT | TiDBSQLFlags::IN_UPDATE_OR_DELETE_STMT);
+    dag_context->clearWarnings();
+
+    ASSERT_COLUMN_EQ(createColumn<Decimal32>(std::make_tuple(5, 2), {"1.23", "1.56", "1.01", "1.00", "-1.23", "-1.56", "-1.01", "-1.00"}),
+                     executeFunction(func_name, {createColumn<Decimal32>(std::make_tuple(5, 4), {"1.2300", "1.5600", "1.0056", "1.0023", "-1.2300", "-1.5600", "-1.0056", "-1.0023"}), createCastTypeConstColumn("Decimal(5,2)")}));
+    ASSERT_EQ(dag_context->getWarningCount(), 4);
+    dag_context->setFlags(ori_flags);
+    dag_context->clearWarnings();
+}
+CATCH
+
 TEST_F(TestTidbConversion, castDecimalAsDecimalWithRound)
 try
 {