Fix the issue that functions that rely on tipb::FieldType may produ…

…ce incorrect results (#8483)

close #8482

dbms/src/Flash/Coprocessor/DAGExpressionAnalyzerHelper.cpp

@@ -245,7 +245,7 @@ String DAGExpressionAnalyzerHelper::buildCastFunctionInternal(
 {
     static const String tidb_cast_name = "tidb_cast";
 
-    String result_name = genFuncString(tidb_cast_name, argument_names, {nullptr});
+    String result_name = genFuncString(tidb_cast_name, argument_names, {nullptr}, {&field_type});
     if (actions->getSampleBlock().has(result_name))
         return result_name;
 
@@ -299,7 +299,7 @@ String DAGExpressionAnalyzerHelper::buildSingleParamJsonRelatedFunctions(
     const auto & input_expr = expr.children(0);
     String arg = analyzer->getActions(input_expr, actions);
     const auto & collator = getCollatorFromExpr(expr);
-    String result_name = genFuncString(func_name, {arg}, {collator});
+    String result_name = genFuncString(func_name, {arg}, {collator}, {&input_expr.field_type(), &expr.field_type()});
     if (actions->getSampleBlock().has(result_name))
         return result_name;
 

dbms/src/Flash/Coprocessor/DAGUtils.cpp

@@ -1405,7 +1405,11 @@ SortDescription getSortDescription(
     return order_descr;
 }
 
-String genFuncString(const String & func_name, const Names & argument_names, const TiDB::TiDBCollators & collators)
+String genFuncString(
+    const String & func_name,
+    const Names & argument_names,
+    const TiDB::TiDBCollators & collators,
+    const std::vector<const tipb::FieldType *> & field_types)
 {
     FmtBuffer buf;
     buf.fmtAppend("{}({})_collator", func_name, fmt::join(argument_names.begin(), argument_names.end(), ", "));
@@ -1417,6 +1421,14 @@ String genFuncString(const String & func_name, const Names & argument_names, con
             buf.append("_0");
     }
     buf.append(" ");
+    buf.joinStr(
+        field_types.begin(),
+        field_types.end(),
+        [](const auto & field_type, FmtBuffer & buffer) {
+            if likely (field_type)
+                buffer.fmtAppend("{}|{}", field_type->flag(), field_type->flen());
+        },
+        ", ");
     return buf.toString();
 }
 

dbms/src/Flash/Coprocessor/DAGUtils.h

@@ -65,7 +65,11 @@ DataTypePtr inferDataType4Literal(const tipb::Expr & expr);
 SortDescription getSortDescription(
     const std::vector<NameAndTypePair> & order_columns,
     const google::protobuf::RepeatedPtrField<tipb::ByItem> & by_items);
-String genFuncString(const String & func_name, const Names & argument_names, const TiDB::TiDBCollators & collators);
+String genFuncString(
+    const String & func_name,
+    const Names & argument_names,
+    const TiDB::TiDBCollators & collators,
+    const std::vector<const tipb::FieldType *> & field_types = {});
 
 extern const Int8 VAR_SIZE;
 

tests/fullstack-test/expr/issue_8482.test

@@ -0,0 +1,44 @@
+# Copyright 2023 PingCAP, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+mysql> drop table if exists test.t;
+mysql> create table test.t(b json);
+mysql> alter table test.t set tiflash replica 1;
+mysql> insert into test.t values (true);
+
+func> wait_table test t
+
+mysql> set tidb_allow_mpp=1;set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select b = true from test.t;
++----------+
+| b = true |
++----------+
+|        0 |
++----------+
+
+mysql> set tidb_allow_mpp=1;set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select b = 1 from test.t;
++-------+
+| b = 1 |
++-------+
+|     1 |
++-------+
+
+mysql> set tidb_allow_mpp=1;set tidb_enforce_mpp=1; set tidb_isolation_read_engines='tiflash'; select b = true, b = 1 from test.t;
++----------+-------+
+| b = true | b = 1 |
++----------+-------+
+|        0 |     1 |
++----------+-------+
+
+# Clean up.
+mysql> drop table if exists test.t;