fix left and substring with len -1

apache · Jun 3, 2024 · 96a9d61 · 96a9d61
1 parent 4dcda6a
commit 96a9d61
Show file tree

Hide file tree

Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/...src/test/scala/org/apache/gluten/execution/GlutenClickHouseTPCHSaltNullParquetSuite.scala b/...src/test/scala/org/apache/gluten/execution/GlutenClickHouseTPCHSaltNullParquetSuite.scala
@@ -2563,5 +2563,18 @@ class GlutenClickHouseTPCHSaltNullParquetSuite extends GlutenClickHouseTPCHAbstr
     compareResultsAgainstVanillaSpark(select_sql, true, { _ => })
     spark.sql("drop table test_tbl_5896")
   }
+
+  test("test left with len -1") {
+    val tbl_create_sql =
+      "create table test_left(col string) using parquet"
+    val tbl_insert_sql =
+      "insert into test_left values('test1'), ('test2')"
+    spark.sql(tbl_create_sql)
+    spark.sql(tbl_insert_sql)
+    compareResultsAgainstVanillaSpark("select left(col, -1) from test_left", true, { _ => })
+    compareResultsAgainstVanillaSpark("select left(col, -2) from test_left", true, { _ => })
+    compareResultsAgainstVanillaSpark("select substring(col, 0, -1) from test_left", true, { _ => })
+    spark.sql("drop table test_left")
+  }
 }
 // scalastyle:on line.size.limit
diff --git a/cpp-ch/local-engine/Parser/scalar_function_parser/substring.cpp b/cpp-ch/local-engine/Parser/scalar_function_parser/substring.cpp
@@ -59,7 +59,9 @@ class FunctionParserSubstring : public FunctionParser
         const auto * const_one_node = addColumnToActionsDAG(actions_dag, index_type, 1);
         const auto * equals_zero_node = toFunctionNode(actions_dag, "equals", {index_arg, const_zero_node});
         const auto * if_node = toFunctionNode(actions_dag, "if", {equals_zero_node, const_one_node, index_arg});
-        const auto * substring_func_node = toFunctionNode(actions_dag, "substringUTF8", {str_arg, if_node, length_arg});
+        const auto * less_zero_node = toFunctionNode(actions_dag, "less", {length_arg, const_zero_node});
+        const auto * if_len_node = toFunctionNode(actions_dag, "if", {less_zero_node, const_zero_node, length_arg});
+        const auto * substring_func_node = toFunctionNode(actions_dag, "substringUTF8", {str_arg, if_node, if_len_node});
         return convertNodeTypeIfNeeded(substrait_func, substring_func_node, actions_dag);
     }
 protected: