[Bug] Left() string function behaves not identically to the mysql implementation (#6811)

See Fix #6810
2021-10-15 10:17:21 +08:00
parent 05e59f6487
commit 58440b90f0
2 changed files with 8 additions and 0 deletions
--- a/be/src/exprs/string_functions.cpp
+++ b/be/src/exprs/string_functions.cpp
@ -120,6 +120,7 @@ StringVal StringFunctions::substring(FunctionContext* context, const StringVal&
 //    string left(string input, int len)
 // This behaves identically to the mysql implementation.
 StringVal StringFunctions::left(FunctionContext* context, const StringVal& str, const IntVal& len) {
+    if (len.val >= str.len)  return str;
    return substring(context, str, 1, len);
 }