[CP] Fix json cast (issue/41928694 & issue/41985147)

src/sql/engine/expr/ob_expr_ifnull.cpp

@@ -40,7 +40,7 @@ int ObExprIfNull::calc_result_type2(
     LOG_WARN("session is NULL", K(ret));
   } else if (OB_FAIL(ObExprPromotionUtil::get_nvl_type(type, type1, type2))) {
     LOG_WARN("failed to get nvl type", K(ret));
-  } else if (ob_is_string_type(type.get_type())) {
+  } else if (ob_is_string_type(type.get_type()) || ob_is_json_tc(type.get_type())) {
     ObCollationLevel res_cs_level = CS_LEVEL_INVALID;
     ObCollationType res_cs_type = CS_TYPE_INVALID;
     if (OB_FAIL(ObCharset::aggregate_collation(type1.get_collation_level(),

src/sql/engine/expr/ob_expr_relational_cmp_type.map

@@ -1779,7 +1779,7 @@ static ObObjType RELATIONAL_CMP_TYPE[ObMaxType][ObMaxType] =
     ObVarcharType,          /* ObNCharType */
     ObNullType,         /* ObURowIDType */
     ObNullType,         /* ObLobType */
-    ObMaxType,       /* ObJsonType */
+    ObNumberType,       /* ObJsonType */
   },
   /*EnumInnerType*/
   {
@@ -2480,7 +2480,7 @@ static ObObjType RELATIONAL_CMP_TYPE[ObMaxType][ObMaxType] =
     ObJsonType,        /*LongTextType*/
     ObJsonType,      /*BitType*/
     ObMaxType,     /* EnumType  */
-    ObMaxType,     /* SetType  */
+    ObNumberType,     /* SetType  */
     ObMaxType,     /* EnumInnerType  */
     ObMaxType,     /* SetInnerType  */
     ObTimestampTZType,    /* ObTimestampTZType */