fix rewrite bug: replace column with const value

src/share/object/ob_obj_cast.h

@@ -45,6 +45,7 @@ namespace common
 #define CM_SET_MIN_IF_OVERFLOW           (1ULL << 9)
 #define CM_ERROR_ON_SCALE_OVER           (1ULL << 10)
 
+#define CM_TO_COLUMN_CS_LEVEL            (1ULL << 52)
 #define CM_ERROR_FOR_DIVISION_BY_ZERO    (1ULL << 53)
 #define CM_NO_ZERO_IN_DATE               (1ULL << 54) // reserve
 #define CM_NO_ZERO_DATE                  (1ULL << 55)
@@ -99,6 +100,7 @@ typedef uint64_t ObCastMode;
 #define CM_IS_SET_MIN_IF_OVERFLOW(mode)       ((CM_SET_MIN_IF_OVERFLOW & (mode)) != 0)
 #define CM_IS_ERROR_ON_SCALE_OVER(mode)       ((CM_ERROR_ON_SCALE_OVER & (mode)) != 0)
 #define CM_IS_JSON_VALUE(mode)                CM_IS_ERROR_ON_SCALE_OVER(mode)
+#define CM_IS_TO_COLUMN_CS_LEVEL(mode)        ((CM_TO_COLUMN_CS_LEVEL & (mode)) != 0)
 
 struct ObObjCastParams
 {

src/sql/engine/expr/ob_expr_cast.cpp

@@ -294,6 +294,7 @@ int ObExprCast::calc_result_type2(ObExprResType &type,
   ObRawExpr *cast_raw_expr = NULL;
   const sql::ObSQLSessionInfo *session = NULL;
   bool is_explicit_cast = false;
+  bool is_to_column_cs_level = false;
   if (OB_ISNULL(session = type_ctx.get_session()) ||
       OB_ISNULL(cast_raw_expr = get_raw_expr())) {
     ret = OB_ERR_UNEXPECTED;
@@ -310,6 +311,7 @@ int ObExprCast::calc_result_type2(ObExprResType &type,
              "dst", ob_obj_type_str(dst_type.get_type()));
   } else if (FALSE_IT(is_explicit_cast = CM_IS_EXPLICIT_CAST(cast_raw_expr->get_extra()))) {
   // check cast supported in cast_map but not support here.
+  } else if (FALSE_IT(is_to_column_cs_level = CM_IS_TO_COLUMN_CS_LEVEL(cast_raw_expr->get_extra()))) {
   } else if (!check_cast_allowed(type1.get_type(), type1.get_collation_type(),
                                  dst_type.get_type(), dst_type.get_collation_type(),
                                  is_explicit_cast)) {
@@ -355,7 +357,7 @@ int ObExprCast::calc_result_type2(ObExprResType &type,
       type1.set_calc_type(get_calc_cast_type(type1.get_type(), dst_type.get_type()));
       int32_t length = 0;
       if (ob_is_string_or_lob_type(dst_type.get_type()) || ob_is_raw(dst_type.get_type()) || ob_is_json(dst_type.get_type())) {
-        type.set_collation_level(is_explicit_cast
+        type.set_collation_level((is_explicit_cast || is_to_column_cs_level)
                                  ? CS_LEVEL_IMPLICIT
                                  : type1.get_collation_level());
         int32_t len = dst_type.get_length();

src/sql/rewrite/ob_transform_join_elimination.cpp

@@ -1054,22 +1054,16 @@ int ObTransformJoinElimination::do_eliminate_left_outer_join(ObDMLStmt *stmt,
           LOG_WARN("get unexpected null", K(ret));
         } else if (OB_FAIL(ObRawExprUtils::build_null_expr(*ctx_->expr_factory_, to_expr))) {
           LOG_WARN("failed to create new raw expr", K(ret));
-        } else if (OB_FAIL(ObSQLUtils::get_default_cast_mode(true,/* explicit_cast */
+        } else if (OB_FAIL(ObSQLUtils::get_default_cast_mode(false,/* explicit_cast */
                                                              0,    /* result_flag */
-                                                             ctx_->session_info_, cm))) {
+                                                             ctx_->session_info_,
+                                                             cm))) {
           LOG_WARN("fail to get default cast mode", K(ret));
-        } else if (is_mysql_mode() &&
-                   OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_, 
+        } else if (OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_,
                                                             to_expr, 
                                                             from_expr->get_result_type(), 
                                                             cast_expr, ctx_->session_info_,
-                                                            false, cm))) {
-          LOG_WARN("failed to cast expr", K(ret), K(*from_expr), K(*to_expr));
-        } else if (is_oracle_mode() &&
-                   OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_, 
-                                                            to_expr, 
-                                                            from_expr->get_result_type(), 
-                                                            cast_expr, ctx_->session_info_))) {
+                                                            false, cm | CM_TO_COLUMN_CS_LEVEL))) {
           LOG_WARN("failed to cast expr", K(ret), K(*from_expr), K(*to_expr));
         } else if (OB_ISNULL(cast_expr)) {
           ret = OB_ERR_UNEXPECTED;

src/sql/rewrite/ob_transform_left_join_to_anti.cpp

@@ -313,23 +313,16 @@ int ObTransformLeftJoinToAnti::trans_stmt_to_anti(ObDMLStmt *stmt, const JoinedT
       } else if (OB_FAIL(ObRawExprUtils::build_null_expr(*ctx_->expr_factory_,
                                                          to_expr))) {
         LOG_WARN("failed to build null expr", K(ret));
-      } else if (OB_FAIL(ObSQLUtils::get_default_cast_mode(true,/* explicit_cast */
-                                                            0,    /* result_flag */
-                                                            ctx_->session_info_, cm))) {
+      } else if (OB_FAIL(ObSQLUtils::get_default_cast_mode(false,/* explicit_cast */
+                                                           0,    /* result_flag */
+                                                           ctx_->session_info_, cm))) {
         LOG_WARN("fail to get default cast mode", K(ret));
-      } else if (is_mysql_mode() &&
-                  OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_, 
-                                                            to_expr, 
-                                                            from_expr->get_result_type(), 
-                                                            cast_expr, ctx_->session_info_,
-                                                            false, cm))) {
-          LOG_WARN("failed to cast expr", K(ret), K(*from_expr), K(*to_expr));
-        } else if (is_oracle_mode() &&
-                   OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_, 
-                                                            to_expr, 
-                                                            from_expr->get_result_type(), 
-                                                            cast_expr, ctx_->session_info_))) {
-          LOG_WARN("failed to cast expr", K(ret), K(*from_expr), K(*to_expr));
+      } else if (OB_FAIL(ObRawExprUtils::create_cast_expr(*ctx_->expr_factory_,
+                                                          to_expr,
+                                                          from_expr->get_result_type(),
+                                                          cast_expr, ctx_->session_info_,
+                                                          false, cm | CM_TO_COLUMN_CS_LEVEL))) {
+        LOG_WARN("failed to cast expr", K(ret), K(*from_expr), K(*to_expr));
       } else if (OB_ISNULL(to_expr = cast_expr)) {
         ret = OB_ERR_UNEXPECTED;
         LOG_WARN("get unexpected null cast expr", K(ret));