diff --git a/src/sql/parser/sqlite3_parser.cpp b/src/sql/parser/sqlite3_parser.cpp
index b98d0107..b05ec74a 100644
--- a/src/sql/parser/sqlite3_parser.cpp
+++ b/src/sql/parser/sqlite3_parser.cpp
@@ -2525,7 +2525,7 @@ namespace  sqlb { namespace parser  {
 
   case 180: // optional_sort_order: %empty
 #line 533 "sqlite3_parser.yy"
-                                                { yylhs.value.as < std::string > () = ""; }
+                                                { }
 #line 2530 "sqlite3_parser.cpp"
     break;
 
@@ -2555,7 +2555,7 @@ namespace  sqlb { namespace parser  {
 
   case 185: // optional_where: %empty
 #line 548 "sqlite3_parser.yy"
-                                                { yylhs.value.as < std::string > () = ""; }
+                                                { }
 #line 2560 "sqlite3_parser.cpp"
     break;
 
@@ -2626,13 +2626,13 @@ namespace  sqlb { namespace parser  {
 
   case 194: // optional_exprlist_with_paren: %empty
 #line 593 "sqlite3_parser.yy"
-                                                { yylhs.value.as < std::string > () = {}; }
+                                                { }
 #line 2631 "sqlite3_parser.cpp"
     break;
 
   case 195: // optional_exprlist_with_paren: "(" ")"
 #line 594 "sqlite3_parser.yy"
-                                                { yylhs.value.as < std::string > () = {}; }
+                                                { }
 #line 2637 "sqlite3_parser.cpp"
     break;
 
@@ -2702,7 +2702,7 @@ namespace  sqlb { namespace parser  {
 
   case 206: // optional_tableoptions_list: %empty
 #line 628 "sqlite3_parser.yy"
-                                                        {}
+                                                        { }
 #line 2707 "sqlite3_parser.cpp"
     break;
 
@@ -2714,7 +2714,7 @@ namespace  sqlb { namespace parser  {
 
   case 208: // optional_conflictclause: %empty
 #line 633 "sqlite3_parser.yy"
-                                                        { yylhs.value.as < std::string > () = ""; }
+                                                        { }
 #line 2719 "sqlite3_parser.cpp"
     break;
 
@@ -2750,7 +2750,7 @@ namespace  sqlb { namespace parser  {
 
   case 214: // optional_typename: %empty
 #line 642 "sqlite3_parser.yy"
-                                                { yylhs.value.as < std::string > () = ""; }
+                                                { }
 #line 2755 "sqlite3_parser.cpp"
     break;
 
@@ -3035,7 +3035,7 @@ namespace  sqlb { namespace parser  {
 
   case 242: // optional_constraintname: %empty
 #line 808 "sqlite3_parser.yy"
-                                                        { yylhs.value.as < std::string > () = ""; }
+                                                        { }
 #line 3040 "sqlite3_parser.cpp"
     break;
 
@@ -3065,7 +3065,7 @@ namespace  sqlb { namespace parser  {
 
   case 247: // optional_columnid_with_paren_list: %empty
 #line 819 "sqlite3_parser.yy"
-                                                        { yylhs.value.as < sqlb::StringVector > () = sqlb::StringVector(); }
+                                                        { }
 #line 3070 "sqlite3_parser.cpp"
     break;
 
@@ -3185,7 +3185,7 @@ namespace  sqlb { namespace parser  {
 
   case 267: // optional_fk_clause: %empty
 #line 848 "sqlite3_parser.yy"
-                                                                        { yylhs.value.as < std::string > () = ""; }
+                                                                        { }
 #line 3190 "sqlite3_parser.cpp"
     break;
 
@@ -3340,7 +3340,7 @@ namespace  sqlb { namespace parser  {
 
   case 289: // optional_tableconstraint_list: %empty
 #line 902 "sqlite3_parser.yy"
-                                                        { yylhs.value.as < sqlb::ConstraintVector > () = {}; }
+                                                        { }
 #line 3345 "sqlite3_parser.cpp"
     break;
 
diff --git a/src/sql/parser/sqlite3_parser.yy b/src/sql/parser/sqlite3_parser.yy
index 914fc937..26521f96 100644
--- a/src/sql/parser/sqlite3_parser.yy
+++ b/src/sql/parser/sqlite3_parser.yy
@@ -530,7 +530,7 @@ optional_if_not_exists:
 	;
 
 optional_sort_order:
-	%empty					{ $$ = ""; }
+	%empty					{ }
 	| ASC					{ $$ = "ASC"; }
 	| DESC					{ $$ = "DESC"; }
 	;
@@ -545,7 +545,7 @@ optional_unique:
 	;
 
 optional_where:
-	%empty					{ $$ = ""; }
+	%empty					{ }
 	| WHERE expr				{ $$ = $2; }
 	;
 
@@ -590,8 +590,8 @@ createindex_stmt:
  */
 
 optional_exprlist_with_paren:
-	%empty					{ $$ = {}; }
-	| "(" ")"				{ $$ = {}; }
+	%empty					{ }
+	| "(" ")"				{ }
 	| "(" exprlist_expr ")"			{ $$ = $2; }
 	;
 
@@ -625,12 +625,12 @@ tableoptions_list:
 	;
 
 optional_tableoptions_list:
-	%empty						{}
+	%empty						{ }
 	| tableoptions_list				{ $$ = $1; }
 	;
 
 optional_conflictclause:
-	%empty						{ $$ = ""; }
+	%empty						{ }
 	| ON CONFLICT ROLLBACK				{ $$ = $3; }
 	| ON CONFLICT ABORT				{ $$ = $3; }
 	| ON CONFLICT FAIL				{ $$ = $3; }
@@ -639,7 +639,7 @@ optional_conflictclause:
 	;
 
 optional_typename:
-	%empty					{ $$ = ""; }
+	%empty					{ }
 	| type_name				{ $$ = $1; }
 	;
 
@@ -805,7 +805,7 @@ columndef_list:
 	;
 
 optional_constraintname:
-	%empty						{ $$ = ""; }
+	%empty						{ }
 	| CONSTRAINT id					{ $$ = $2; }
 	| CONSTRAINT STRINGLITERAL			{ $$ = $2; }
 	;
@@ -816,7 +816,7 @@ columnid_list:
 	;
 
 optional_columnid_with_paren_list:
-	%empty						{ $$ = sqlb::StringVector(); }
+	%empty						{ }
 	| "(" columnid_list ")"				{ $$ = $2; }
 	;
 
@@ -845,7 +845,7 @@ fk_clause_part_list:
 	;
 
 optional_fk_clause:
-	%empty								{ $$ = ""; }
+	%empty								{ }
 	| fk_clause_part_list						{ $$ = $1; }
 	| fk_clause_part_list DEFERRABLE INITIALLY DEFERRED		{ $$ = $1 + " " + $2 + " " + $3 + " " + $4; }
 	| fk_clause_part_list DEFERRABLE INITIALLY IMMEDIATE		{ $$ = $1 + " " + $2 + " " + $3 + " " + $4; }
@@ -899,7 +899,7 @@ tableconstraint_list:
 	;
 
 optional_tableconstraint_list:
-	%empty						{ $$ = {}; }
+	%empty						{ }
 	| "," tableconstraint_list			{ $$ = $2; }
 	;