SELECT N'string'

include/m_ctype.h

@@ -85,7 +85,8 @@ enum my_lex_states
   MY_LEX_LONG_COMMENT, MY_LEX_END_LONG_COMMENT, MY_LEX_COLON, 
   MY_LEX_SET_VAR, MY_LEX_USER_END, MY_LEX_HOSTNAME, MY_LEX_SKIP, 
   MY_LEX_USER_VARIABLE_DELIMITER, MY_LEX_SYSTEM_VAR,
-  MY_LEX_IDENT_OR_KEYWORD, MY_LEX_IDENT_OR_HEX, MY_LEX_IDENT_OR_BIN,
+  MY_LEX_IDENT_OR_KEYWORD,
+  MY_LEX_IDENT_OR_HEX, MY_LEX_IDENT_OR_BIN, MY_LEX_IDENT_OR_NCHAR,
   MY_LEX_STRING_OR_DELIMITER
 };
 

mysys/charset.c

@@ -110,6 +110,7 @@ static void init_state_maps(CHARSET_INFO *cs)
   /* Special handling of hex and binary strings */
   state_map[(uchar)'x']= state_map[(uchar)'X']= (uchar) MY_LEX_IDENT_OR_HEX;
   state_map[(uchar)'b']= state_map[(uchar)'b']= (uchar) MY_LEX_IDENT_OR_BIN;
+  state_map[(uchar)'n']= state_map[(uchar)'N']= (uchar) MY_LEX_IDENT_OR_NCHAR;
 
 
 }

sql/sql_lex.cc

@@ -463,6 +463,26 @@ int yylex(void *arg, void *yythd)
 	lex->tok_start=lex->ptr;	// Let tok_start point at next item
       return((int) c);
 
+    case MY_LEX_IDENT_OR_NCHAR:
+      if (yyPeek() != '\'')
+      {					// Found x'hex-number'
+	state= MY_LEX_IDENT;
+	break;
+      }
+      yyGet();				// Skip '
+      while ((c = yyGet()) && (c !='\'')) ;
+      length=(lex->ptr - lex->tok_start);	// Length of hexnum+3
+      if (c != '\'')
+      {
+	return(ABORT_SYM);		// Illegal hex constant
+      }
+      yyGet();				// get_token makes an unget
+      yylval->lex_str=get_token(lex,length);
+      yylval->lex_str.str+=2;		// Skip x'
+      yylval->lex_str.length-=3;	// Don't count x' and last '
+      lex->yytoklen-=3;
+      return (NCHAR_STRING);
+
     case MY_LEX_IDENT_OR_HEX:
       if (yyPeek() == '\'')
       {					// Found x'hex-number'

sql/sql_yacc.yy

@@ -291,6 +291,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token	NATURAL
 %token	NEW_SYM
 %token	NCHAR_SYM
+%token	NCHAR_STRING
 %token	NOT
 %token	NO_SYM
 %token	NULL_SYM
@@ -561,6 +562,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	IDENT TEXT_STRING REAL_NUM FLOAT_NUM NUM LONG_NUM HEX_NUM LEX_HOSTNAME
 	ULONGLONG_NUM field_ident select_alias ident ident_or_text
         UNDERSCORE_CHARSET IDENT_sys TEXT_STRING_sys TEXT_STRING_db
+	NCHAR_STRING
 
 %type <lex_str_ptr>
 	opt_table_alias
@@ -3862,10 +3864,13 @@ text_literal:
 			    thd->charset() : thd->db_charset;
 	  $$ = new Item_string($1.str,$1.length,cs);
 	}
+	| NCHAR_STRING
+	{ $$=  new Item_string($1.str,$1.length,&my_charset_utf8); }
 	| UNDERSCORE_CHARSET TEXT_STRING
 	  { $$ = new Item_string($2.str,$2.length,Lex->charset,Item::COER_IMPLICIT); }
 	| text_literal TEXT_STRING_db
-	  { ((Item_string*) $1)->append($2.str,$2.length); };
+	  { ((Item_string*) $1)->append($2.str,$2.length); }
+	;
 
 text_string:
 	TEXT_STRING_db