Create Table

Using lex-yacc check create table  in a C program

YACC FILE

Source Code:


%{
#include 
void yyerror(char *);
int yylex();
%}
%token  CREATE TABLE ID REFERENCES CHECK IN PRIMARY KEY DEFAULT DIGIT VARCHAR2 NUMBER INV FOREIGN
%%
program	: CREATE TABLE ID  '(' op  ')'  ';'    {printf("Successful parsing");}
		;

op		:decl   
		|decl ',' op
		;

decl		:dec
		|pk
		|fk
		;
dec		: ID  datatype   '('  DIGIT ')'   check default  
		;
datatype	:VARCHAR2
		|NUMBER
		; 
check 		: CHECK '(' ID IN '('  id  ')'   ')'
		|
		;
id		: INV ID INV ',' id
		| INV ID INV
		;
default 	:DEFAULT DIGIT
		|
		;
	
fk		:  FOREIGN KEY '(' ID ')'  REFERENCES  ID  '('   ID   ')'	
		
		;
pk		: PRIMARY KEY '('   ID  ')' 
		
		;
	
%%
void yyerror(char *s)
{
printf("Error %s",s);
}
int main()
{
yyparse();
return 0;
}


LEX FILE

Source Code:

%{
#include "y.tab.h"
int yywrap();
void yyerror(char *);
%}
%%
"create"  {return CREATE;}
"foreign"  {return FOREIGN;}
"table"  {return TABLE;}
"references"  {return REFERENCES;}
"check"  {return CHECK;}
"in"  {return IN;}
"primary"  {return PRIMARY;}
"key"  {return KEY;}
"default"  {return DEFAULT;}
"varchar2"  {return VARCHAR2;}
"number"  {return NUMBER;}
"'"  	{return INV;}
[();,] {return *yytext;}
[0-9]+   {return DIGIT;}
[a-zA-Z][a-zA-Z0-9]* {return ID;}
[ \t\n]+ ;
.   {printf("\n\n Error");}


%%
int yywrap()
{
return 1;
}


INPUT :


create table student
(eid number(10),
ename varchar2(10),
primary key(eid),
primary key (ename),
foreign key (ename) references employee(ename)
);

OUTPUT :

[cmasa1@localhost ~]$ yacc -d create.y
[cmasa1@localhost ~]$ lex create.l
[cmasa1@localhost ~]$ cc lex.yy.c y.tab.c -o abc
[cmasa1@localhost ~]$ ./abc