refactored grammar. now includes where clause

src/build_and_run.sh

@@ -4,5 +4,5 @@ make clean
 make tests
 ./bin/tests
 
-make execution
-./bin/sql_execution "SELECT col1, col2 FROM table GROUP BY col1;"
+# make execution
+# ./bin/sql_execution "SELECT col1, col2 FROM table GROUP BY col1;"

src/lex_lexer.l

@@ -32,6 +32,18 @@ SELECT	TOK(SELECT)
 FROM	TOK(FROM)
 GROUP	TOK(GROUP)
 BY		TOK(BY)
+WHERE	TOK(WHERE)
+NOT		TOK(NOT)
+AND		TOK(AND)
+OR		TOK(OR)
+
+
+"="		|
+"<>" 	|
+"<"		|
+">"		|
+"<="	|
+">="	TOK(COMPARISON)
 
 [-+*/(),.;]	TOK(yytext[0])
 
@@ -40,6 +52,12 @@ BY	TOK(BY)
 "."[0-9]*	TOK(INTNUM)
 
 [A-Za-z][A-Za-z0-9_]* {
+	yylval->sval = strdup(yytext);
+	return NAME;
+}
+
+
+'[^'\n]*' {
 	yylval->sval = strdup(yytext);
 	return STRING;
 }

src/lex_parser.y

@@ -48,73 +48,131 @@ typedef void* yyscan_t;
 	List<Expression*>* explist;
 }
 
-%token SELECT FROM GROUP BY INTNUM
-%token <sval> STRING
+%token SELECT FROM GROUP BY WHERE NOT AND OR
+%token INTNUM COMPARISON STRING
+%token <sval> NAME
 
 %type <statement> statement
 %type <select_statement> select_statement
-%type <table> from_clause
-%type <slist> string_list
-%type <explist> expr_list group_clause
+%type <sval> column_name table_name
+%type <table> from_clause table_exp
 %type <expr> expr;
+%type <slist> table_ref_commalist
+%type <explist> expr_list group_clause
 %%
 
 
 input: 
-	statement opt_semicolon { *statement = $1; };
-
-
-opt_semicolon:
-	';' | ;
-
+		statement opt_semicolon { *statement = $1; }
+	;
 
 statement:
 		select_statement { $$ = $1; }
-	|  { $$ = NULL; };
+	|	/* empty */ { $$ = NULL; }
+	;
+
+
 
 
 select_statement:
-	SELECT expr_list from_clause group_clause
+		SELECT expr_list from_clause where_clause group_clause
 		{ 
 			SelectStatement* s = new SelectStatement();
 			s->_select_list = $2;
 			s->_from_table = $3;
-			s->_group_by = $4;
+			s->_group_by = $5;
 			$$ = s;
-		};
+		}
+		;
 
 
-expr_list: 
-	expr { $$ = new List<Expression*>($1); }
-	| expr_list ',' expr { $1->push_back($3); $$ = $1; };
-
-
-expr:
-	STRING { $$ = new Expression($1); }
-	| STRING '(' STRING ')' { $$ = new Expression($3, $1); };
-
 
 from_clause:
-	FROM string_list
-		{ 
-			TableRef* t = new TableRef(eTableName);
-			t->_table_names = $2;
-			$$ = t;
-		}
-	| FROM '(' select_statement ')'
-		{
-			TableRef* t = new TableRef(eTableSelect);
-			t->_stmt = $3;
-			$$ = t;
-		};
+		FROM table_exp { $$ = $2; }
+	;
 
+where_clause:
+		WHERE search_condition
+	|	/* empty */
+	;
 
 group_clause:
 		GROUP BY expr_list { $$ = $3; }
-	| { $$ = NULL; };
+	|	/* empty */ { $$ = NULL; }
+	;
 
-string_list:
-	STRING { $$ = new List<char*>($1); }
-	| string_list ',' STRING { $1->push_back($3); $$ = $1; }
 
+
+table_exp:
+		table_ref_commalist { 
+			TableRef* t = new TableRef(eTableName);
+			t->_table_names = $1;
+			$$ = t;
+		}
+	|	'(' select_statement ')' {
+			TableRef* t = new TableRef(eTableSelect);
+			t->_stmt = $2;
+			$$ = t;
+		}
+	;
+
+
+search_condition:
+		predicate
+	;
+
+predicate:
+		comparison_predicate
+	;
+
+comparison_predicate:
+		scalar_exp COMPARISON scalar_exp
+	;
+
+
+expr:
+		column_name { $$ = new Expression($1); }
+	|	NAME '(' column_name ')' { $$ = new Expression($3, $1); }
+	;
+
+
+
+/* Lists */
+expr_list: 
+		expr { $$ = new List<Expression*>($1); }
+	|	expr_list ',' expr { $1->push_back($3); $$ = $1; }
+	;
+
+
+// TODO: add table_ref to include names and select queries
+table_ref_commalist:
+		table_name { $$ = new List<char*>($1); }
+	|	table_ref_commalist ',' table_name { $1->push_back($3); $$ = $1; }
+	;
+/* / Lists */
+
+
+column_name:
+		NAME
+	;
+
+table_name:
+		NAME
+	|	NAME '.' NAME
+	;
+
+literal:
+		STRING
+	|	INTNUM
+	;
+
+scalar_exp:
+		column_name
+	|	literal
+	;
+
+opt_semicolon:
+		';' 
+	|	/* empty */
+	;
 %%

src/lib/Expression.h

@@ -1,11 +1,12 @@
 #ifndef __EXPRESSION_H__
 #define __EXPRESSION_H__
 
+#include <cstdlib>
 
 
 class Expression {
 public:
-	Expression(char* name) : name(name) {};
+	Expression(char* name) : name(name), func_name(NULL) {};
 	Expression(char* name, char* func_name) : name(name), func_name(func_name) {};
 
 	char* name;

src/sql_tests.cpp

@@ -17,7 +17,7 @@ void SelectTest1() {
 	printf("Test: SelectTest1... ");
 	fflush(stdout);
 
-	const char* sql = "SELECT age, name, address from table;";
+	const char* sql = "SELECT age, name, address from table WHERE age > 12.5;";
 	Statement* stmt = SQLParser::parseSQL(sql);
 	ASSERT(stmt != NULL);
 	ASSERT(stmt->_type == eSelect);