Adds support for date literals (#174)

Author: klauck

src/parser/bison_parser.cpp

@@ -1,8 +1,8 @@
-/* A Bison parser, made by GNU Bison 3.7.4.  */
+/* A Bison parser, made by GNU Bison 3.7.6.  */
 
 /* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2020 Free Software Foundation,
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2021 Free Software Foundation,
    Inc.
 
    This program is free software: you can redistribute it and/or modify
@@ -16,7 +16,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* As a special exception, you may create a larger work that contains
    part or all of the Bison parser skeleton and distribute that work

src/parser/bison_parser.h

@@ -209,7 +209,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %type <table>		    join_clause table_ref_name_no_alias
 %type <expr> 		    expr operand scalar_expr unary_expr binary_expr logic_expr exists_expr extract_expr cast_expr
 %type <expr>		    function_expr between_expr expr_alias param_expr
-%type <expr> 		    column_name literal int_literal num_literal string_literal bool_literal
+%type <expr> 		    column_name literal int_literal num_literal string_literal bool_literal date_literal
 %type <expr> 		    comp_expr opt_where join_condition opt_having case_expr case_list in_expr hint
 %type <expr> 		    array_expr array_index null_literal
 %type <limit>		    opt_limit opt_top
@@ -1031,6 +1031,7 @@ literal:
 	|	bool_literal
 	|	num_literal
 	|	null_literal
+	|	date_literal
 	|	param_expr
 	;
 
@@ -1056,6 +1057,19 @@ null_literal:
 	    	NULL { $$ = Expr::makeNullLiteral(); }
 	;
 
+date_literal:
+		DATE STRING {
+			int day{0}, month{0}, year{0}, chars_parsed{0};
+			// If the whole string is parsed, chars_parsed points to the terminating null byte after the last character
+			if (sscanf($2, "%4d-%2d-%2d%n", &day, &month, &year, &chars_parsed) != 3 || $2[chars_parsed] != 0) {
+				free($2);
+				yyerror(&yyloc, result, scanner, "Found incorrect date format. Expected format: YYYY-MM-DD");
+				YYERROR;
+			}
+			$$ = Expr::makeDateLiteral($2);
+		}
+	;
+
 param_expr:
 		'?' {
 			$$ = Expr::makeParameter(yylloc.total_column);

src/parser/bison_parser.y

@@ -134,6 +134,12 @@ Expr* Expr::makeNullLiteral() {
     return e;
 }
 
+Expr* Expr::makeDateLiteral(char* string) {
+    Expr* e = new Expr(kExprLiteralDate);
+    e->name = string;
+    return e;
+}
+
 Expr* Expr::makeColumnRef(char* name) {
     Expr* e = new Expr(kExprColumnRef);
     e->name = name;

src/sql/Expr.cpp

@@ -18,6 +18,7 @@ enum ExprType {
     kExprLiteralString,
     kExprLiteralInt,
     kExprLiteralNull,
+    kExprLiteralDate,
     kExprStar,
     kExprParameter,
     kExprColumnRef,
@@ -150,6 +151,8 @@ struct Expr {
 
     static Expr* makeNullLiteral();
 
+    static Expr* makeDateLiteral(char* val);
+
     static Expr* makeColumnRef(char* name);
 
     static Expr* makeColumnRef(char* table, char* name);

src/sql/Expr.h

@@ -121,6 +121,12 @@ namespace hsql {
     case kExprLiteralString:
       inprint(expr->name, numIndent);
       break;
+    case kExprLiteralDate:
+      inprint(expr->name, numIndent);
+      break;
+    case kExprLiteralNull:
+      inprint("NULL", numIndent);
+      break;
     case kExprFunctionRef:
       inprint(expr->name, numIndent);
       for (Expr* e : *expr->exprList) printExpression(e, numIndent + 1);

src/util/sqlhelper.cpp

@@ -21,4 +21,9 @@
 !WITH a AS (SELECT ) b AS (SELECT ) SELECT 1; # Missing comma between WITH descriptions
 !BEGIN TRANSACTION transName; # Transaction naming is currently not supported
 !SELECT -9223372036854775809; # Out of int64_t range
-!SELECT 9223372036854775808; # Out of int64_t range
+!SELECT 9223372036854775808; # Out of int64_t range
+!SELECT * FROM t WHERE a = DATE 'anystring';
+!SELECT * FROM t WHERE a = DATE '1996-12-310';
+!SELECT * FROM t WHERE a = DATE '1996-120-31';
+!SELECT * FROM t WHERE a = DATE '19960-12-31';
+!SELECT * FROM t WHERE a = DATE 'asdf-gh-jkl';

test/queries/queries-bad.sql

@@ -17,6 +17,7 @@ SELECT * FROM t WHERE a BETWEEN 1 and c;
 SELECT * FROM t WHERE a = ? AND b = ?;
 SELECT City.name, Product.category, SUM(price) FROM fact INNER JOIN City ON fact.city_id = City.id INNER JOIN Product ON fact.product_id = Product.id GROUP BY City.name, Product.category;
 SELECT SUBSTR(a, 3, 5) FROM t;
+SELECT * FROM t WHERE a = DATE '1996-12-31';
 # JOIN
 SELECT t1.a, t1.b, t2.c FROM "table" AS t1 JOIN (SELECT * FROM foo JOIN bar ON foo.id = bar.id) t2 ON t1.a = t2.b WHERE (t1.b OR NOT t1.a) AND t2.c = 12.5
 SELECT * FROM t1 JOIN t2 ON c1 = c2;

test/queries/queries-good.sql

@@ -836,3 +836,16 @@ TEST(CastAsDate) {
   ASSERT_STREQ("CAST", stmt->selectList->front()->name);
   ASSERT_EQ(DataType::DATE, stmt->selectList->front()->columnType.data_type);
 }
+
+TEST(DateLiteral) {
+  TEST_PARSE_SINGLE_SQL(
+       "SELECT * FROM t WHERE a = DATE '1996-12-31'",
+        kStmtSelect,
+        SelectStatement,
+        result,
+        stmt);
+  ASSERT_TRUE(result.isValid());
+  stmt = (SelectStatement*) result.getStatement(0);
+  ASSERT_EQ(stmt->whereClause->opType, kOpEquals);
+  ASSERT_STREQ(stmt->whereClause->expr2->name, "1996-12-31");
+}