Add support for comma-separated tables in CROSS JOIN ... USING/ON syntax to close #130 (#2301)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: mathiasrw <[email protected]>
Co-authored-by: M. Wulff <[email protected]>

Author: Copilot

src/421join.js

@@ -15,13 +15,14 @@ yy.Select.prototype.compileJoins = function (query) {
 
 	this.joins.forEach(jn => {
 		let tq, ps, source;
-		// Test CROSS-JOIN
+		// Handle CROSS JOIN (SQLite-compatible behavior)
+		// SQLite allows CROSS JOIN with ON/USING clauses, treating them as INNER JOIN
 		if (jn.joinmode === 'CROSS') {
-			if (jn.using || jn.on) {
-				throw new Error('CROSS JOIN cannot have USING or ON clauses');
-			} else {
-				jn.joinmode = 'INNER';
-			}
+			// Convert all CROSS JOINs to INNER JOIN for consistent processing
+			// Result behavior:
+			// - Without ON/USING: Produces cartesian product (standard CROSS JOIN)
+			// - With ON/USING: Filters results like INNER JOIN (SQLite extension)
+			jn.joinmode = 'INNER';
 		}
 
 		if (jn instanceof yy.Apply) {

src/alasqlparser.jison

@@ -853,6 +853,32 @@ FromClause
 		{ $$ = { from: [$2], joins: $3 }; }
 */	| FROM FromTablesList JoinTablesList
 		{ $$ = { from: $2, joins: $3 }; }
+	| FROM FromTablesList JoinTablesList COMMA FromTablesList
+		{ 
+			// Convert comma-separated tables after joins into CROSS JOINs
+			var joins = $3;
+			$5.forEach(t => {
+				var join = new yy.Join({joinmode:"CROSS"});
+				if(t.tableid) {
+					join.table = new yy.Table({databaseid:t.databaseid, tableid:t.tableid});
+				} else if(t instanceof yy.Select) {
+					join.select = t;
+				} else if(t instanceof yy.Search) {
+					join.search = t;
+				} else if(t instanceof yy.ParamValue) {
+					join.param = t;
+				} else if(t instanceof yy.VarValue) {
+					join.variable = t.variable;
+				} else if(t instanceof yy.FuncValue) {
+					join.func = t;
+				} else if(t instanceof yy.Json) {
+					join.json = t;
+				}
+				if(t.as) join.as = t.as;
+				joins.push(join);
+			});
+			$$ = { from: $2, joins: joins }; 
+		}
 /*	| FROM LPAR FromTable JoinTablesList RPAR
 		{ $$ = { from: [$3], joins: $4 }; }
 */	| FROM LPAR FromTablesList JoinTablesList RPAR