Set hasMultipleTables: true when appropriate

moor/test/data/tables/custom_tables.g.dart

@@ -1157,6 +1157,24 @@ abstract class _$CustomTablesDb extends GeneratedDatabase {
         readsFrom: {config}).map(_rowToConfig);
   }
 
+  MultipleResult _rowToMultipleResult(QueryRow row) {
+    return MultipleResult(
+      a: row.readString('a'),
+      b: row.readInt('b'),
+      c: row.readDouble('c'),
+      a1: row.readString('a'),
+      b1: row.readInt('b'),
+    );
+  }
+
+  Selectable<MultipleResult> multiple(Expression<bool, BoolType> predicate) {
+    final generatedpredicate = $write(predicate, hasMultipleTables: true);
+    return customSelectQuery(
+        'SELECT * FROM with_constraints c\n INNER JOIN with_defaults d\n   ON d.a = c.a AND d.b = c.b\n WHERE ${generatedpredicate.sql}',
+        variables: [...generatedpredicate.introducedVariables],
+        readsFrom: {withConstraints, withDefaults}).map(_rowToMultipleResult);
+  }
+
   EMail _rowToEMail(QueryRow row) {
     return EMail(
       sender: row.readString('sender'),
@@ -1208,6 +1226,33 @@ abstract class _$CustomTablesDb extends GeneratedDatabase {
       [noIds, withDefaults, withConstraints, config, mytable, email];
 }
 
+class MultipleResult {
+  final String a;
+  final int b;
+  final double c;
+  final String a1;
+  final int b1;
+  MultipleResult({
+    this.a,
+    this.b,
+    this.c,
+    this.a1,
+    this.b1,
+  });
+  @override
+  int get hashCode => $mrjf($mrjc(a.hashCode,
+      $mrjc(b.hashCode, $mrjc(c.hashCode, $mrjc(a1.hashCode, b1.hashCode)))));
+  @override
+  bool operator ==(dynamic other) =>
+      identical(this, other) ||
+      (other is MultipleResult &&
+          other.a == this.a &&
+          other.b == this.b &&
+          other.c == this.c &&
+          other.a1 == this.a1 &&
+          other.b1 == this.b1);
+}
+
 class ReadRowIdResult {
   final int rowid;
   final String configKey;

moor/test/data/tables/tables.moor

@@ -34,6 +34,11 @@ readMultiple: SELECT * FROM config WHERE config_key IN ? ORDER BY $clause;
 readDynamic: SELECT * FROM config WHERE $predicate;
 findValidJsons: SELECT * FROM config WHERE json_valid(config_value);
 
+multiple: SELECT * FROM with_constraints c
+ INNER JOIN with_defaults d
+   ON d.a = c.a AND d.b = c.b
+ WHERE $predicate;
+
 searchEmails: SELECT * FROM email WHERE email MATCH :term ORDER BY rank;
 
 readRowId: SELECT oid, * FROM config WHERE _rowid_ = $expr;

moor_generator/lib/src/writer/queries/query_writer.dart

@@ -296,8 +296,13 @@ class QueryWriter {
           ..write(_placeholderContextName(element))
           ..write(' = ')
           ..write(r'$write(')
-          ..write(element.dartParameterName)
-          ..write(');\n');
+          ..write(element.dartParameterName);
+
+        if (query.hasMultipleTables) {
+          _buffer.write(', hasMultipleTables: true');
+        }
+
+        _buffer.write(');\n');
 
         // similar to the case for expanded array variables, we need to
         // increase the index