fix: Implement modulus operator

Author: aholyoke

sqlalchemy_bigquery/base.py

@@ -579,6 +579,9 @@ def visit_regexp_match_op_binary(self, binary, operator, **kw):
     def visit_not_regexp_match_op_binary(self, binary, operator, **kw):
         return "NOT %s" % self.visit_regexp_match_op_binary(binary, operator, **kw)
 
+    def visit_mod_binary(self, binary, operator, **kw):
+        return f"MOD({self.process(binary.left, **kw)}, {self.process(binary.right, **kw)})"
+
 
 class BigQueryTypeCompiler(GenericTypeCompiler):
     def visit_INTEGER(self, type_, **kw):

tests/unit/test_select.py

@@ -486,3 +486,16 @@ def test_visit_not_regexp_match_op_binary(faux_conn):
     expected = "NOT REGEXP_CONTAINS(`table`.`foo`, %(foo_1:STRING)s)"
 
     assert result == expected
+
+
+def test_visit_mod_binary(faux_conn):
+    table = setup_table(
+        faux_conn,
+        "table",
+        sqlalchemy.Column("foo", sqlalchemy.Integer),
+    )
+    sql_statement = table.c.foo % 2
+    result = sql_statement.compile(faux_conn).string
+    expected = "MOD(`table`.`foo`, %(foo_1:INT64)s)"
+
+    assert result == expected