- The change in :ticket:`2721`, which is that the ``deferrable`` keyword

of :class:`.ForeignKeyConstraint` is silently ignored on the MySQL
backend, will be reverted as of 0.9; this keyword will now render again, raising
errors on MySQL as it is not understood - the same behavior will also
apply to the ``initially`` keyword.  In 0.8, the keywords will remain
ignored but a warning is emitted.   Additionally, the ``match`` keyword
now raises a :class:`.CompileError` on 0.9 and emits a warning on 0.8;
this keyword is not only silently ignored by MySQL but also breaks
the ON UPDATE/ON DELETE options.

To use a :class:`.ForeignKeyConstraint`
that does not render or renders differently on MySQL, use a custom
compilation option.  An example of this usage has been added to the
documentation, see :ref:`mysql_foreign_keys`.
[ticket:2721] [ticket:2839]

1 files changed, 17 insertions, 3 deletions

diff --git a/test/dialect/mysql/test_compiler.py b/test/dialect/mysql/test_compiler.py
index d1488ed33..a50c6a901 100644
--- a/test/dialect/mysql/test_compiler.py
+++ b/test/dialect/mysql/test_compiler.py
@@ -104,17 +104,31 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
             "CREATE INDEX bar ON foo (x > 5)"
         )
 
-    def test_skip_deferrable_kw(self):
+    def test_deferrable_initially_kw_not_ignored(self):
         m = MetaData()
         t1 = Table('t1', m, Column('id', Integer, primary_key=True))
         t2 = Table('t2', m, Column('id', Integer,
-                        ForeignKey('t1.id', deferrable=True),
+                        ForeignKey('t1.id', deferrable=True, initially="XYZ"),
                             primary_key=True))
 
         self.assert_compile(
             schema.CreateTable(t2),
             "CREATE TABLE t2 (id INTEGER NOT NULL, "
-            "PRIMARY KEY (id), FOREIGN KEY(id) REFERENCES t1 (id))"
+            "PRIMARY KEY (id), FOREIGN KEY(id) REFERENCES t1 (id) DEFERRABLE INITIALLY XYZ)"
+        )
+
+    def test_match_kw_raises(self):
+        m = MetaData()
+        t1 = Table('t1', m, Column('id', Integer, primary_key=True))
+        t2 = Table('t2', m, Column('id', Integer,
+                        ForeignKey('t1.id', match="XYZ"),
+                            primary_key=True))
+
+        assert_raises_message(
+            exc.CompileError,
+            "MySQL ignores the 'MATCH' keyword while at the same time causes "
+            "ON UPDATE/ON DELETE clauses to be ignored.",
+            schema.CreateTable(t2).compile, dialect=mysql.dialect()
         )
 
 class SQLTest(fixtures.TestBase, AssertsCompiledSQL):