PGDialect.get_check_constraints: Handle "NOT VALID"

Added support for reflection of CHECK constraints that include the special
PostgreSQL qualifier "NOT VALID", which can be present for CHECK
constraints that were added to an exsiting table with the directive that
they not be applied to existing data in the table. The PostgreSQL
dictionary for CHECK constraints as returned by
:meth:`.Inspector.get_check_constraints` may include an additional entry
``dialect_options`` which within will contain an entry ``"not_valid":
True`` if this symbol is detected.   Pull request courtesy Bill Finn.

Fixes: #4824
Closes: #4825
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4825
Pull-request-sha: a0e1ab133c2d46521a74e55423ac2ba866682dae

Change-Id: I78365f50055c95474c92124b85df66c5c80c00c8

diff --git a/doc/build/changelog/unreleased_13/4824.rst b/doc/build/changelog/unreleased_13/4824.rst
new file mode 100644 (file)
index 0000000..0a624b3
--- /dev/null
+++ b/doc/build/changelog/unreleased_13/4824.rst
@@ -0,0 +1,12 @@
+.. change::
+    :tags: usecase, postgresql
+    :tickets: 4824
+
+    Added support for reflection of CHECK constraints that include the special
+    PostgreSQL qualifier "NOT VALID", which can be present for CHECK
+    constraints that were added to an exsiting table with the directive that
+    they not be applied to existing data in the table. The PostgreSQL
+    dictionary for CHECK constraints as returned by
+    :meth:`.Inspector.get_check_constraints` may include an additional entry
+    ``dialect_options`` which within will contain an entry ``"not_valid":
+    True`` if this symbol is detected.   Pull request courtesy Bill Finn.

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 8fbd97ebe1f4496f0519b18aa6be267140824c0d..0ea6d429607c9df2a49f945d1bca81a7c5660539 100644 (file)
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -3447,20 +3447,24 @@ class PGDialect(default.DefaultDialect):
 
         c = connection.execute(sql.text(CHECK_SQL), table_oid=table_oid)
 
-        # samples:
-        # "CHECK (((a > 1) AND (a < 5)))"
-        # "CHECK (((a = 1) OR ((a > 2) AND (a < 5))))"
-        def match_cons(src):
-            m = re.match(r"^CHECK *\(\((.+)\)\)$", src)
+        ret = []
+        for name, src in c:
+            # samples:
+            # "CHECK (((a > 1) AND (a < 5)))"
+            # "CHECK (((a = 1) OR ((a > 2) AND (a < 5))))"
+            # "CHECK (((a > 1) AND (a < 5))) NOT VALID"
+            m = re.match(r"^CHECK *\(\((.+)\)\)( NOT VALID)?$", src)
             if not m:
                 util.warn("Could not parse CHECK constraint text: %r" % src)
-                return ""
-            return m.group(1)
+                sqltext = ""
+            else:
+                sqltext = m.group(1)
+            entry = {"name": name, "sqltext": sqltext}
+            if m and m.group(2):
+                entry["dialect_options"] = {"not_valid": True}
 
-        return [
-            {"name": name, "sqltext": match_cons(src)}
-            for name, src in c.fetchall()
-        ]
+            ret.append(entry)
+        return ret
 
     def _load_enums(self, connection, schema=None):
         schema = schema or self.default_schema_name

diff --git a/lib/sqlalchemy/engine/reflection.py b/lib/sqlalchemy/engine/reflection.py
index 872a21bb767ea76eb2390e3c2f33b01d119af17d..e36d99d5d19f848d2ec28f05c6390afeb95e3801 100644 (file)
--- a/lib/sqlalchemy/engine/reflection.py
+++ b/lib/sqlalchemy/engine/reflection.py
@@ -541,6 +541,12 @@ class Inspector(object):
         sqltext
           the check constraint's SQL expression
 
+        dialect_options
+          may or may not be present; a dictionary with additional
+          dialect-specific options for this CHECK constraint
+
+          .. versionadded:: 1.3.8
+
         :param table_name: string name of the table.  For special quoting,
          use :class:`.quoted_name`.
 

diff --git a/test/dialect/postgresql/test_reflection.py b/test/dialect/postgresql/test_reflection.py
index 4b5c4b949d278f441b17c5fdc796e143953b1031..7054a9fddf56b048fd4fbb932846bf0cda4a5112 100644 (file)
--- a/test/dialect/postgresql/test_reflection.py
+++ b/test/dialect/postgresql/test_reflection.py
@@ -1540,9 +1540,10 @@ class ReflectionTest(fixtures.TestBase):
         )
 
     def test_reflect_check_warning(self):
+        rows = [("some name", "NOTCHECK foobar")]
         conn = mock.Mock(
-            execute=lambda *arg, **kw: mock.Mock(
-                fetchall=lambda: [("some name", "NOTCHECK foobar")]
+            execute=lambda *arg, **kw: mock.MagicMock(
+                fetchall=lambda: rows, __iter__=lambda self: iter(rows)
             )
         )
         with mock.patch.object(
@@ -1553,6 +1554,30 @@ class ReflectionTest(fixtures.TestBase):
             ):
                 testing.db.dialect.get_check_constraints(conn, "foo")
 
+    def test_reflect_with_not_valid_check_constraint(self):
+        rows = [("some name", "CHECK ((a IS NOT NULL)) NOT VALID")]
+        conn = mock.Mock(
+            execute=lambda *arg, **kw: mock.MagicMock(
+                fetchall=lambda: rows, __iter__=lambda self: iter(rows)
+            )
+        )
+        with mock.patch.object(
+            testing.db.dialect, "get_table_oid", lambda *arg, **kw: 1
+        ):
+            check_constraints = testing.db.dialect.get_check_constraints(
+                conn, "foo"
+            )
+            eq_(
+                check_constraints,
+                [
+                    {
+                        "name": "some name",
+                        "sqltext": "a IS NOT NULL",
+                        "dialect_options": {"not_valid": True},
+                    }
+                ],
+            )
+
 
 class CustomTypeReflectionTest(fixtures.TestBase):
     class CustomType(object):