Merge "Support DEFAULT VALUES and VALUES(DEFAULT) individually"

4 files changed, 17 insertions, 0 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index f45d5ec91..c5113b054 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -2534,6 +2534,11 @@ class MySQLDialect(default.DefaultDialect):
     supports_for_update_of = False  # default for MySQL ...
     # ... may be updated to True for MySQL 8+ in initialize()
 
+    # MySQL doesn't support "DEFAULT VALUES" but *does* support
+    # "VALUES (DEFAULT)"
+    supports_default_values = False
+    supports_default_metavalue = True
+
     supports_sane_rowcount = True
     supports_sane_multi_rowcount = False
     supports_multivalues_insert = True
diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index 6496c4f71..3e1f50fc8 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -1453,7 +1453,11 @@ class OracleDialect(default.DefaultDialect):
     requires_name_normalize = True
 
     supports_comments = True
+
+    # Oracle supports these syntaxes but I'm not able to get them
+    # to work with RETURNING which we usually need
     supports_default_values = False
+    supports_default_metavalue = True
     supports_empty_insert = False
 
     statement_compiler = OracleCompiler
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 3b419ed16..0e9968031 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -3079,6 +3079,9 @@ class PGDialect(default.DefaultDialect):
 
     supports_comments = True
     supports_default_values = True
+
+    supports_default_metavalue = True
+
     supports_empty_insert = False
     supports_multivalues_insert = True
     default_paramstyle = "pyformat"
diff --git a/lib/sqlalchemy/dialects/sqlite/base.py b/lib/sqlalchemy/dialects/sqlite/base.py
index 28901d028..0075b3876 100644
--- a/lib/sqlalchemy/dialects/sqlite/base.py
+++ b/lib/sqlalchemy/dialects/sqlite/base.py
@@ -1791,7 +1791,12 @@ class SQLiteDialect(default.DefaultDialect):
     supports_alter = False
     supports_unicode_statements = True
     supports_unicode_binds = True
+
+    # SQlite supports "DEFAULT VALUES" but *does not* support
+    # "VALUES (DEFAULT)"
     supports_default_values = True
+    supports_default_metavalue = False
+
     supports_empty_insert = False
     supports_cast = True
     supports_multivalues_insert = True