compiler: add support for multirow inserts

Some databases support this syntax for inserts:

INSERT INTO table (id, name) VALUES
('v1', 'v2'),
('v3', 'v4');

which greatly increases INSERT speed.

It is now possible to pass a list of lists/tuples/dictionaries as
the values param to the Insert construct. We convert it to a flat
dictionary so we can continue using bind params. The above query
will be converted to:

INSERT INTO table (id, name) VALUES
(:id, :name),
(:id0, :name0);

Currently only supported on postgresql, mysql and sqlite.

3 files changed, 3 insertions, 0 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index 2cda1a147..5f515c936 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1882,6 +1882,7 @@ class MySQLDialect(default.DefaultDialect):
 
     supports_sane_rowcount = True
     supports_sane_multi_rowcount = False
+    supports_multirow_insert = True
 
     default_paramstyle = 'format'
     colspecs = colspecs
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index ed24bc1fe..22667b317 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -1182,6 +1182,7 @@ class PGDialect(default.DefaultDialect):
 
     supports_default_values = True
     supports_empty_insert = False
+    supports_multirow_insert = True
     default_paramstyle = 'pyformat'
     ischema_names = ischema_names
     colspecs = colspecs
diff --git a/lib/sqlalchemy/dialects/sqlite/base.py b/lib/sqlalchemy/dialects/sqlite/base.py
index 6d2d0e89d..d1532b9bb 100644
--- a/lib/sqlalchemy/dialects/sqlite/base.py
+++ b/lib/sqlalchemy/dialects/sqlite/base.py
@@ -601,6 +601,7 @@ class SQLiteDialect(default.DefaultDialect):
     supports_default_values = True
     supports_empty_insert = False
     supports_cast = True
+    supports_multirow_insert = True
 
     default_paramstyle = 'qmark'
     execution_ctx_cls = SQLiteExecutionContext