De-emphasize notion of "default driver" (DBAPI)

Fixes: #6960

Even though a default driver still exists for
each dialect, remove most usages of `dialect://`
to encourage users to explicitly specify
`dialect+driver://`

Change-Id: I0ad42167582df509138fca64996bbb53e379b1af

5 files changed, 9 insertions, 9 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index 63a11fcc7..5382e00db 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -213,7 +213,7 @@ techniques are used.
 To set isolation level using :func:`_sa.create_engine`::
 
     engine = create_engine(
-                    "mysql://scott:tiger@localhost/test",
+                    "mysql+mysqldb://scott:tiger@localhost/test",
                     isolation_level="READ UNCOMMITTED"
                 )
 
@@ -423,7 +423,7 @@ the ``first_connect`` and ``connect`` events::
 
     from sqlalchemy import create_engine, event
 
-    eng = create_engine("mysql://scott:tiger@localhost/test", echo='debug')
+    eng = create_engine("mysql+mysqldb://scott:tiger@localhost/test", echo='debug')
 
     # `insert=True` will ensure this is the very first listener to run
     @event.listens_for(eng, "connect", insert=True)
@@ -950,7 +950,7 @@ SQLAlchemy also emits NOT NULL for TIMESTAMP columns that do specify
 
 
     from sqlalchemy import create_engine
-    e = create_engine("mysql://scott:tiger@localhost/test", echo=True)
+    e = create_engine("mysql+mysqldb://scott:tiger@localhost/test", echo=True)
     m.create_all(e)
 
 output::
diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index 9e62b931d..5a43205df 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -306,7 +306,7 @@ an INSERT in order to increment a sequence within an INSERT statement and get
 the value back at the same time. To disable this feature across the board,
 specify ``implicit_returning=False`` to :func:`_sa.create_engine`::
 
-    engine = create_engine("oracle://scott:tiger@dsn",
+    engine = create_engine("oracle+cx_oracle://scott:tiger@dsn",
                            implicit_returning=False)
 
 Implicit returning can also be disabled on a table-by-table basis as a table
@@ -450,7 +450,7 @@ the ``exclude_tablespaces`` parameter::
 
     # exclude SYSAUX and SOME_TABLESPACE, but not SYSTEM
     e = create_engine(
-      "oracle://scott:tiger@xe",
+      "oracle+cx_oracle://scott:tiger@xe",
       exclude_tablespaces=["SYSAUX", "SOME_TABLESPACE"])
 
 .. versionadded:: 1.1
diff --git a/lib/sqlalchemy/dialects/oracle/cx_oracle.py b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
index 38e864898..590c9d47c 100644
--- a/lib/sqlalchemy/dialects/oracle/cx_oracle.py
+++ b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
@@ -158,7 +158,7 @@ SQLAlchemy's pooling::
 	encoding="UTF-8", nencoding="UTF-8"
     )
 
-    engine = create_engine("oracle://", creator=pool.acquire, poolclass=NullPool)
+    engine = create_engine("oracle+cx_oracle://", creator=pool.acquire, poolclass=NullPool)
 
 The above engine may then be used normally where cx_Oracle's pool handles
 connection pooling::
@@ -196,7 +196,7 @@ This can be achieved by wrapping ``pool.acquire()``::
     def creator():
         return pool.acquire(cclass="MYCLASS", purity=cx_Oracle.ATTR_PURITY_SELF)
 
-    engine = create_engine("oracle://", creator=creator, poolclass=NullPool)
+    engine = create_engine("oracle+cx_oracle://", creator=creator, poolclass=NullPool)
 
 The above engine may then be used normally where cx_Oracle handles session
 pooling and Oracle Database additionally uses DRCP::
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 87afa0293..a00c26e87 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -346,7 +346,7 @@ were set to include ``test_schema``, and we invoked a table
 reflection process as follows::
 
     >>> from sqlalchemy import Table, MetaData, create_engine, text
-    >>> engine = create_engine("postgresql://scott:tiger@localhost/test")
+    >>> engine = create_engine("postgresql+psycopg2://scott:tiger@localhost/test")
     >>> with engine.connect() as conn:
     ...     conn.execute(text("SET search_path TO test_schema, public"))
     ...     meta = MetaData()
diff --git a/lib/sqlalchemy/dialects/postgresql/json.py b/lib/sqlalchemy/dialects/postgresql/json.py
index 2acf177f5..ef046e3ae 100644
--- a/lib/sqlalchemy/dialects/postgresql/json.py
+++ b/lib/sqlalchemy/dialects/postgresql/json.py
@@ -159,7 +159,7 @@ class JSON(sqltypes.JSON):
     using psycopg2, the DBAPI only allows serializers at the per-cursor
     or per-connection level.   E.g.::
 
-        engine = create_engine("postgresql://scott:tiger@localhost/test",
+        engine = create_engine("postgresql+psycopg2://scott:tiger@localhost/test",
                                 json_serializer=my_serialize_fn,
                                 json_deserializer=my_deserialize_fn
                         )