Fixed safe creation of M2M table for MySQL.

CHANGELOG.rst

@@ -30,6 +30,7 @@ Bugfixes:
 - Fixed comment generation for ``PostgreSQL`` to not duplicate comments
 - Fixed generation of schema for fields that defined custom ``source_field`` values defined
 - Fixed working with Models that have fields with custom ``source_field`` values defined
+- Fixed safe creation of M2M tables for MySQL dialect (#168)
 
 Docs/examples:
 ^^^^^^^^^^^^^^

tortoise/backends/base/schema_generator.py

@@ -1,10 +1,13 @@
+import logging
 import warnings
 from typing import List, Set  # noqa
 
 from tortoise import fields
 from tortoise.exceptions import ConfigurationError
 from tortoise.utils import get_escape_translation_table
 
+logger = logging.getLogger("tortoise")
+
 
 class BaseSchemaGenerator:
     TABLE_CREATE_TEMPLATE = 'CREATE TABLE {exists}"{table_name}" ({fields}){comment};'
@@ -222,15 +225,13 @@ def _get_table_sql(self, model, safe=True) -> dict:
         ]
         if safe and not self.client.capabilities.safe_indexes:
             warnings.warn(
-                "Skipping creation of field indexes for fields {field_names} "
-                'on table "{table_name}" : safe index creation is not supported yet for {dialect}. '
-                "Please find the SQL queries to create the indexes below.".format(
-                    field_names=", ".join(fields_with_index),
-                    table_name=model._meta.table,
-                    dialect=self.client.capabilities.dialect,
+                "Skipping creation of field indexes: safe index creation is not supported yet for "
+                "{dialect}. Please find the SQL queries to create the indexes in the logs.".format(
+                    dialect=self.client.capabilities.dialect
                 )
             )
-            warnings.warn("\n".join(field_indexes_sqls))
+            for fis in field_indexes_sqls:
+                logger.warning(fis)
         else:
             table_create_string = "\n".join([table_create_string, *field_indexes_sqls])
 

tortoise/backends/mysql/schema_generator.py

@@ -8,7 +8,7 @@ class MySQLSchemaGenerator(BaseSchemaGenerator):
     FIELD_TEMPLATE = "`{name}` {type} {nullable} {unique}{comment}"
     FK_TEMPLATE = " REFERENCES `{table}` (`{field}`) ON DELETE {on_delete}{comment}"
     M2M_TABLE_TEMPLATE = (
-        "CREATE TABLE `{table_name}` (\n"
+        "CREATE TABLE {exists}`{table_name}` (\n"
         "    `{backward_key}` {backward_type} NOT NULL REFERENCES `{backward_table}`"
         " (`{backward_field}`) ON DELETE CASCADE,\n"
         "    `{forward_key}` {forward_type} NOT NULL REFERENCES `{forward_table}`"

tortoise/tests/test_generate_schema.py

@@ -1,6 +1,7 @@
 # pylint: disable=C0301
 import re
 import sys
+import warnings
 
 from asynctest.mock import CoroutineMock, patch
 
@@ -185,6 +186,53 @@ async def test_schema(self):
     "event_id" INT NOT NULL REFERENCES "event" (id) ON DELETE CASCADE,
     "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
 ) /* How participants relate */;
+""".strip(),  # noqa
+        )
+
+    @test.skipIf(sys.version_info < (3, 6), "Dict not sorted in 3.5")
+    async def test_schema_safe(self):
+        self.maxDiff = None
+        await self.init_for("tortoise.tests.models_schema_create")
+        sql = get_schema_sql(Tortoise.get_connection("default"), safe=True)
+        self.assertEqual(
+            sql.strip(),
+            """
+CREATE TABLE IF NOT EXISTS "sometable" (
+    "sometable_id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+    "some_chars_table" VARCHAR(255) NOT NULL,
+    "fk_sometable" INT REFERENCES "sometable" (sometable_id) ON DELETE CASCADE
+);
+CREATE INDEX IF NOT EXISTS "sometable_some_ch_115115_idx" ON "sometable" (some_chars_table);
+CREATE TABLE IF NOT EXISTS "team" (
+    "name" VARCHAR(50) NOT NULL  PRIMARY KEY /* The TEAM name (and PK) */,
+    "manager_id" VARCHAR(50)   /* The TEAM name (and PK) */ REFERENCES "team" (name) ON DELETE CASCADE
+) /* The TEAMS! */;
+CREATE TABLE IF NOT EXISTS "tournament" (
+    "tid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+    "name" TEXT NOT NULL  /* Tournament name */,
+    "created" TIMESTAMP NOT NULL  /* Created *\\/'`\\/* datetime */
+) /* What Tournaments *\\/'`\\/* we have */;
+CREATE INDEX IF NOT EXISTS "tournament_name_116110_idx" ON "tournament" (name);
+CREATE TABLE IF NOT EXISTS "event" (
+    "id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL /* Event ID */,
+    "name" TEXT NOT NULL UNIQUE,
+    "modified" TIMESTAMP NOT NULL,
+    "prize" VARCHAR(40),
+    "token" VARCHAR(100) NOT NULL UNIQUE /* Unique token */,
+    "tournament_id" INT NOT NULL REFERENCES "tournament" (tid) ON DELETE CASCADE /* FK to tournament */
+) /* This table contains a list of all the events */;
+CREATE TABLE IF NOT EXISTS "sometable_self" (
+    "backward_sts" INT NOT NULL REFERENCES "sometable" (sometable_id) ON DELETE CASCADE,
+    "sts_forward" INT NOT NULL REFERENCES "sometable" (sometable_id) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "team_team" (
+    "team_rel_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE,
+    "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "teamevents" (
+    "event_id" INT NOT NULL REFERENCES "event" (id) ON DELETE CASCADE,
+    "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
+) /* How participants relate */;
 """.strip(),  # noqa
         )
 
@@ -288,6 +336,72 @@ async def test_schema(self):
     `event_id` INT NOT NULL REFERENCES `event` (`id`) ON DELETE CASCADE,
     `team_id` VARCHAR(50) NOT NULL REFERENCES `team` (`name`) ON DELETE CASCADE
 ) COMMENT='How participants relate';
+""".strip(),  # noqa
+        )
+
+    @test.skipIf(sys.version_info < (3, 6), "Dict not sorted in 3.5")
+    async def test_schema_safe(self):
+        self.maxDiff = None
+        await self.init_for("tortoise.tests.models_schema_create")
+        with warnings.catch_warnings(record=True) as w:
+            with self.assertLogs("tortoise", level="WARNING") as cm:
+                sql = get_schema_sql(Tortoise.get_connection("default"), safe=True)
+
+        self.assertEqual(
+            cm.output,
+            [
+                "WARNING:tortoise:CREATE INDEX `sometable_some_ch_115115_idx` ON `sometable`"
+                " (some_chars_table);",
+                "WARNING:tortoise:CREATE INDEX `tournament_name_116110_idx` ON `tournament`"
+                " (name);",
+            ],
+        )
+
+        self.assertEqual(len(w), 1)
+        self.assertEqual(w[0].category, UserWarning)
+        self.assertEqual(
+            str(w[0].message),
+            "Skipping creation of field indexes: safe index creation is not supported yet for"
+            " mysql. Please find the SQL queries to create the indexes in the logs.",
+        )
+
+        self.assertEqual(
+            sql.strip(),
+            """
+CREATE TABLE IF NOT EXISTS `sometable` (
+    `sometable_id` INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
+    `some_chars_table` VARCHAR(255) NOT NULL,
+    `fk_sometable` INT REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS `team` (
+    `name` VARCHAR(50) NOT NULL  COMMENT 'The TEAM name (and PK)',
+    `manager_id` VARCHAR(50)   COMMENT 'The TEAM name (and PK)' REFERENCES `team` (`name`) ON DELETE CASCADE
+) COMMENT='The TEAMS!';
+CREATE TABLE IF NOT EXISTS `tournament` (
+    `tid` INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
+    `name` TEXT NOT NULL  COMMENT 'Tournament name',
+    `created` DATETIME(6) NOT NULL  COMMENT 'Created */\\'`/* datetime'
+) COMMENT='What Tournaments */\\'`/* we have';
+CREATE TABLE IF NOT EXISTS `event` (
+    `id` INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT COMMENT 'Event ID',
+    `name` TEXT NOT NULL UNIQUE,
+    `modified` DATETIME(6) NOT NULL,
+    `prize` DECIMAL(10,2),
+    `token` VARCHAR(100) NOT NULL UNIQUE COMMENT 'Unique token',
+    `tournament_id` INT NOT NULL REFERENCES `tournament` (`tid`) ON DELETE CASCADE COMMENT 'FK to tournament'
+) COMMENT='This table contains a list of all the events';
+CREATE TABLE IF NOT EXISTS `sometable_self` (
+    `backward_sts` INT NOT NULL REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE,
+    `sts_forward` INT NOT NULL REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS `team_team` (
+    `team_rel_id` VARCHAR(50) NOT NULL REFERENCES `team` (`name`) ON DELETE CASCADE,
+    `team_id` VARCHAR(50) NOT NULL REFERENCES `team` (`name`) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS `teamevents` (
+    `event_id` INT NOT NULL REFERENCES `event` (`id`) ON DELETE CASCADE,
+    `team_id` VARCHAR(50) NOT NULL REFERENCES `team` (`name`) ON DELETE CASCADE
+) COMMENT='How participants relate';
 """.strip(),  # noqa
         )
 
@@ -389,5 +503,63 @@ async def test_schema(self):
     "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
 );
 COMMENT ON TABLE teamevents IS 'How participants relate';
+""".strip(),
+        )
+
+    @test.skipIf(sys.version_info < (3, 6), "Dict not sorted in 3.5")
+    async def test_schema_safe(self):
+        self.maxDiff = None
+        await self.init_for("tortoise.tests.models_schema_create")
+        sql = get_schema_sql(Tortoise.get_connection("default"), safe=True)
+        self.assertEqual(
+            sql.strip(),
+            """
+CREATE TABLE IF NOT EXISTS "sometable" (
+    "sometable_id" SERIAL NOT NULL PRIMARY KEY,
+    "some_chars_table" VARCHAR(255) NOT NULL,
+    "fk_sometable" INT REFERENCES "sometable" (sometable_id) ON DELETE CASCADE
+);
+CREATE INDEX IF NOT EXISTS "sometable_some_ch_115115_idx" ON "sometable" (some_chars_table);
+CREATE TABLE IF NOT EXISTS "team" (
+    "name" VARCHAR(50) NOT NULL  PRIMARY KEY,
+    "manager_id" VARCHAR(50) REFERENCES "team" (name) ON DELETE CASCADE
+);
+COMMENT ON COLUMN team.name IS 'The TEAM name (and PK)';
+COMMENT ON COLUMN team.manager_id IS 'The TEAM name (and PK)';
+COMMENT ON TABLE team IS 'The TEAMS!';
+CREATE TABLE IF NOT EXISTS "tournament" (
+    "tid" SERIAL NOT NULL PRIMARY KEY,
+    "name" TEXT NOT NULL,
+    "created" TIMESTAMP NOT NULL
+);
+CREATE INDEX IF NOT EXISTS "tournament_name_116110_idx" ON "tournament" (name);
+COMMENT ON COLUMN tournament.name IS 'Tournament name';
+COMMENT ON COLUMN tournament.created IS 'Created */''`/* datetime';
+COMMENT ON TABLE tournament IS 'What Tournaments */''`/* we have';
+CREATE TABLE IF NOT EXISTS "event" (
+    "id" SERIAL NOT NULL PRIMARY KEY,
+    "name" TEXT NOT NULL UNIQUE,
+    "modified" TIMESTAMP NOT NULL,
+    "prize" DECIMAL(10,2),
+    "token" VARCHAR(100) NOT NULL UNIQUE,
+    "tournament_id" INT NOT NULL REFERENCES "tournament" (tid) ON DELETE CASCADE
+);
+COMMENT ON COLUMN event.id IS 'Event ID';
+COMMENT ON COLUMN event.token IS 'Unique token';
+COMMENT ON COLUMN event.tournament_id IS 'FK to tournament';
+COMMENT ON TABLE event IS 'This table contains a list of all the events';
+CREATE TABLE IF NOT EXISTS "sometable_self" (
+    "backward_sts" INT NOT NULL REFERENCES "sometable" (sometable_id) ON DELETE CASCADE,
+    "sts_forward" INT NOT NULL REFERENCES "sometable" (sometable_id) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "team_team" (
+    "team_rel_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE,
+    "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "teamevents" (
+    "event_id" INT NOT NULL REFERENCES "event" (id) ON DELETE CASCADE,
+    "team_id" VARCHAR(50) NOT NULL REFERENCES "team" (name) ON DELETE CASCADE
+);
+COMMENT ON TABLE teamevents IS 'How participants relate';
 """.strip(),
         )