Names ForeignKey constraints in a consistent way (#203)

tortoise · Oct 1, 2019 · c87bbc2 · c87bbc2
1 parent e0fea4f
commit c87bbc2
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diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -2,6 +2,9 @@
 
 Changelog
 =========
+0.13.10
+-------
+- Names ForeignKey constraints in a consistent way
 
 0.13.9
 ------

diff --git a/tests/models_schema_create.py b/tests/models_schema_create.py
@@ -7,7 +7,7 @@
 
 class Tournament(Model):
     tid = fields.SmallIntField(pk=True)
-    name = fields.TextField(description="Tournament name", index=True)
+    name = fields.CharField(max_length=100, description="Tournament name", index=True)
     created = fields.DatetimeField(auto_now_add=True, description="Created */'`/* datetime")
 
     class Meta:
@@ -16,7 +16,7 @@ class Meta:
 
 class Event(Model):
     id = fields.BigIntField(pk=True, description="Event ID")
-    name = fields.TextField(unique=True)
+    name = fields.TextField()
     tournament = fields.ForeignKeyField(
         "models.Tournament", related_name="events", description="FK to tournament"
     )

diff --git a/tests/test_generate_schema.py b/tests/test_generate_schema.py
@@ -165,13 +165,13 @@ async def test_schema(self):
 ) /* The TEAMS! */;
 CREATE TABLE "tournament" (
     "tid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
-    "name" TEXT NOT NULL  /* Tournament name */,
+    "name" VARCHAR(100) NOT NULL  /* Tournament name */,
     "created" TIMESTAMP NOT NULL  /* Created *\\/'`\\/* datetime */
 ) /* What Tournaments *\\/'`\\/* we have */;
 CREATE INDEX "tournament_name_116110_idx" ON "tournament" (name);
 CREATE TABLE "event" (
     "id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL /* Event ID */,
-    "name" TEXT NOT NULL UNIQUE,
+    "name" TEXT NOT NULL,
     "modified" TIMESTAMP NOT NULL,
     "prize" VARCHAR(40),
     "token" VARCHAR(100) NOT NULL UNIQUE /* Unique token */,
@@ -216,13 +216,13 @@ async def test_schema_safe(self):
 ) /* The TEAMS! */;
 CREATE TABLE IF NOT EXISTS "tournament" (
     "tid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
-    "name" TEXT NOT NULL  /* Tournament name */,
+    "name" VARCHAR(100) 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,
+    "name" TEXT NOT NULL,
     "modified" TIMESTAMP NOT NULL,
     "prize" VARCHAR(40),
     "token" VARCHAR(100) NOT NULL UNIQUE /* Unique token */,
@@ -323,28 +323,28 @@ async def test_schema(self):
     `sometable_id` INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
     `some_chars_table` VARCHAR(255) NOT NULL,
     `fk_sometable` INT,
-    FOREIGN KEY (`fk_sometable`) REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE,
+    CONSTRAINT `fk_sometabl_sometabl_6efae9bd` FOREIGN KEY (`fk_sometable`) REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE,
     KEY `sometable_some_ch_115115_idx` (`some_chars_table`)
 ) CHARACTER SET utf8mb4;
 CREATE TABLE `team` (
     `name` VARCHAR(50) NOT NULL  PRIMARY KEY COMMENT 'The TEAM name (and PK)',
     `manager_id` VARCHAR(50),
-    FOREIGN KEY (`manager_id`) REFERENCES `team` (`name`) ON DELETE CASCADE
+    CONSTRAINT `fk_team_team_9c77cd8f` FOREIGN KEY (`manager_id`) REFERENCES `team` (`name`) ON DELETE CASCADE
 ) CHARACTER SET utf8mb4 COMMENT='The TEAMS!';
 CREATE TABLE `tournament` (
     `tid` SMALLINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
-    `name` TEXT NOT NULL  COMMENT 'Tournament name',
+    `name` VARCHAR(100) NOT NULL  COMMENT 'Tournament name',
     `created` DATETIME(6) NOT NULL  COMMENT 'Created */\\'`/* datetime',
     KEY `tournament_name_116110_idx` (`name`)
 ) CHARACTER SET utf8mb4 COMMENT='What Tournaments */\\'`/* we have';
 CREATE TABLE `event` (
     `id` BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT COMMENT 'Event ID',
-    `name` TEXT NOT NULL UNIQUE,
+    `name` TEXT NOT NULL,
     `modified` DATETIME(6) NOT NULL,
     `prize` DECIMAL(10,2),
     `token` VARCHAR(100) NOT NULL UNIQUE COMMENT 'Unique token',
     `tournament_id` SMALLINT NOT NULL COMMENT 'FK to tournament',
-    FOREIGN KEY (`tournament_id`) REFERENCES `tournament` (`tid`) ON DELETE CASCADE
+    CONSTRAINT `fk_event_tourname_51c2b82d` FOREIGN KEY (`tournament_id`) REFERENCES `tournament` (`tid`) ON DELETE CASCADE
 ) CHARACTER SET utf8mb4 COMMENT='This table contains a list of all the events';
 CREATE TABLE `sometable_self` (
     `backward_sts` INT NOT NULL,
@@ -384,28 +384,28 @@ async def test_schema_safe(self):
     `sometable_id` INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
     `some_chars_table` VARCHAR(255) NOT NULL,
     `fk_sometable` INT,
-    FOREIGN KEY (`fk_sometable`) REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE,
+    CONSTRAINT `fk_sometabl_sometabl_6efae9bd` FOREIGN KEY (`fk_sometable`) REFERENCES `sometable` (`sometable_id`) ON DELETE CASCADE,
     KEY `sometable_some_ch_115115_idx` (`some_chars_table`)
 ) CHARACTER SET utf8mb4;
 CREATE TABLE IF NOT EXISTS `team` (
     `name` VARCHAR(50) NOT NULL  PRIMARY KEY COMMENT 'The TEAM name (and PK)',
     `manager_id` VARCHAR(50),
-    FOREIGN KEY (`manager_id`) REFERENCES `team` (`name`) ON DELETE CASCADE
+    CONSTRAINT `fk_team_team_9c77cd8f` FOREIGN KEY (`manager_id`) REFERENCES `team` (`name`) ON DELETE CASCADE
 ) CHARACTER SET utf8mb4 COMMENT='The TEAMS!';
 CREATE TABLE IF NOT EXISTS `tournament` (
     `tid` SMALLINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
-    `name` TEXT NOT NULL  COMMENT 'Tournament name',
+    `name` VARCHAR(100) NOT NULL  COMMENT 'Tournament name',
     `created` DATETIME(6) NOT NULL  COMMENT 'Created */\\'`/* datetime',
     KEY `tournament_name_116110_idx` (`name`)
 ) CHARACTER SET utf8mb4 COMMENT='What Tournaments */\\'`/* we have';
 CREATE TABLE IF NOT EXISTS `event` (
     `id` BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT COMMENT 'Event ID',
-    `name` TEXT NOT NULL UNIQUE,
+    `name` TEXT NOT NULL,
     `modified` DATETIME(6) NOT NULL,
     `prize` DECIMAL(10,2),
     `token` VARCHAR(100) NOT NULL UNIQUE COMMENT 'Unique token',
     `tournament_id` SMALLINT NOT NULL COMMENT 'FK to tournament',
-    FOREIGN KEY (`tournament_id`) REFERENCES `tournament` (`tid`) ON DELETE CASCADE
+    CONSTRAINT `fk_event_tourname_51c2b82d` FOREIGN KEY (`tournament_id`) REFERENCES `tournament` (`tid`) ON DELETE CASCADE
 ) CHARACTER SET utf8mb4 COMMENT='This table contains a list of all the events';
 CREATE TABLE IF NOT EXISTS `sometable_self` (
     `backward_sts` INT NOT NULL,
@@ -425,7 +425,6 @@ async def test_schema_safe(self):
     FOREIGN KEY (`event_id`) REFERENCES `event` (`id`) ON DELETE CASCADE,
     FOREIGN KEY (`team_id`) REFERENCES `team` (`name`) ON DELETE CASCADE
 ) CHARACTER SET utf8mb4 COMMENT='How participants relate';
-
 """.strip(),  # noqa
         )
 
@@ -498,7 +497,7 @@ async def test_schema(self):
 COMMENT ON TABLE team IS 'The TEAMS!';
 CREATE TABLE "tournament" (
     "tid" SMALLSERIAL NOT NULL PRIMARY KEY,
-    "name" TEXT NOT NULL,
+    "name" VARCHAR(100) NOT NULL,
     "created" TIMESTAMP NOT NULL
 );
 CREATE INDEX "tournament_name_116110_idx" ON "tournament" (name);
@@ -507,7 +506,7 @@ async def test_schema(self):
 COMMENT ON TABLE tournament IS 'What Tournaments */''`/* we have';
 CREATE TABLE "event" (
     "id" BIGSERIAL NOT NULL PRIMARY KEY,
-    "name" TEXT NOT NULL UNIQUE,
+    "name" TEXT NOT NULL,
     "modified" TIMESTAMP NOT NULL,
     "prize" DECIMAL(10,2),
     "token" VARCHAR(100) NOT NULL UNIQUE,
@@ -559,7 +558,7 @@ async def test_schema_safe(self):
 COMMENT ON TABLE team IS 'The TEAMS!';
 CREATE TABLE IF NOT EXISTS "tournament" (
     "tid" SMALLSERIAL NOT NULL PRIMARY KEY,
-    "name" TEXT NOT NULL,
+    "name" VARCHAR(100) NOT NULL,
     "created" TIMESTAMP NOT NULL
 );
 CREATE INDEX IF NOT EXISTS "tournament_name_116110_idx" ON "tournament" (name);
@@ -568,7 +567,7 @@ async def test_schema_safe(self):
 COMMENT ON TABLE tournament IS 'What Tournaments */''`/* we have';
 CREATE TABLE IF NOT EXISTS "event" (
     "id" BIGSERIAL NOT NULL PRIMARY KEY,
-    "name" TEXT NOT NULL UNIQUE,
+    "name" TEXT NOT NULL,
     "modified" TIMESTAMP NOT NULL,
     "prize" DECIMAL(10,2),
     "token" VARCHAR(100) NOT NULL UNIQUE,

diff --git a/tortoise/__init__.py b/tortoise/__init__.py
@@ -669,4 +669,4 @@ async def do_stuff():
         loop.run_until_complete(Tortoise.close_connections())
 
 
-__version__ = "0.13.9"
+__version__ = "0.13.10"
diff --git a/tortoise/backends/base/schema_generator.py b/tortoise/backends/base/schema_generator.py
@@ -1,4 +1,5 @@
 import logging
+from hashlib import sha256
 from typing import List, Optional, Set  # noqa
 
 from tortoise import fields
@@ -57,7 +58,13 @@ def _create_string(
         ).strip()
 
     def _create_fk_string(
-        self, db_field: str, table: str, field: str, on_delete: str, comment: str
+        self,
+        constraint_name: str,
+        db_field: str,
+        table: str,
+        field: str,
+        on_delete: str,
+        comment: str,
     ) -> str:
         return self.FK_TEMPLATE.format(
             db_field=db_field, table=table, field=field, on_delete=on_delete, comment=comment
@@ -101,11 +108,18 @@ def _get_inner_statements(self) -> List[str]:
     @staticmethod
     def _make_hash(*args: str, length: int) -> str:
         # Hash a set of string values and get a digest of the given length.
+        # TODO: This is super-bad from a cryptographic POV.
+        #  Replace in a major version to minimise unexpected breakages.
         letters = []  # type: List[str]
         for i_th_letters in zip(*args):
             letters.extend(i_th_letters)
         return "".join([str(ord(letter)) for letter in letters])[:length]
 
+    @staticmethod
+    def _make_hash2(*args: str, length: int) -> str:
+        # Hash a set of string values and get a digest of the given length.
+        return sha256(";".join(args).encode("utf-8")).hexdigest()[:length]
+
     def _generate_index_name(self, model, field_names: List[str]) -> str:
         # NOTE: for compatibility, index name should not be longer than 30
         # characters (Oracle limit).
@@ -118,6 +132,17 @@ def _generate_index_name(self, model, field_names: List[str]) -> str:
         )
         return index_name
 
+    def _generate_fk_name(self, from_table, from_field, to_table, to_field) -> str:
+        # NOTE: for compatibility, index name should not be longer than 30
+        # characters (Oracle limit).
+        # That's why we slice some of the strings here.
+        index_name = "fk_{f}_{t}_{h}".format(
+            f=from_table[:8],
+            t=to_table[:8],
+            h=self._make_hash2(from_table, from_field, to_table, to_field, length=8),
+        )
+        return index_name
+
     def _get_index_sql(self, model, field_names: List[str], safe: bool) -> str:
         return self.INDEX_CREATE_TEMPLATE.format(
             exists="IF NOT EXISTS " if safe else "",
@@ -188,6 +213,12 @@ def _get_table_sql(self, model, safe=True) -> dict:
                     is_pk=field_object.pk,
                     comment="",
                 ) + self._create_fk_string(
+                    constraint_name=self._generate_fk_name(
+                        model._meta.table,
+                        db_field,
+                        field_object.reference.type._meta.table,
+                        field_object.reference.type._meta.db_pk_field,
+                    ),
                     db_field=db_field,
                     table=field_object.reference.type._meta.table,
                     field=field_object.reference.type._meta.db_pk_field,

diff --git a/tortoise/backends/mysql/schema_generator.py b/tortoise/backends/mysql/schema_generator.py
@@ -9,7 +9,8 @@ class MySQLSchemaGenerator(BaseSchemaGenerator):
     INDEX_CREATE_TEMPLATE = "KEY `{index_name}` ({fields})"
     FIELD_TEMPLATE = "`{name}` {type} {nullable} {unique}{primary}{comment}"
     FK_TEMPLATE = (
-        "FOREIGN KEY (`{db_field}`) REFERENCES `{table}` (`{field}`) ON DELETE {on_delete}"
+        "CONSTRAINT `{constraint_name}` FOREIGN KEY (`{db_field}`)"
+        " REFERENCES `{table}` (`{field}`) ON DELETE {on_delete}"
     )
     M2M_TABLE_TEMPLATE = (
         "CREATE TABLE {exists}`{table_name}` (\n"
@@ -66,11 +67,21 @@ def _get_index_sql(self, model, field_names: List[str], safe: bool) -> str:
         return ""
 
     def _create_fk_string(
-        self, db_field: str, table: str, field: str, on_delete: str, comment: str
+        self,
+        constraint_name: str,
+        db_field: str,
+        table: str,
+        field: str,
+        on_delete: str,
+        comment: str,
     ) -> str:
         self._foreign_keys.append(
             self.FK_TEMPLATE.format(
-                db_field=db_field, table=table, field=field, on_delete=on_delete
+                constraint_name=constraint_name,
+                db_field=db_field,
+                table=table,
+                field=field,
+                on_delete=on_delete,
             )
         )
         return comment