mysql> select @@version;
+-----------+
| @@version |
+-----------+
| 8.0.20    |
+-----------+
python -V
Python 2.7.12

我使用下面sqlalchemy输出的sql，创建表是可以的。

CREATE TABLE images (
    created_at DATETIME,
    updated_at DATETIME,
    deleted_at DATETIME,
    deleted INTEGER,
    platform_id VARCHAR(36) NOT NULL,
    image_id VARCHAR(36) NOT NULL,
    PRIMARY KEY (platform_id, image_id)
);


CREATE TABLE flavors (
    created_at DATETIME,
    updated_at DATETIME,
    deleted_at DATETIME,
    deleted INTEGER,
    platform_id VARCHAR(36) NOT NULL,
    flavor_id VARCHAR(36) NOT NULL,
    PRIMARY KEY (platform_id, flavor_id)
);


CREATE TABLE security_groups (
    created_at DATETIME,
    updated_at DATETIME,
    deleted_at DATETIME,
    deleted INTEGER,
    platform_id VARCHAR(36) NOT NULL,
    name VARCHAR(255) NOT NULL,
    tenant_id VARCHAR(36),
    user_id VARCHAR(36),
    PRIMARY KEY (platform_id, name)
);


CREATE TABLE instances (
    created_at DATETIME,
    updated_at DATETIME,
    deleted_at DATETIME,
    deleted INTEGER,
    flavor_id VARCHAR(36),
    image_id VARCHAR(36),
    security_group_name VARCHAR(255),
    platform_id VARCHAR(36) NOT NULL,
    uuid VARCHAR(36) NOT NULL,
    user_id VARCHAR(36),
    tenant_id VARCHAR(36),
    `accessIPv4` VARCHAR(255),
    `accessIPv6` VARCHAR(255),
    progress INTEGER,
    config_drive BOOL,
    status VARCHAR(255),
    `hostId` VARCHAR(255),
    key_name VARCHAR(255),
    name VARCHAR(255),
    updated DATETIME,
    created DATETIME,
    launched_at DATETIME,
    terminated_at DATETIME,
    task_state VARCHAR(255),
    vm_state VARCHAR(255),
    instance_name VARCHAR(255),
    `diskConfig` VARCHAR(255),
    power_state INTEGER,
    availability_zone VARCHAR(255),
    host VARCHAR(255),
    hypervisor_hostname VARCHAR(255),
    PRIMARY KEY (platform_id, uuid),
    CHECK (config_drive IN (0, 1))
);

ALTER TABLE instances ADD CONSTRAINT flavor_instances_fk FOREIGN KEY(platform_id, flavor_id) REFERENCES flavors (platform_id, flavor_id)

但当我使用迁移脚本时，它会失败，并显示以下错误消息

出现错误：

Traceback（最近一次调用最后）：File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/Engine/base.py"，第1277行，_execute_context游标，语句，参数，上下文File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/Engine/default.py"，第593行，在do_executecursor.execute（语句，参数）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/cursors.py"，第163行，在执行结果=自我。_query（查询）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/cursors.py"，第321行，在_queryconn.query（q）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/connections.py"，第505行，在查询自我中。_affected_rows=自我。_read_query_result（unbu据称）File"/root/。Virtualenvs/cpmsv2/lib/python3.7/site-包/pymysql/connections.py"，第724行，_read_query_resultresult.read（）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/connections.py"，第1069行，first_packet=self.connection._read_packet（）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/connections.py"，第676行，_read_packetpacket.raise_for_error（）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/protocol.py"，第223行，在raise_for_errorerr.raise_mysql_exception（自己。_data）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-pack/pymysql/err.py"，第107行，在raise_mysql_exception中提高错误类（errno，errval）pymysql.err.操作错误：（3780，引用列'platform_id'和引用外键约束flavor_instances_fk中的列platform_id不兼容。"）

上述异常是以下异常的直接原因：

Traceback（最近调用最后一次）：File"/root/work/cpmsv2/cpmsv2/test/功能/db/test_migrate.py"，第118行，名称为='flavor_instances_fk'）。在创建自。__do_imports（“约束生成器”，*a，**kw）文件“/root/. Virtualenvs/cpmsv2/lib/python3.7/site-pack/迁移/变更集/constraint.py”，第32行，__do_importsrun_single_visitor（引擎，visitorcall，自，*a，**kw）文件”/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/迁移/变更集/数据库/visitor.py"，第85行，run_single_visitorfn（元素，**kwargs）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/迁移/变更集/ansisql.py"，第285行，visit_migrate_foreign_key_constraint。_visit_constraint（*p，**k）文件"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-pack/迁移/变更集/ansisql.py"，第297行，_visit_constraintself.execute（）文件"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-Packes/迁移/变更集/ansisql.py"，第44行，正在执行返回self.connection.execute（self.buffer.getvalue（））File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-pack/sqlalChemy/Engine/base.py"，第1003行，在执行返回self.execute_text（对象，多参数，参数）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/引擎/base.py"，第1178行，_execute_text参数，File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/引擎/base.py"，第1317行，execute_contexte，语句，参数，光标，上下文File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/引擎/base.py"，第1511行，handle_dbapi_exceptionsqlalchemy_exception，with_traceback=exc_info[2]，from=e File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/util/compat.py"，第182行，在提升提升中异常文件"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/引擎/base.py"，第1277行，_execute_context光标、语句、参数、上下文文件"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/sqlalChemy/引擎/default.py"，第593行，在do_executecursor.execute（语句，参数）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/cursors.py"，第163行，在执行结果=自己。_query（查询）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/cursors. py"，第321行，在_queryconn. Query（q）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/pymysql/连接. py"中，第505行，在查询自.中。_affected_rows=自._read_query_result（unbu0007=unbu0007）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/pymysql/连接. py"，第724行，在_read_query_result结果. read（）File"中/root/.virtualenvs/cpmsv2/lib/python3.7/site-packages/pymysql/connections.py"，第1069行，在_read_packet数据包中读取first_packet=自己。连接。_read_packet（）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/pymysql/连接. py"，第676行。raise_for_error（）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-包/pymysql/_data）File"/root/. Virtualenvs/cpmsv2/lib/python3.7/site-pack/pymysql/err. py"，第223行，在raise_for_errorerr.raise_mysql_exception（自己的.constraint.py）File"/root/. viralenvs/cpmsv2/lib/python3.7/site-包/pymysql/err. py"，第107行，在raise_mysql_exception提高errorclass（errno，errval）sqlalchey. exc。操作错误：（pymysql. err.（3780，"引用列'platform_id'和外键约束'flavor_instances_fk'中引用列'platform_id'不兼容。"）[SQL： ALTER TABLE实例ADD CONSTRAINTflavor_instances_fkFOREIGN KEY（platform_id，flavor_id）REFERENCES口味（platform_id，flavor_id）]（此错误的背景：超文本协议：//sqlalche. me/e/13/e3q8）上面引用了详细信息表。（有关此错误的背景信息：超文本传输协议：//sqlalche. me/e/13/e3q8）

可以重现错误的最小代码段如下所示

from sqlalchemy import create_engine
from sqlalchemy import Boolean, Column, DateTime, Enum, Float
from sqlalchemy import dialects
from sqlalchemy import ForeignKey, ForeignKeyConstraint, Index, Integer, MetaData, PrimaryKeyConstraint, String, Table # noqa
from sqlalchemy import Text

connection_string = 'your_connect_string'
engine = create_engine(connection_string, echo=True)
meta = MetaData()
meta.bind = engine
tables = []


instances = Table(
    'instances', meta,
    # Created by TimestampMixin
    Column('created_at', DateTime),
    Column('updated_at', DateTime),
    # Created by SoftDeleteMixin
    Column('deleted_at', DateTime),
    Column('deleted', Integer),

    Column('flavor_id', String(36)),
    Column('image_id', String(36)),
    Column('security_group_name', String(255)),

    Column('platform_id', String(36), primary_key=True),
    Column('uuid', String(36), primary_key=True),
    Column('user_id', String(36)),
    Column('tenant_id', String(36)),


    Column('accessIPv4', String(255)),
    Column('accessIPv6', String(255)),
    Column('progress', Integer),
    Column('config_drive', Boolean),
    Column('status', String(255)),
    Column('hostId', String(255)),
    Column('key_name', String(255)),
    Column('name', String(255)),

    Column('updated', DateTime),
    Column('created', DateTime),
    Column('launched_at', DateTime),
    Column('terminated_at', DateTime),

    Column('task_state', String(255)),
    Column('vm_state', String(255)),
    Column('instance_name', String(255)),
    Column('diskConfig', String(255)),
    Column('power_state', Integer),
    Column('availability_zone', String(255)),
    Column('host', String(255)),
    Column('hypervisor_hostname', String(255)),
    mysql_engine='InnoDB',
    mysql_charset='utf8'
)


images = Table(
    'images', meta,
    # Created by TimestampMixin
    Column('created_at', DateTime),
    Column('updated_at', DateTime),
    # Created by SoftDeleteMixin
    Column('deleted_at', DateTime),
    Column('deleted', Integer),

    Column('platform_id', String(36), primary_key=True),
    Column('image_id', String(36), primary_key=True),
)


flavors = Table(
    'flavors', meta,
    # Created by TimestampMixin
    Column('created_at', DateTime),
    Column('updated_at', DateTime),
    # Created by SoftDeleteMixin
    Column('deleted_at', DateTime),
    Column('deleted', Integer),

    Column('platform_id', String(36), primary_key=True),
    Column('flavor_id', String(36), primary_key=True),
)


security_groups = Table(
    'security_groups', meta,
    # Created by TimestampMixin
    Column('created_at', DateTime),
    Column('updated_at', DateTime),
    # Created by SoftDeleteMixin
    Column('deleted_at', DateTime),
    Column('deleted', Integer),

    Column('platform_id', String(36), primary_key=True),
    Column('name', String(255), primary_key=True),

    Column('tenant_id', String(36)),
    Column('user_id', String(36)),
)


tables.append(images)
tables.append(flavors)
tables.append(security_groups)
tables.append(instances)

meta.create_all(tables=tables)
from migrate import ForeignKeyConstraint, UniqueConstraint

# UniqueConstraint(instances.c.platform_id, instances.c.flavor_id,
#                  name='platform_flavor_constraint').create()
ForeignKeyConstraint([instances.c.platform_id, instances.c.flavor_id],
                     [flavors.c.platform_id, flavors.c.flavor_id],
                     name='flavor_instances_fk').create()
ForeignKeyConstraint([instances.c.platform_id, instances.c.image_id],
                     [images.c.platform_id, images.c.image_id],
                     name='image_instances_fk').create()
ForeignKeyConstraint([instances.c.platform_id, instances.c.security_group_name], # noqa
                     [security_groups.c.platform_id, security_groups.c.name],
                     name='sec_groups_instances_fk').create() # noqa