带有 Alembic 的存储过程:MySQL 语法错误 [英] Stored procedure with Alembic: MySQL Syntax Error

问题描述

我正在使用 Alembic 将存储过程加载到 MySQL 数据库中.遵循 cookbook，我能够创建所需的对象来创建和删除程序，流程.现在我想升级版本以实际加载过程，我在 DELIMITER $$ 附近获得了 SQL 语法，这是过程定义所需的.我还尝试删除 DELIMITER 并替换 AS 以启动程序，但这也不起作用.我什至尝试了食谱中的简单示例函数，但这也在 $ 附近给了我相同的语法错误.

I am using Alembic to load a stored procedure into the MySQL database. Following the cookbook, I was able to create the required objects for creating and dropping the procedure. Now that I want to upgrade the version to actually load the procedure, I am getting SQL syntax near the DELIMITER $$ which I need for procedure definition. I have also tried to remove the DELIMITER and replace AS for starting the procedure, but that didn't work either. I even tried the simple example function in the cookbook, but that also gave me the same syntax error near $.

class ReplaceableObject:
    def __init__(self, name, sqltext):
        self.name = name
        self.sqltext = sqltext


class ReversibleOp(MigrateOperation):
    def __init__(self, target):
        self.target = target

    @classmethod
    def invoke_for_target(cls, operations, target):
        op = cls(target)
        return operations.invoke(op)

    def reverse(self):
        raise NotImplementedError()

    @classmethod
    def _get_object_from_version(cls, operations, ident):
        version, objname = ident.split(".")

        module = operations.get_context().script.get_revision(version).module
        obj = getattr(module, objname)
        return obj

    @classmethod
    def replace(cls, operations, target, replaces=None, replace_with=None):

        if replaces:
            old_obj = cls._get_object_from_version(operations, replaces)
            drop_old = cls(old_obj).reverse()
            create_new = cls(target)
        elif replace_with:
            old_obj = cls._get_object_from_version(operations, replace_with)
            drop_old = cls(target).reverse()
            create_new = cls(old_obj)
        else:
            raise TypeError("replaces or replace_with is required")

        operations.invoke(drop_old)
        operations.invoke(create_new)


@Operations.register_operation("create_sp", "invoke_for_target")
@Operations.register_operation("replace_sp", "replace")
class CreateSPOp(ReversibleOp):
    def reverse(self):
        return DropSPOp(self.target)


@Operations.register_operation("drop_sp", "invoke_for_target")
class DropSPOp(ReversibleOp):
    def reverse(self):
        return CreateSPOp(self.target)


@Operations.implementation_for(CreateSPOp)
def create_sp(operations, operation):
    operations.execute(
        """
        DELIMITER $$
        CREATE PROCEDURE %s %s
        DELIMITER ;
        """ % (
            operation.target.name, operation.target.sqltext
        )
    )


@Operations.implementation_for(DropSPOp)
def drop_sp(operations, operation):
    operations.execute("DROP PROCEDURE IF EXISTS %s" % operation.target.name)

这就是我尝试创建它的方式:

And this is how I'm trying to create it:

my_procedure = ReplaceableObject(
    "my_procedure(IN arg1 TEXT, IN arg2 TEXT, OUT res TEXT)",
    """
    BEGIN
        -- procedure implementation
    END $$   
    """
)

def upgrade():
    op.create_sp(my_procedure)

def downgrade():
    op.drop_sp(my_procedure)

这是错误(我使用 pymysql 作为客户端):

And this is the error (I'm using pymysql as client):

sqlalchemy.exc.ProgrammingError: (pymysql.err.ProgrammingError) (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER $$\n        CREATE PROCEDURE my_procedure(IN arg1 TEXT, IN arg2 TEXT, OU' at line 1")

推荐答案

您不需要 DELIMITER，除非在支持一系列分号分隔语句的环境中 — MySQL 客户端.

You don't need DELIMITER except in an environment that supports a series of semicolon-separated statements — the MySQL client.

其实DELIMITER命令就是一个mysql 客户端内建，并且不被 MySQL 服务器识别.

In fact, the DELIMITER command is a mysql client builtin, and it's not recognized by the MySQL Server.

在通过 API 向 MySQL 服务器提交语句时，您不得使用 DELIMITER，即使它是 CREATE PROCEDURE.

You must not use DELIMITER when submitting statements to the MySQL Server through an API, even if it's CREATE PROCEDURE.

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