Thank you, Mike, but aren't I using the correct dialect with this
create_engine() command?
* qry_engine = create_engine('mysql+pymysql://' + db_uid + ':' +
db_pw + '@' + db_addr, connect_args=connect_args,
pool_recycle=3600, echo=False, future=True)*
Or, am I missing something? (BTW, I'm using core, not ORM).
Thanks again!
Ben
On Friday, May 12, 2023 at 4:48:45 PM UTC-4 Mike Bayer wrote:
>
>
> On Fri, May 12, 2023, at 4:30 PM, Benjamin Taub wrote:
>
> I have code that worked under SQLAlchemy 1.4 but recently upgraded to 2. I
> am using the add_columns() method to add columns to an existing SQL
> statement. The resultant queries sometimes, but not always, crash. I
> believe the issue happens when the schema/database name (I'm using MySQL)
> starts with a number. When the schema name starts with a letter, the result
> runs fine. However, when it starts with a number, the query double-quotes
> the schema name, causing the query to crash.
>
> Here is an example...
> My code: *sql = sql.add_columns(self.tbl.c[field])*
>
> When the schema holding self.tbl.c[field] starts with a letter
> (c6961a19b7ed031ce902f056c725b3e3), the following SQL is generated:
>
> *SELECT NULL AS "Application Id", NULL AS "First Name", NULL AS "Last
> Name", NULL AS "Email",
> c6961a19b7ed031ce902f056c725b3e3.t_31392eb2e6980f4d5082b7861182f2b4.master_key
>
> FROM c6961a19b7ed031ce902f056c725b3e3.t_31392eb2e6980f4d5082b7861182f2b4*
>
> However, when the schema name starts with a number
> (283ac7717fe770c5ed6d425c0c739cba), the following SQL results:
>
> *SELECT NULL AS "Application Id", NULL AS "First Name", NULL AS "Last
> Name", NULL AS "Email",
> "283ac7717fe770c5ed6d425c0c739cba".t_59a33cbea3617986d810e9fbae60ba19.master_key
>
> FROM "283ac7717fe770c5ed6d425c0c739cba".t_59a33cbea3617986d810e9fbae60ba19*
>
> Note the double quotes around the schema name. This second SQL crashes as
> invalid. Back quotes (`) would probably work fine in this situation, and
> could be helpful, but double quotes (") are, I think, the cause of my
> problem.
>
> Is there some parameter or assumption that I'm not understanding, or did I
> find a bug?
>
>
> The quoting, if it were the correct quoting format, should be fine. As
> to why it's the quote char and not the backtick, are you compiling these
> queries manually? You would want to make sure a MySQL dialect is in use,
> which would be using backticks for quoting, unless that dialect were
> initialized against a MySQL database that has ANSI_QUOTES set.
>
> TL;DR quoting is a new thing here but SQLAlchemy should render the correct
> quotes when used with the MySQL dialect.
>
> Here's a demo:
>
> from sqlalchemy import Column
> from sqlalchemy import create_engine
> from sqlalchemy import Integer
> from sqlalchemy import select
> from sqlalchemy import String
> from sqlalchemy.orm import declarative_base
> Base = declarative_base()
>
>
> class A(Base):
> __tablename__ = 't_59a33cbea3617986d810e9fbae60ba19'
>
> __table_args__ = {
> "schema": "283ac7717fe770c5ed6d425c0c739cba"
> }
> id = Column(Integer, primary_key=True)
> data = Column(String)
>
> e = create_engine("mysql://")
>
> stmt = select(A)
>
> print(stmt.compile(e))
>
> output:
>
> SELECT `283ac7717fe770c5ed6d425c0c739cba`.
> t_59a33cbea3617986d810e9fbae60ba19.id,
> `283ac7717fe770c5ed6d425c0c739cba`.t_59a33cbea3617986d810e9fbae60ba19.data
> FROM `283ac7717fe770c5ed6d425c0c739cba`.t_59a33cbea3617986d810e9fbae60ba19
>
>
>
>
> Thank you!
> Ben
>
>
>
> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
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> To post example code, please provide an MCVE: Minimal, Complete, and
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SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
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