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How do I execute inserts and updates in an Alembic upgrade script?
...rent connection, and make a session with it.
Or use bind.execute() to use SQLAlchemy's lower level to write SQL queries directly. This is useful for simple migrations.
Use the models and session as you normally would in your application.
"""create teams table
Revision ID: 169ad57156f0
Revises...
Does PostgreSQL support “accent insensitive” collations?
In Microsoft SQL Server, it's possible to specify an "accent insensitive" collation (for a database, table or column), which means that it's possible for a query like
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CASCADE DELETE just once
I have a Postgresql database on which I want to do a few cascading deletes. However, the tables aren't set up with the ON DELETE CASCADE rule. Is there any way I can perform a delete and tell Postgresql to cascade it just this once? Something equivalent to
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What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
...lly, a lot of dbms have been quite poor when it comes to handling joins (MySQL being a particularly noteworthy example). So n+1 has, often, been notably faster than a join. And then there are ways to improve on n+1 but still without needing a join, which is what the original problem relates to.
How...
I need to generate uuid for my rails application. What are the options(gems) I have? [duplicate]
... UUID has RFC! This will break any UUID validation (like in PostgreSQL)
– kixorz
Feb 10 '14 at 8:05
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Alter a MySQL column to be AUTO_INCREMENT
...ry key column AUTO_INCREMENT after the fact. I have tried the following SQL, but got a syntax error notification.
19 Ans...
How do I enable MSDTC on SQL Server?
Is this even a valid question? I have a .NET Windows app that is using MSTDC and it is throwing an exception:
6 Answers
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What is the maximum length of a table name in Oracle?
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With standard SQL you can also determine the lengths by querying the table: select * from all_tab_columns where table_name = 'ALL_TAB_COLUMNS';
– JustinKSU
Mar 11 '16 at 23:18
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Best way to check if object exists in Entity Framework?
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If you don't want to execute SQL directly, the best way is to use Any(). This is because Any() will return as soon as it finds a match. Another option is Count(), but this might need to check every row before returning.
Here's an example of how to use i...
How to generate a new Guid in stored procedure?
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With SQL Server you can use the function NEWID. You're using C# so I assume that you're using SQL Server. I'm sure other database system have similar functions.
select NEWID()
If you're using Oracle then you can use the SYS_GUI...