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What is the difference between BIT and TINYINT in MySQL?
... 64. The default is 1 if M is omitted.
This data type was added in MySQL
5.0.3 for MyISAM, and extended in 5.0.5 to MEMORY, InnoDB, BDB, and NDBCLUSTER. Before 5.0.3, BIT is a
synonym for TINYINT(1).
TINYINT[(M)] [UNSIGNED] [ZEROFILL]
A very small integer. The signed range
is -128 ...
What is the difference between persist() and merge() in JPA and Hibernate?
...e assigned generator, using merge instead of persist can cause a redundant SQL statement, therefore affecting performance.
Also, calling merge for managed entities is also a mistake since managed entities are automatically managed by Hibernate and their state is synchronized with the database recor...
Why is Lisp used for AI? [closed]
... minutes of macro work this week, I implemented an ad-hoc buggy version of SQL Select. It goes like this: (query SELECT * FROM dataset WHERE expr).
– Paul Nathan
Nov 12 '11 at 20:08
...
Creation timestamp and last update timestamp with Hibernate and MySQL
...
I would do this using a MySQL trigger so that even if the full entity is not saved or is modified by any external application or manual query, it'll still update these fields.
– Webnet
Jul 25 '13 at 12:09
...
Automatically create an Enum based on values in a database lookup table?
...one also ; ), let the advanced students present it ...
So here is the DDL SQL for the table :
USE [ocms_dev]
GO
CREATE TABLE [dbo].[Role](
[RoleId] [int] IDENTITY(1,1) NOT NULL,
[RoleName] [varchar](50) NULL
) ON [PRIMARY]
So here is the console program producing the dll:
using S...
Why use 'virtual' for class properties in Entity Framework model definitions?
...rty allows you to denote it as the equivalent of a nullable Foreign Key in SQL. You do not HAVE to eagerly join every keyed table when performing a query, but when you need the information -- it becomes demand-driven.
I also mentioned nullable because many navigation properties are not relevant ...
how do you filter pandas dataframes by multiple columns
...
However, I think the query syntax is neater and close to SQL, which makes it nice for data since. The chery on the cake is that it's faster with many rows :)
– csgroen
Aug 27 at 15:58
...
How can I measure the speed of code written in PHP? [closed]
...ink the DB request doesn't take much time !
This should be profiled on the SQL server, not PHP, so...
Hope this is helpful :-)
Have fun !
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How do I automatically sort a has_many relationship in Rails?
...cantly slower (and use a lot more memory) than doing your ordering through SQL/ActiveRecord.
If you are doing something where adding a default order is cumbersome for some reason or you want to override your default in certain cases, it is trivial to specify it in the fetching action itself:
sort...
How to implement one-to-one, one-to-many and many-to-many relationships while designing tables?
...
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