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MySQL一次主从数据不一致的问题解决过程 - 数据库(内核) - 清泛网 - 专注C/...
...，虽然对主库的使用没有影响，但是那么大的数据量，对性能，网络影响有点大，数据丢失的应该很少
2 主库dump数据，锁库，然后同步，不好。 影响业务使用
3 percona-toolkit 中的工具来校验和同步，从介绍上来看是符合现在...
Rails where condition using NOT NIL
... should use references here as well, otherwise you may end up with invalid SQL.
Foo.includes(:bar)
.references(:bar)
.merge(Bar.where.not(id: nil))
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Code-first vs Model/Database-first [closed]
...t
IMHO popular if you are designer fan (= you don't like writing code or SQL).
You will "draw" your model and let workflow generate your database script and T4 template generate your POCO entities. You will lose part of the control on both your entities and database but for small easy projects you...
IDENTITY_INSERT is set to OFF - How to turn it ON?
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Reminder
SQL Server only allows one table to have IDENTITY_INSERT property set to ON.
This does not work:
SET IDENTITY_INSERT TableA ON
SET IDENTITY_INSERT TableB ON
... INSERT ON TableA ...
... INSERT ON TableB ...
SET IDENTITY_INS...
When/Why to use Cascading in SQL Server?
When setting up foreign keys in SQL Server, under what circumstances should you have it cascade on delete or update, and what is the reasoning behind it?
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Joins are for lazy people?
...ntly had a discussion with another developer who claimed to me that JOINs (SQL) are useless. This is technically true but he added that using joins is less efficient than making several requests and link tables in the code (C# or Java).
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Grepping a huge file (80GB) any way to speed it up?
... command becomes:
LC_ALL=C fgrep -A 5 -B 5 'db_pd.Clients' eightygigsfile.sql
It will also be faster if you copy your file to RAM disk.
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PHP/MySQL insert row then get 'id'
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$link = mysqli_connect('127.0.0.1', 'my_user', 'my_pass', 'my_db');
mysqli_query($link, "INSERT INTO mytable (1, 2, 3, 'blah')");
$id = mysqli_insert_id($link);
See mysqli_insert_id().
Whatever you do, don't insert and then do a "SE...
Delete all records in a table of MYSQL in phpMyAdmin
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Go to the Sql tab run one of the below query:
delete from tableName;
Delete: will delete all rows from your table. Next insert will take next auto increment id.
or
truncate tableName;
Truncate: will also delete the rows from yo...
Find the number of columns in a table
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In MySQL land (tagged in the question)... A MySQL database is equivalent to a schema in ANSI SQL and the table_catalog is always def
– Steve Buzonas
Mar 5 '14 at 18:17
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