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Sqlite primary key on multiple columns
What is the syntax for specifying a primary key on more than 1 column in SQLITE ?
9 Answers
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Return 0 if field is null in MySQL
In MySQL, is there a way to set the "total" fields to zero if they are NULL?
5 Answers
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Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign
...the issue. Removing this section and keeping the rest will still print the SQLite error being generated, which will note the column that has the problem.
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余佳文公开道歉： “一亿分红”本质上是吹嘘炒作 - 资讯 - 清泛网 - 专注C/...
...博，略有删节)
要变成商业领袖，一定要说话算数
无论如何，如果你想要创业，你得是第一把手，最后要变成领袖人物，一定要在这个公司说话算数，为这个公司制订理想、目标、价值观。如果没有这些指导的话，有时候有负...
ActiveRecord: List columns in table from console
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If you are comfortable with SQL commands, you can enter your app's folder and run rails db, which is a brief form of rails dbconsole. It will enter the shell of your database, whether it is sqlite or mysql.
Then, you can query the table columns using...
ALTER TABLE to add a composite primary key
...table you will get an error when trying to drop it. In some versions of mysql the error message there was malformed (as of 5.5.17, this error message is still
alter table parent drop column id;
ERROR 1025 (HY000): Error on rename of
'./test/#sql-a04_b' to './test/parent' (errno: 150).
If you wa...
When and why are database joins expensive?
...x strategy is available to the optimiser.
I used to be smarter than the MSSQL optimiser. That changed two versions ago. Now it generally teaches me. It is, in a very real sense, an expert system, codifying all the wisdom of many very clever people in a domain sufficiently closed that a rule-based s...
Querying data by joining two tables in two database on different servers
...ID
Once the link is established, you can also use OPENQUERY to execute a SQL statement on the remote server and transfer only the data back to you. This can be a bit faster, and it will let the remote server optimize your query. If you cache the data in a temporary (or in-memory) table on DB1 in...
携程遭超长宕机：内部数据管理恐存严重漏洞 - 资讯 - 清泛网 - 专注C/C++及内核技术
...疑似携程员工聊天记录显示，目前携程发布系统仍然无法使用，数据仍然被持续删除中。但纽约时报专栏作家李成东在微博上表示，携程正在重建缓存，估计3小时内回复，原因据说是内部离职员工报复。
360安全专家林伟也表示...
Get the Query Executed in Laravel 3/4
How can I retrieve the raw executed SQL query in Laravel 3/4 using Laravel Query Builder or Eloquent ORM?
20 Answers
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