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How to prepend a string to a column value in MySQL?
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Many string update functions in MySQL seems to be working like this:
If one argument is null, then concatenation or other functions return null too.
So, to update a field with null value, first set it to a non-null value, such as ''
For example:
update ta...
ZMQ: 基本原理 - 开源 & Github - 清泛网 - 专注C++内核技术
...的一个。 本文的目的是解释ØMQ架构的基本概念，它们是如何组合起来的，以及它们被如此设计的原因。 拓扑 拓扑是ØMQ最主要的概念，除非你知道“拓扑”代表什么，否则将与其他概念混淆更难理解，甚至理解不当。 按...
Is there documentation for the Rails column types?
...ded by Rails mostly for compatibility with database systems. For instance, MySQL's TIMESTAMP datatype is stored as a unix timestamp. Its valid range goes from 1970 to 2038, and the time is stored as the number of seconds that have elapsed since the last epoch, which is supposedly standard, but in pr...
Real escape string and PDO [duplicate]
I'm using PDO after migrating away from the mysql library. What do I use in place of the old real_escape_string function?
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How Can I Set the Default Value of a Timestamp Column to the Current Timestamp with Laravel Migratio
...e->timestamp('created_at')->useCurrent();
Back to the question, on MySQL you could also use the ON UPDATE clause through DB::raw():
$table->timestamp('updated_at')->default(DB::raw('CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP'));
Gotchas
MySQL
Starting with MySQL 5.7, 0000-00-00...
Replace Default Null Values Returned From Left Outer Join
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If it is MySQL, IsNull should be replaced with 'IFNULL'. Thanks.
– Dhanushka
Jul 14 '14 at 6:54
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一文了解大数据领域创业的机会与方向 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...据告诉我们，究竟什么是大数据，大数据行业的创业机会如何，未来的创业方向又有哪些。
接触大数据，了解这个行业已经有两年多了，每天都在阅读大量的关于大数据的文献资料和技术文章。如果你要问我什么是大数据？以...
MySQL search and replace some text in a field
What MySQL query will do a text search and replace in one particular field in a table?
7 Answers
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MySQL: multiple tables or one table with many columns?
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Recently I was faced with this same problem, because MySQL InnoDB tables have a relatively small length limit (~8000 bytes). In my problem table (data from very lengthy insurance forms, more than 100 columns) we have multiple varchar columns, all UTF8. So we easily filled the ~...
What are the differences between utf8_general_ci and utf8_unicode_ci? [duplicate]
I've got two options for unicode that look promising for a mysql database.
2 Answers
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