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MySQL - length() vs char_length()
...ore accurately UTF-16LE) is what Windows misleadingly calls “Unicode”. MySQL doesn't support UTF-16; instead the usual approach for putting Unicode strings in it is to use UTF-8.
– bobince
Nov 14 '09 at 14:20
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PDO closing connection
Just a rather simple question with regards to PDO compared to MySQLi.
5 Answers
5
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MySQL ON DUPLICATE KEY UPDATE for multiple rows insert in single query
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INSERT INTO ... ON DUPLICATE KEY UPDATE will only work for MYSQL, not for SQL Server.
for SQL server, the way to work around this is to first declare a temp table, insert value to that temp table, and then use MERGE
Like this:
declare @Source table
(
name varchar(30),
age decimal(...
MySQL - How to select data by string length
Is there a MySQL function to do this (of course instead of string_length )?
6 Answers
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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 Select all columns from one table and some from another table
...mns from one table and just some columns from another table using JOIN? In MySQL.
4 Answers
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MySQL foreign key constraints, cascade delete
... When creating the tables, you need to specify InnoDB or another MySQL engine that's capable of CASCADE operations. Otherwise the MySQL default, MyISAM, will be used and MyISAM does not support CASCADE operations. To do this, just add ENGINE InnoDB before the last ;.
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Are there disadvantages to using a generic varchar(255) for all text-based fields?
...ould always store 255 characters.
But since you tagged this question with MySQL, I'll mention a MySQL-specific tip: as rows are copied from the storage engine layer to the SQL layer, VARCHAR fields are converted to CHAR to gain the advantage of working with fixed-width rows. So the strings in mem...
浅谈TCP优化 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...里就不一一说明了，有兴趣的读者可以自行查阅。
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如何调整「rwnd」到一个合理值
有很多人都遇到过网络传输速度过慢的问题，比如说明明是百兆网络，其最大传输数据的理论值怎么着也得有个十兆，但是实际情况却相距...
MySQL Results as comma separated list
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The intent is fine and MySQL will allow this, but be careful (generally) with your use of GROUP BY. The items in the select list need to be valid aggregates in the context of the GROUP BY clause. In this case, p.name is not strictly valid. Any d...