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MySQL IF NOT NULL, then display 1, else display 0
... NOT NULL) AS addressexists
This works because TRUE is displayed as 1 in MySQL and FALSE as 0.
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mysql - how many columns is too many?
...tables with many rows, modifying the indexes can take a very long time, as MySQL needs to rebuild all of the indexes in the table. Having the indexes split over several table could make that faster.
Depending on your queries and column types, MySQL could be writing temporary tables (used in more co...
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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那些我印象深刻的建议和教诲 - 杂谈 - 清泛网 - 专注C/C++及内核技术
...负有心人”和“蠢”之间可能连窗户纸都没有，只看个人如何面对了。
多用Google吧
我工作的第一天，项目经理把我叫去说：给你们讲讲JUnit, SVN，Ant, JBuilder的用法，明天开始用。这四样东西我以前都没有接触过，第一反应就是...
PDO closing connection
Just a rather simple question with regards to PDO compared to MySQLi.
5 Answers
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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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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...