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What is this operator in MySQL?
...ard and therefore supported on other databases, unlike <=>, which is MySQL-specific.
You can think of them as specialisations of MySQL's <=>:
'a' IS NULL ==> 'a' <=> NULL
'a' IS NOT NULL ==> NOT('a' <=> NULL)
Based on this, your particular query (fragment) can be c...
String concatenation in Ruby
...;< but that is not the usual way
With string interpolation
source = "#{ROOT_DIR}/#{project}/App.config"
with +
source = "#{ROOT_DIR}/" + project + "/App.config"
The second method seems to be more efficient in term of memory/speed from what I've seen (not measured though). All three methods ...
MySQL select 10 random rows from 600K rows fast
...imple, to gaps, to non-uniform with gaps.
http://jan.kneschke.de/projects/mysql/order-by-rand/
For most general case, here is how you do it:
SELECT name
FROM random AS r1 JOIN
(SELECT CEIL(RAND() *
(SELECT MAX(id)
FROM random)) AS id)
...
ALTER TABLE to add a composite primary key
...r 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 ...
NGinx Default public www location?
... have worked with Apache before, so I am aware that the default public web root is typically /var/www/ .
30 Answers
...
Rails 3 execute custom sql query without a model
...
How about this :
@client = TinyTds::Client.new(
:adapter => 'mysql2',
:host => 'host',
:database => 'siteconfig_development',
:username => 'username',
:password => 'password'
sql = "SELECT * FROM users"
result = @client.execute(sql)
results.each d...
Using a .php file to generate a MySQL dump
... done by the command itself.
That external command will :
be a call to mysqldump, with the right parameters,
and redirect the output to a file.
For example :
mysqldump --user=... --password=... --host=... DB_NAME > /path/to/output/file.sql
Which means your PHP code would look like this...
What are the best PHP input sanitizing functions?
...to the server. If you haven't worked with PDO before here's a pretty good MySQL-oriented tutorial.
Some SQL databases have their own specialty extensions in PHP, including SQL Server, PostgreSQL and SQLite 3. Each of those extensions has prepared statement support that operates in the same prepare...
项目管理实践【六】自动同步数据库【Using Visual Studio with Source Cont...
...项目管理实践【五】自动编译和发布网站中，我们讲解了如何使用MSBuild+Robocopy+WebDeployment来自动编译和部署网站，今天，我们来 在上一篇项目管理实践【五】自动编译和发布网站中，我们讲解了如何使用MSBuild+Robocopy+WebDeployment...
Getting “Lock wait timeout exceeded; try restarting transaction” even though I'm not using a transac
I'm running the following MySQL UPDATE statement:
17 Answers
17
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