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SQL WITH clause example [duplicate]
...ngle sub-query alias.
WITH <alias_name> AS (sql_subquery_statement)
SELECT column_list FROM <alias_name>[,table_name]
[WHERE <join_condition>]
When using multiple sub-query aliases, the syntax is as follows.
WITH <alias_name_A> AS (sql_subquery_statement),
<alias_name_...
Joining three tables using MySQL
...
Simply use:
select s.name "Student", c.name "Course"
from student s, bridge b, course c
where b.sid = s.sid and b.cid = c.cid
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How to check if field is null or empty in MySQL?
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Either use
SELECT IF(field1 IS NULL or field1 = '', 'empty', field1) as field1
from tablename
or
SELECT case when field1 IS NULL or field1 = ''
then 'empty'
else field1
end as field1
from tablename
...
SQL query to group by day
...dateadd(DAY,0, datediff(day,0, created)) return '2009-11-02 00:00:00.000'
select sum(amount) as total, dateadd(DAY,0, datediff(day,0, created)) as created
from sales
group by dateadd(DAY,0, datediff(day,0, created))
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How to recover MySQL database from .myd, .myi, .frm files
...ql\data\foldername\.mydfiles
Then visit localhost/phpmyadmin in a browser. Select the database you have just pasted into the mysql\data folder, and click on Export in the navigation bar. Chooses the export it as a .sql file. It will then pop up asking where the save the file
And that is it! You (s...
Run php script as daemon process
... service:
[Unit]
Description=My PHP Daemon Service
#May your script needs MySQL or other services to run, eg. MySQL Memcached
Requires=mysqld.service memcached.service
After=mysqld.service memcached.service
[Service]
User=root
Type=simple
TimeoutSec=0
PIDFile=/var/run/myphpdaemon.pid
ExecStart=/u...
How to drop unique in MySQL?
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DROP INDEX column_name ON table_name
Select the database and query form the sql tab.This removes the index of the particular column. It worked for me in PHP MyADMIN
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What is the leading LINQ for JavaScript library? [closed]
... different names (in fact, they have more traditional names than in Linq). Select becomes map, Where becomes filter, First and FirstOrDefault become [0].
Almost no library I know of (including I think the ones you linked to) bother to make the implementation lazy as in .NET Linq, they just evaluate...
What are POD types in C++?
... PODs,
enums are PODs
a const or volatile POD is a POD.
a class, struct or union of PODs is a POD provided that all non-static data members are public, and it has no base class and no constructors, destructors, or virtual methods. Static members don't stop something being a POD under this rule. This...
Which MySQL datatype to use for an IP address? [duplicate]
...nvert them:
INSERT INTO `table` (`ipv4`) VALUES (INET_ATON("127.0.0.1"));
SELECT INET_NTOA(`ipv4`) FROM `table`;
For IPv6 addresses you could use a BINARY instead:
`ipv6` BINARY(16)
And use PHP’s inet_pton and inet_ntop for conversion:
'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_es...