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SQL - find records from one table which don't exist in another
...shortest statement, and may be quickest if your phone book is very short:
SELECT *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)
alternatively (thanks to Alterlife)
SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phon...
Difference between “read commited” and “repeatable read”
...nd consider you have a simple task like the following:
BEGIN TRANSACTION;
SELECT * FROM T;
WAITFOR DELAY '00:01:00'
SELECT * FROM T;
COMMIT;
That is a simple task that issue two reads from table T, with a delay of 1 minute between them.
under READ COMMITTED, the second SELECT may return any da...
IntelliJ does not show project folders
...next button which takes you to the Content root. Find your root folder and select it
Click the "ok" button
Ignore any warning that says the name is already in use
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How to make rpm auto install dependencies
...
thanks, I was struggling to install mysql-workbench with rpm -ivh. eventually ended up with this post. DNF did the trick.
– BlueBird
Jul 13 '16 at 13:10
...
Django connection to PostgreSQL: “Peer authentication failed”
...I am receiving when I try to get to my Django admin site. I had been using MySQL database no problem. I am new to PostgreSQL, but decided to switch because the host I ultimately plan to use for this project does not have MySQL.
...
What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in
...lder ("java" under src/main/java if it is a Maven project for example) and select Mark Directory As > Sources Root (see screenshot below).
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How to use JNDI DataSource provided by Tomcat in Spring?
..."7200000"
testOnBorrow="true"
validationQuery="select 1"
/>
</GlobalNamingResources>
And reference the JNDI resource from Tomcat's web context.xml like this:
<ResourceLink name="jdbc/DatabaseName"
global="jdbc/DatabaseName"
type="javax...
PHP Warning: POST Content-Length of 8978294 bytes exceeds the limit of 8388608 bytes in Unknown on l
...oad-max-filesize (change 2M to 2000M).
3. Now stop the Apache server and MySQL.
4. Now restart Apache server and MySQL.
It worked fine after that.
Enjoy ur working now :)
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Unpivot with column name
...hould be able to use the following which includes the subject in the final select list:
select u.name, u.subject, u.marks
from student s
unpivot
(
marks
for subject in (Maths, Science, English)
) u;
See SQL Fiddle with demo
...
mysql command for showing current configuration variables
...ent global setting for the innodb_log_buffer_size in bytes and megabytes:
SELECT
variable_name,
variable_value AS innodb_log_buffer_size_bytes,
ROUND(variable_value / (1024*1024)) AS innodb_log_buffer_size_mb
FROM information_schema.global_variables
WHERE variable_name LIKE 'innodb_log_buffe...