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“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
... but the values you insert don't map to a partition.
If you use REPLACE, MySQL actually does a DELETE followed by an INSERT internally, which has some unexpected side effects:
A new auto-increment ID is allocated.
Dependent rows with foreign keys may be deleted (if you use cascading foreign ke...
How to organize a node app that uses sequelize?
...getting data completely. And reasons are - imagine that you don't just use MySQL (in my case, I use MySQL and MongoDB side by side), but you can get your data from any data provider and any transport method, e.g. SQL, no-SQL, filesystem, external API, FTP, SSH etc. If you tried to do all of it in th...
Cast int to varchar
... @JonathanSayce I'm not overly familiar with the ins & outs of MySQL and it might not use something arbitrary, but I wouldn't rely on the MySQL engine to be that smart (no offense to MySQL). In order to be sure you get the proper length, I would always explicitly provide one.
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Installing specific package versions with pip
I'm trying to install version 1.2.2 of the MySQL_python adaptor, using a fresh virtualenv created with the --no-site-packages option. The current version shown in PyPi is 1.2.3 . Is there a way to install the older version? I found an article stating that this should do it:
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When to use Hadoop, HBase, Hive and Pig?
...ru some SQL like language
To replace daily aggregation data generated thru MySQL with Hive
Build Custom reports thru queries in Hive
Architecture Options
I benchmarked the following options:
Hive+HDFS
Hive+HBase - queries were too slow so I dumped this option
Design
Daily log Files were tr...
Is the primary key automatically indexed in MySQL?
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According to http://dev.mysql.com/doc/refman/5.0/en/constraint-primary-key.html it would appear that this is would be implicit
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Convert from MySQL datetime to another format with PHP
I have a datetime column in MySQL.
18 Answers
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MySQL select one column DISTINCT, with corresponding other columns
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@Full Decent you can't, according to MySQL documentation: "The server is free to choose any value from each group, so unless they are the same, the values chosen are indeterminate.". In practice I've successfully used this kind of queries with ORDER BY clause, ...
MySQL: Large VARCHAR vs. TEXT?
I've got a messages table in MySQL which records messages between users. Apart from the typical ids and message types (all integer types) I need to save the actual message text as either VARCHAR or TEXT. I'm setting a front-end limit of 3000 characters which means the messages would never be inserte...
python-pandas and databases like mysql
...ing a DBI compatible library. We can look at two short examples using the MySQLdb and cx_Oracle libraries to connect to Oracle and MySQL and query their data dictionaries. Here is the example for cx_Oracle:
import pandas as pd
import cx_Oracle
ora_conn = cx_Oracle.connect('your_connection_string'...