The article presents a detailed tutorial on MySQL JOINs. In it, you will learn about different types of JOINS that are supported in MySQL, their syntax, and how to use them. Introduction to MySQL JOINsDifferent types of JOINs in MySQL1. MySQL INNER JOIN clause2. MySQL OUTER JOINs2.1 MySQL LEFT JOIN clause2.2 MySQL RIGHT JOIN clause3. […]
JOINs confuse a lot of those new to Structured Query Language (SQL). If you read the various web forums popularly used to ask questions then you know that using JOINs is pretty scary for a lot of folks. The sheer number of the 'how do I use JOIN to link two tables together?' questions is staggering. Not just because the JOIN itself is often obfuscated with relational algebra, Venn Diagrams, and the syntactical oddities of SQL -- and that is when you do find an online resource that tries to help. Plus adding to the frustration on top of all that are that the various options for using JSON can be downright perplexing.
Let us start with an example of customers and their orders. There is one table named customer for the information pertaining to the customer. There is another table with order information named orders holding the details of any orders from those folks in the customer table. …[Read more]
3 ways your MySQL migration project can shake you up
Once a development or operations team gets over the hurdle of open-source, and start to feel comfortable with the way software works outside of the enterprise world, they will likely start to settle in and feel comfortable. Best not to get too cushy though for there are more surprises hiding around the corner. Here are a few of the biggest ones.
1. Replication Is Not Perfect
Yes, you've installed MySQL, setup a slave, and got it replicating properly. You check the slave and it's 0 seconds behind the master. What's more you monitor the error log file, and have a check in place to alert you if something happens there. Job completed, good job!
Not so fast. Unfortunately this is not the end of the story. Many MySQL replication slaves are not consistent with their masters, but they drift apart silently. …[Read more]