Database

Using the REFERENTIAL_CONSTRAINTS table in MySQL – Foreign Key Awareness

Using FOREIGN KEY‘s in database schema design assist in storing consistent, normalized, and sound data. Oftentimes, many tables wind up with many FOREIGN KEY constraints. However, keeping up with this (potential) maze of relationships doesn’t have to be a nightmare. Want to learn more? Keep reading…

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Column ordering in MySQL using ALTER TABLE – with examples.

MySQL allows table columns to be placed in a specific location among the other present columns. You likely don’t care one iota about column ordering. But, if you do – and your table is already established – you can still have your cake and eat it too by using simple ALTER TABLE commands in conjunction with certain keywords and place those columns in a position to your liking. Continue reading to see example queries…

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SQL CRUD Basics Part 4 – Delete.

In this final part of the SQL CRUD Basics series, we visit the all-mighty and powerful DELETE command. Does that word frighten you? It should, as DELETE will completely remove rows of that oh-so-important data from your database table. Without warning or question, it will be gone. Perhaps your goal is to remove all rows. Great, no problem. However, removing a specific row or set of rows – instead of them all – requires filtering with a WHERE clause predicate, just the same as you would in SELECT and UPDATE statements. Continue reading to see DELETE command examples for better understanding…

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SQL CRUD Basics Part 3 – Update.

Some data may never change. Yet, other data will change. In SQL, you modify existing rows of data with the UPDATE command. UPDATE is a powerful command as it can potentially change multiple rows of data in a single execution – for better or worse. UPDATE is categorized as a DML command which means: Data Manipulation Language. Let’s learn how to use this integral command with examples…

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SQL CRUD Basics Part 2 – Read

In SQL CRUD Basics Part 1 – Create, we learned how to create new rows of data in a database table with the INSERT statement. In this post, we are going to visit the busiest statement in SQL – SELECT. If you want to view or read the stored data in a table, you use SELECT.

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