I think the main reason is for data integrity. If you have a relationship between two tables invoice and invoice_item. You won’t be able to add an invoice item that does not related to an invoice. This is what you want! It’s called referential integrity. It can get pretty messy in your database if you don’t have … Read more
Use sp_rename See: SQL SERVER – How to Rename a Column Name or Table Name Documentation: sp_rename (Transact-SQL) For your case it would be: Remember to use single quotes to enclose your values.
You can’t concatenate an int to a string. Instead of: You need: To help illustrate what’s happening here. Let’s say @RowTo = 5. In order to build that into a string (even if ultimately it will be a number), I need to convert it. But as you can see, the number is still treated as … Read more
Remove the course_enrollment_settings.base_price immediately after CASE: CASE has two different forms, as detailed in the manual. Here, you want the second form since you’re using search conditions.
I have been looking at this code for the past two days now and I can not seem to get it to work. It keeps giving me ORA-00907: missing right parenthesis. I know that this is a topic that comes up a lot but for some reason none of the examples I have seen has … Read more
You must put all columns of the SELECT in the GROUP BY or use functions on them which compress the results to a single value (like MIN, MAX or SUM). A simple example to understand why this happens: Imagine you have a database like this: and you run SELECT * FROM table GROUP BY foo. … Read more
XAMPP only offers MySQL (Database Server) & Apache (Webserver) in one setup and you can manage them with the xampp starter. After the successful installation navigate to your xampp folder and execute the xampp-control.exe Press the start Button at the mysql row. Now you’ve successfully started mysql. Now there are 2 different ways to administrate … Read more
You can’t concatenate an int to a string. Instead of: You need: To help illustrate what’s happening here. Let’s say @RowTo = 5. In order to build that into a string (even if ultimately it will be a number), I need to convert it. But as you can see, the number is still treated as … Read more
Syntax strictly depends on which SQL DBMS you’re using. Here are some ways to do it in ANSI/ISO (aka should work on any SQL DBMS), MySQL, SQL Server, and Oracle. Be advised that my suggested ANSI/ISO method will typically be much slower than the other two methods, but if you’re using a SQL DBMS other … Read more
SQLFiddle will let you test out your queries, while it doesn’t explicitly correct syntax etc. per se it does let you play around with the script and will definitely let you know if things are working or not.