MySQL Multiple Joins in one query?

You can simply add another join like this: However be aware that, because it is an INNER JOIN, if you have a message without an image, the entire row will be skipped. If this is a possibility, you may want to do a LEFT OUTER JOIN which will return all your dashboard messages and an image_filename only if … Read more

MySQL “WITH” clause

I’m trying to use MySQL to create a view with the “WITH” clause But it doesn’t seem like MySQL supports this. I thought this was pretty standard and I’m sure Oracle supports this. Is there anyway to force MySQL to use the “WITH” clause? I’ve tried it with the MyISAM and innoDB engine. Both of … Read more

Difference between one-to-many and many-to-one relationship

Yes, it a vice versa. It depends on which side of the relationship the entity is present on. For example, if one department can employ for several employees then, department to employee is a one to many relationship (1 department employs many employees), while employee to department relationship is many to one (many employees work … Read more

What is the meaning of the prefix N in T-SQL statements and when should I use it?

It’s declaring the string as nvarchar data type, rather than varchar You may have seen Transact-SQL code that passes strings around using an N prefix. This denotes that the subsequent string is in Unicode (the N actually stands for National language character set). Which means that you are passing an NCHAR, NVARCHAR or NTEXT value, as opposed to … Read more