Update postgresqltutorial broken links (#489)

content/04-postgresql/11-date-types.mdx

@@ -126,7 +126,7 @@ Depending on the requirements of a system, you may need a date formatted in a sp
 
 ### Get the interval between two dates
 
-PostgreSQL allows you to get the [interval](https://www.postgresqltutorial.com/postgresql-interval/) between two dates using the `-` operator. Using this operator allows you to calculate things like the tenure of an employee or time since the publishing of a book.
+PostgreSQL allows you to get the [interval](https://www.postgresqltutorial.com/postgresql-tutorial/postgresql-interval/) between two dates using the `-` operator. Using this operator allows you to calculate things like the tenure of an employee or time since the publishing of a book.
 
 In our example we want to find how many days it's been since Joyce's <u>Ulysses</u> was published by subtracting the current date from the `published_date`:
 

content/04-postgresql/12-inserting-and-modifying-data/01-inserting-and-deleting-data.mdx

@@ -367,7 +367,7 @@ WHERE EXISTS ( subquery );
 
 <details><summary>How do I delete duplicate rows in PostgreSQL?</summary>
 
-There are [several methods for deleting duplicate rows](https://www.postgresqltutorial.com/how-to-delete-duplicate-rows-in-postgresql/) in PostgreSQL. You can use a `DELETE USING` statement to check if two different rows have the same value and then delete the duplicate.
+There are [several methods for deleting duplicate rows](https://www.postgresqltutorial.com/postgresql-tutorial/how-to-delete-duplicate-rows-in-postgresql/) in PostgreSQL. You can use a `DELETE USING` statement to check if two different rows have the same value and then delete the duplicate.
 
 In addition, you can use a subquery to delete duplicates or by using an immediate table with the listed steps: