Tuesday, 18 February 2025
How To Create PostgreSQL Foreign Table? PostgreSQL Foreign Data | Best P...
Saturday, 8 February 2025
How To Create Partitions In PostgreSQL || Partitions Explained || Best P...
Friday, 7 February 2025
What Is Inheritance In PostgreSQL? PostgreSQL Inheritance || Best Postgr...
PostgreSQL supports table inheritance, a powerful feature that allows tables to inherit structure and data from other tables. This enables database designers to model complex real-world relationships efficiently.
🔹 Understanding PostgreSQL Inheritance
Inheritance in PostgreSQL allows a child table to automatically acquire the columns of a parent table. This is useful for scenarios where multiple tables share common attributes but also require unique fields.
🔹 Basic Example: Cities and Capitals
We demonstrate how a capitals
table can inherit from a cities
table, making data retrieval more streamlined. Queries on the parent table can include data from child tables, but you can also filter specific tables using the ONLY
keyword.
🔹 Querying Inherited Data
- Retrieve all records (including inherited rows)
- Query only parent table records using
ONLY
- Identify source tables using the
tableoid
system column
🔹 Limitations & Constraints
While CHECK and NOT NULL constraints are inherited, primary keys, unique constraints, and foreign keys are not. This video explores how to work around these limitations effectively.
🔹 Advanced Inheritance Features
- Multiple Inheritance – A table can inherit from multiple parent tables, merging attributes from all.
- Dynamic Inheritance – Modify inheritance relationships on the fly using
ALTER TABLE
. - Dropping Parent Tables – Child tables must be handled carefully before dropping a parent table.
🔹 Real-World Applications
We explore practical use cases where inheritance simplifies schema design, improves query performance, and enhances access control.
📌 Conclusion
PostgreSQL inheritance is a flexible tool for organizing database schemas, but it has limitations regarding constraints, indexing, and insert behavior. Understanding these aspects will help you design efficient and scalable databases.
🚀 Next Topic: Table Partitioning in PostgreSQL – Stay tuned!
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Saturday, 1 February 2025
PostgreSQL Schemas Explained || Schemas Advanced Options In PostgreSQL |...
Tuesday, 28 January 2025
What Is A Schema In PostgreSQL? PostgreSQL Schemas Explained || Best Pos...
Welcome to the Best PostgreSQL Tutorial Series! 🎥 In this video (#22), we explore the concept of schemas in PostgreSQL, a crucial tool for database management.
A schema in PostgreSQL is a logical namespace within a database, allowing you to group related objects such as tables, sequences, indexes, and views. This makes database organization more efficient and prevents naming conflicts in shared databases. Think of schemas as directories in an operating system—but without nesting capabilities.
What You'll Learn in This Video:
📌 Introduction to Schemas:
- What schemas are and how they work in PostgreSQL.
- The hierarchy of database clusters, databases, and schemas.
📌 Benefits of Using Schemas:
- Logical grouping of objects for better manageability.
- Separation of users and applications.
- Avoiding naming conflicts.
📌 Hands-On Examples:
- Creating schemas using
CREATE SCHEMA
. - Adding objects (like tables) to schemas using qualified names.
- Exploring the public schema and its default behavior.
📌 Schema Search Path:
- Learn how PostgreSQL determines where to look for unqualified object names.
- Customize the search path and control object access.
📌 Restricting Access with Schemas:
- How to assign schema ownership to specific users.
By the end of this video, you'll understand how schemas work and be able to organize your PostgreSQL databases like a pro! 🚀
Don’t forget to like 👍, share 🔄, and subscribe 🔔 for more database tutorials.
Wednesday, 22 January 2025
Row Level Security (RLS) Policies In PostgreSQL Explained || Best Postgr...
Friday, 17 January 2025
ACL: Access Control Lists || Privileges In PostgreSQL Explained | Best P...
Tuesday, 7 January 2025
Privileges In PostgreSQL Explained || #GRANT #REVOKE Options || Best Pos...
Friday, 3 January 2025
How To Return Refcursor From PostgreSQL Procedure || PostgreSQL Refcurso...
Unlock the power of refcursor parameters in PostgreSQL with this comprehensive tutorial! In this video, you'll learn how to create and utilize procedures that return refcursors, enabling dynamic result sets from your database.
Key Highlights:
- Writing PostgreSQL procedures with multiple parameters.
- Using the
refcursor
data type for flexible query results. - Step-by-step example demonstrating the
refcursor_cursor
procedure. - Fetching results from a
refcursor
after execution.
This tutorial explains the logic behind the example procedure, which accepts an actor ID as input, calculates the total number of films they are associated with, and dynamically returns film titles using a refcursor
.
Code Explanation:
- The procedure calculates the total number of films for an actor and opens a
refcursor
with the film titles. - Learn how to call this procedure and fetch the results efficiently.
- Handle exceptions effectively to ensure reliable database operations.
Whether you're a beginner or a seasoned database professional, this video provides insights into advanced PostgreSQL concepts with practical examples to elevate your skills!
Make sure to watch the full video, try the code, and share your experience in the comments.
-- How To Return Refcursor From PostgreSQL Procedure
-- Multiple Parameters Involved
create or replace procedure
refcursor_cursor(in_actor_id in integer, lv_ref_cur refcursor, total_films OUT numeric)
language plpgsql
as $$
begin
select
count(*) into total_films
from
film_actor fa,
film f
where
fa.film_id = f.film_id
and fa.actor_id = in_actor_id;
open lv_ref_cur for
select
'Title: ' || f.title as Title
from
film_actor fa, film f
where fa.film_id = f.film_id
and fa.actor_id = in_actor_id;
exception when others then
raise notice 'Something Went Wrong';
end;
$$
call refcursor_cursor(1,'lv_refcursor',2);
fetch all in lv_refcursor;
call refcursor_cursor(1,'lv_refcursor',2);