Animated SQl for Beginners

Create and delete databases in Postgres by running create database demo or employee, explore servers, schemas, and tables, and use create and drop statements in queries.

Learn to create a customer table with customer_id and first_name, define data types like integer and vaja, perform insert operations, delete records, and drop the table.

Learn to use sql select statement to fetch records from the student table, selecting one or more columns, with select * to fetch columns, and how column order shapes output.

Learn to format customer names using SQL string functions—upper and lower for case, concat to join names, and substring for extracting parts with 1-based indexing.

Learn to perform calculations in sql using arithmetic operators such as addition, subtraction, multiplication, division, and modulo. See how to apply them to column values in select statements.

Filter records from a table using select statements and the from clause to show customers named Emma. Apply where conditions to return customers with balance greater than 30.

Use the between operator to select customers with a balance between 25 and 55 from the customer table, with endpoints included. The example demonstrates applying between to names and dates.

Use the smaller than operator to filter customers with balances under 35, via a query like select * from customer where balance is smaller than 35, and other comparison operators.

Learn to use the in operator to filter customer records by country, selecting USA or Italy, by writing and executing a sql query.

Update statements modify existing records in a table by using update and set to change a customer's balance to 1000 for name Emma, then verify with a select.

Learn to delete records in sql by using delete from a table with a where clause to target specific rows, such as name Emma or balance less than 25.

Explore database design concepts through YouTube examples, illustrating one-to-one, one-to-many, and many-to-many relationships among videos, users, and descriptions.

Declare the video column as a primary key to prevent nulls and duplicates in the YouTube table, insert records, and observe duplicate key violations.

Establish a one-to-many relation by adding a video_id foreign key in the YouTube table that references the videos table and use serial to auto-increment IDs, ensuring referential integrity.

Learn to select records from multiple tables using joins, combine customer and item data, qualify ambiguous column names with table names or aliases, and use table aliases to simplify queries.

Learn to select common records from two tables using an inner join on matching ids between the customer and order tables.

Master left outer join concepts by seeing how it keeps all records from the left table and shows matching right table rows, with non-matches as nulls.

Learn to use a right join to return all records from the right table with matching rows from the left, showing nulls for non-matches and mirroring inner join results.

Learn to select all records from both the customer and orders tables using a full outer join, including unmatched rows, and write the sql to perform the join.

Explore how table order across joins affects results. Inner joins stay the same, while left and right joins change outputs; full joins remain unaffected.

Apply the inner join on the customer and orders tables, then filter the output to show only records where the item equals mobile.

Learn how to group records with sql using group by, generate unique items, and apply aggregates within select statements while understanding errors for non-grouped columns.

Explore aggregate functions in SQL with group by, including count, sum, avg, max, and min per group. Learn how group by shapes results and why aggregates require grouped columns.

Learn to filter groups using the having clause after group by item, calculating the total items sold with sum and keeping groups where the total sold exceeds four.

Learn how the order by clause sorts records in the customer table by total, in ascending or descending order, and how to sort by multiple columns.

Learn to limit records returned by a select statement by ordering customers by amount descending and applying limit and offset to fetch the top buyers.

Learn to fetch USA customers and USA suppliers, then combine their records with union to produce a list of unique entries; union removes duplicates, unlike union all.

Learn how to use sql set operators intersect, union, union all, and except to combine and compare query results, including finding common rows and differences between tables.

Demonstrate subqueries in SQL by listing customer names and IDs with balances greater than the India max balance, using inner and outer queries.

Learn how a correlated subquery identifies, for each country, the customer with the max balance by iterating an outer query and referencing inner results.

Explore how the distinct keyword returns unique records from a column, using paint colors and customer names as examples, and how count and multi-column usage affect results.