List of lectures for the course SQL, 12 quest level on JavaRush

Working with NULL values when joining data
SQL SELF
12 level,0 lecture
Learn how NULL values show up and are handled when joining tables in SQL, how they're different from zero and empty string, and how to deal with them using COALESCE, CASE, filtering, and different types of joins.
Open
Multiple JOINs in One Query
SQL SELF
12 level,1 lecture
Learn how to combine several tables using multiple JOINs in SQL to get complex reports from related data. Examples, optimization tips, and practical scenarios for working with big databases.
Open
Extra conditions in JOIN: ON ... AND ...
SQL SELF
12 level,2 lecture
Learn how to use extra conditions in SQL JOIN with ON ... AND ... for more precise and efficient table joining. Examples, explanations, best practices, and a breakdown of how it’s different from filtering in WHERE.
Open
Self-joining Data with SELF JOIN
SQL SELF
12 level,3 lecture
Learn how to use SELF JOIN to join a table to itself in SQL. We'll check out examples for hierarchies, finding similar records, and common mistakes when working with SELF JOIN.
Open
Common Mistakes When Using JOIN
SQL SELF
12 level,4 lecture
Check out the most common mistakes when working with SQL JOIN: from Cartesian products to missing rows and duplicate data. Learn how to avoid them and write solid queries!
Open