List of lectures for the course SQL, 6 quest level on JavaRush

Working with Strings: LENGTH(), SUBSTRING(), TRIM(), POSITION(), REPLACE(), INITCAP()
SQL SELF
6 level,0 lecture
Overview of the main PostgreSQL string functions: how to extract, modify, search, and format text data using LENGTH, SUBSTRING, TRIM, POSITION, REPLACE, and INITCAP.
Open
Getting Unique Values with DISTINCT
SQL SELF
6 level,1 lecture
Learn how to use the DISTINCT operator in SQL to grab only unique values from tables, get rid of duplicates, and use this tool the right way for data analysis.
Open
Sorting by Multiple Columns: Sort Order and Priorities
SQL SELF
6 level,2 lecture
Learn how to sort data in SQL by multiple columns with different priorities, control the sort direction, and manage where NULL values go for a more structured output.
Open
Examples of Formatting and Sorting Data in Real-World Tasks
SQL SELF
6 level,3 lecture
In this lecture, you'll learn how to format, sort, and clean up data using SQL — this will help you create readable reports, remove duplicates, and prep data for analysis and export. We'll check out practical examples with real tables and SQL queries.
Open
Typical Mistakes When Sorting and Formatting Data
SQL SELF
6 level,4 lecture
Let's break down the most common mistakes when sorting and formatting data in SQL: mixed types, column order, sort directions, quirks with DISTINCT, CAST, CONCAT, and tips on how to avoid them.
Open