Czechitas Digital Academy: DATA

Codes from SQL lessons which I participated in from September to December 2023.

Lesson content:

1. LESSON No. 1:

   select, from, where, group by + having, order by, data types

   • homework

2. LESSON No. 2:

   cast vs ::, where (conditions - >, <, =, ==, in), agregation, group by

   • homework

3. LESSON No. 3

   string functions (split, lenght, replace, substring, left, right, upper, charindex, possition), select distinct, math functions (haversine, round, floor, ceil, trunc), date functions (to_date, date_from_parts, dateadd, dateiff, extract), ifnull, case when, like, ilike,

   • homework

4. LESSON No. 4:

   joins (inner, left, right, full, cross),

   • homework

5. LESSON No. 5:

   subselect in select, subselect in condition, subselect in from

6. LESSON No. 6:

   repetition of joins, temporary table, CTE, subselect

7. LESSON No. 7:

   repetition of temporary tables, CTEs, subselects, union, union all, window functions aggregation(count() over (), sum() over (), max() over (), min() over (), avg() over ()) partititon by qualify row_number(), rank() window function + group by

   • homework

8. LESSON No. 8:

   uniform, generator, cross join, sequence,

9. OPTIONAL HOMEWORK:

   a) creating the first temporary table with titles * and ratings averageratings and numvotes + 2. converting titletype to titletype_new b) connectiong all tables into one 'netflix_imdb' c) how many duplicates are in the result?

10. REPEATING LESSON: