MySQL Competency (Intermediate Level)

  • 20m
  • 20 questions
The MySQL Competency benchmark will measure your ability to use inner and outer joins to combine data from different relations in MySQL and use the GROUP BY and HAVING operators in SQL to analyze aggregates of data. You will be evaluated on your skills in analyzing normal forms to optimize the structure of relations, using appropriate indices to speed up query execution, and using views to build abstractions for complex and common query operations. A learner who scores high on this benchmark demonstrates that they have the skills to use subqueries and joins, normalize tables, create views and apply indices in MySQL.

Topics covered

  • compute the cross-join of two relations
  • compute the inner join of two relations
  • compute the left outer join of two relations
  • compute the right outer join of two relations
  • create composite indices and drop indices
  • define the natural join operator
  • evaluate the number of tables needed to appropriately store and model data
  • identify and apply the first three normal forms of database design
  • identify and rectify violations of the First Normal Form in MySQL
  • identify violations of the Second Normal Form in MySQL
  • implement a cross product in MySQL
  • implement joins with more than two relations in MySQL
  • implement views in MySQL
  • perform join operations in MySQL
  • rectify violations of the Second Normal Form in MySQL by refactoring table design
  • use the DISTINCT keyword as well as the GROUP BY clause to identify duplicates and cardinality
  • use the HAVING keyword along with the GROUP BY clause to apply filters to aggregates
  • use the SOME, ALL, and ANY keywords to link subqueries to outer queries
  • use views to abstract complex queries in MySQL
  • view indices on an existing table and create new indices on columns