Data
Essential SQL
Query a relational database with the fundamental SQL statements.
This course teaches you to extract and cross-reference data using the SQL language. You handle selection queries, joins and aggregation functions. Running project: you write a set of concrete queries against a sample database.
Objectives
- Understand the relational model
- Write SELECT, WHERE and ORDER BY queries
- Combine tables with joins
- Summarise data with aggregates
- Build queries useful in daily work
Program
Querying a table
- Relational model and tables
- SELECT and column selection
- Filtering with WHERE
- Sorting with ORDER BY
Combining data
- Primary and foreign keys
- Inner joins
- Outer joins
- Aliases and query readability
Aggregating and summarising
- COUNT, SUM, AVG functions
- Grouping with GROUP BY
- Filtering groups with HAVING
- Running project: queries on a database
Prerequisites
No prerequisites.