Write SQL queries to select, delete, insert, and update data in a relational database
Learning/improvement resources: 
Demonstrated by: 

A Skilled SQL programmer should be able to do the following:

  • Write basic SQL queries to select, insert, update, and delete data with WHERE clauses
  • Use JOIN, UNION, and GROUP BY for more complex queries
  • Create and modify tables using queries

An Expert SQL programmer should additionally be able to do the following:

  • Understand the differences between the SQL used in different databases, especially MySQL, PostgreSQL, and SQLite (supported by Drupal core)
  • Program queries using the Drupal Database API (based on PDO)
  • Programmatically create tables using the Drupal Schema API
Related skills: 
Database administration
PHP coding/programming

Roles and Tasks that may use this skill

Create a merge request for an issue (Contributor task)
Add or update a "merge request" (software fix) on an issue
Duration: 1 hour
Drupal core subsystem maintainer (Contributor role)
Oversee the development of a module, theme, or other subset of Drupal core
Duration: ongoing