requêtes sql

Introduction to SQL queries

Formation initiation aux requêtes SQL

Compliance to the business - Methods / Technical handling

Goals : This training will teach trainees to:

  • Understand the principle and content of a relational database
  • Create queries to extract data according to different criteria
  • Perform queries with joins, to retrieve information from multiple tables
  • Use simple calculations and data aggregations
  • Combine the results of several queries

Profile targeted

Suitable for all




1. Introduction to databases

  • What is a database?
  • How to manage and exploit these data
  • Reading a relational model.
  • Composition of a table. Notion of columns and types.
  • Primary key and uniqueness.
  • Notion of referential integrity.
  • Tool to query a database.

2. Extract data from a table

  • Extraction query
  • The values to return.
  • The WHERE clause to filter the data.
  • The absence of a value
  • Return rows without duplicates restriction operators (BETWEEN, IN, LIKE...).

3. Query data from several tables

  • Principle of joins: restore information from several tables.
  • Internal join and external join.
  • The "natural" join and its difficulties.
  • Set operators (UNION, INTERSECT...).
  • Introduction to views: principle and interest

4. Scheduling and statistics

  • Find aggregated values (MIN, MAX, AVG, SUM...).
  • Compute relative aggregates with GROUP BY. - Filter aggregated values with HAVING

5. Present / sort data

  • Present column data with aliases.
  • Convert from one type to another.
  • Make choices using the CASE operator.
  • Sort data with ORDER BY. Operations on strings, on dates

6. Subqueries

  • What is a subquery?
  • The different types of results.
  • List subqueries and IN, ANY/SOME and ALL operators

Teaching methods

  • Theory
  • Practical training
  • Feedback

Terms of evaluation

  • Practical work