Joining More Than Two Tables
How to Join More than Two Tables
- To include more tables in the query, you simply add more additional JOIN clauses
1 USE world;
2 SELECT ci.name AS "City Name",
3 co.name AS "Country Name",
4 cl.language AS "Country Language"
5 FROM city ci
6 JOIN country co
7 ON ci.CountryCode = co.Code
8 JOIN country language cl
9 ON cl.CountryCode = ci.CountryCode;
JOIN countrylanguage cl.
- The “cl” is the alias for countrylanguage.
- You can refer to tables already specified in a previous join.
ON cl.CountryCode = ci.CountryCode;
- The common column between the two tables being joined is the CountryCode column from the countrylanguage table and the CountryCode column from the city table.
- The “cl” alias previously defined for countrylanguage is used to specify the CountryCode column.