Data Manipulation Language
Completion requirements
Read this chapter and take notes on the purpose and use of the clause SELECT and how the INSERT and DELETE statements are used to make changes to data. Also, note how functions are used in these statements.
Joining Tables
Inner join
An inner join connects two tables on a column with the same data type. Only the rows where the column values match are returned; unmatched rows are discarded.
Example #1
SELECT jobs.job_id, job_desc
FROM jobs
INNER JOIN Employees ON employee.job_id = jobs.job_id
WHERE jobs.job_id < 7
Example #2
SELECT authors.au_fname, authors.au_lname, books.royalty, title
FROM authorsINNER JOIN titleauthor ON authors.au_id=titleauthor.au_id
INNER JOIN books ON titleauthor.title_id=books.title_id
GROUP BY authors.au_lname, authors.au_fname, title, title.royalty
ORDER BY authors.au_lname