MySQL in a Nutshell, 2nd Edition

Name

SELECT

Synopsis

SELECT [flags] {*|column|expression}[, ...]
  FROM table[, ...] 
  [WHERE condition]
  [GROUP BY {column|expression|position}[ASC|DESC], ...
     [WITH ROLLUP]]
  [HAVING condition]
  [ORDER BY {column|expression|position}[ASC|DESC] , ...]
  [LIMIT {[offset,] count|count OFFSET offset}]
  [PROCEDURE procedure(arguments)]
  options

Use this statement to retrieve and display data from tables within a database. It has many clauses and options, but for simple data retrieval many of them can be omitted. The basic syntax for the statement is shown. After the SELECT keyword, some keywords to control the whole operation may be given. Next comes an asterisk to retrieve all columns, a list of columns to retrieve, or expressions returning values to display, separated by commas.

Data can be retrieved from one or more tables, given in a comma-separated list. If multiple tables are specified, other clauses must define how the tables are joined. The remaining clauses may be called on to refine the data to be retrieved, to order it, and so forth. These various keywords, options, and clauses are detailed in subsections of this statement explanation. To start, here is a simple example of how you can use the SELECT statement:

SELECT name_first, name_last, telephone_home,
DATEDIFF(now( ), last_review)
AS 'Days Since Last Review'
FROM employees;

In this example, three columns and the results of an expression based on a fourth column are to be displayed. The first and last name of each employee, each employee’s ...