Name
SELECT
Synopsis
SELECT [STRAIGHT_JOIN] [DISTINCT|ALL]value
[,value2
...] [INTO OUTFILE 'filename
'delimiters
] FROMtable
[,table2
...] [clause
]
Retrieve data from a database. The SELECT
statement is the primary method of reading data from database tables.
If you specify more than one table, MySQL will automatically join the
tables so that you can compare values between the tables. In cases
where MySQL does not perform the join in an efficient manner, you can
specify STRAIGHT_JOIN
to force MySQL to join the
tables in the order you enter them in the query.
If the DISTINCT
keyword is present, only one row of
data will be output for every group of rows that is identical. The
ALL
keyword is the opposite of distinct and
displays all returned data. The default behavior is
ALL
.
The returned values can be any one of the following:
- Aliases
Any complex column name or function can be simplified by creating an alias for it. The value can be referred to by its alias anywhere else in the
SELECT
statement (e.g.,SELECT DATE_FORMAT(date,"%W, %M %d %Y") as nice_date FROM calendar
).- Column names
These can be specified as
column
,table.column
ordatabase.table.column
. The longer forms are necessary only to disambiguate columns with the same name, but can be used at any time (e.g.,SELECT name FROM people; SELECT mydata.people.name FROM people)
.- Functions
MySQL supports a wide range of built-in functions (see later). In addition, user defined functions can be added at any time using the
CREATE FUNCTION ...
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