SELECT

Syntax

SELECT
    [ALL | DISTINCT | DISTINCTROW]
    [HIGH_PRIORITY]
    [STRAIGHT_JOIN]
    [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
    [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]
    select_expr [, select_expr ...]
    [ FROM table_references
      [WHERE where_condition]
      [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]]
      [HAVING where_condition]
      [ORDER BY {col_name | expr | position} [ASC | DESC], ...]
      [LIMIT {[offset,] row_count | row_count OFFSET offset}]
      [PROCEDURE procedure_name(argument_list)]
      [ INTO OUTFILE 'file_name' [CHARACTER SET charset_name] export_options
      | INTO DUMPFILE 'file_name'
      | INTO var_name [, var_name] ]
      [FOR UPDATE | LOCK IN SHARE MODE] ]

Description

SELECT is used to retrieve rows selected from one or more tables, and can include UNION statements and subqueries. See UNION, and http://dev.mysql.com/doc/refman/5.1/en/subqueries.html.

The most commonly used clauses of SELECT statements are these:

• Each select_expr expression indicates a column or data that you want to retrieve. You must have at least one select expression. See Select Expressions below.
• The FROM clause indicates the table or tables from which to retrieve rows. Use either a single table name or a JOIN expression. See JOIN for details.
• The WHERE clause, if given, indicates the condition or conditions that rows must satisfy to be selected. where_condition is an expression that evaluates to true for each row to be selected. The statement selects all rows if there is no WHERE clause.
  • In the WHERE clause, you can use any of the functions and operators that MySQL supports, except for aggregate (summary) functions. See http://dev.mysql.com/doc/refman/5.1/en/functions.html

SELECT can also be used to retrieve rows computed without reference to any table.

Select Expressions

A SELECT statement must contain one or more select expressions, separated by commas. Each select expression can be one of the following:

• The name of a column.
• Any expression using functions and operators.
• * to select all columns from all tables in the FROM clause.
• tbl_name.* to select all columns from just the table tbl_name.

When specifying a column, you can either use just the column name or qualify the column name with the name of the table using tbl_name.col_name. The qualified form is useful if you are joining multiple tables in the FROM clause. If you do not qualify the column names when selecting from multiple tables, MariaDB will try to find the column in each table. It is an error if that column name exists in multiple tables.

You can quote column names using backticks. If you are qualifying column names with table names, quote each part separately as `tbl_name`.`col_name`.

If you use any grouping functions in any of the select expressions, all rows in your results will be implicitly grouped, as if you had used GROUP BY NULL.