SELECT Statements
A SELECT statement can consist of the following basic clauses.
- SELECT
- INTO
- FROM
- JOIN
- WHERE
- GROUP BY
- HAVING
- UNION
- ORDER BY
- LIMIT
SELECT Syntax
The following syntax diagram outlines the syntax supported by the Presto adapter:
SELECT {
[ TOP <numeric_literal> | DISTINCT ]
{
*
| {
<expression> [ [ AS ] <column_reference> ]
| { <table_name> | <correlation_name> } .*
} [ , ... ]
}
{
FROM <table_reference> [ [ AS ] <identifier> ]
} [ , ... ]
[ [
INNER | { { LEFT | RIGHT | FULL } [ OUTER ] }
] JOIN <table_reference> [ ON <search_condition> ] [ [ AS ] <identifier> ]
] [ ... ]
[ WHERE <search_condition> ]
[ GROUP BY <column_reference> [ , ... ]
[ HAVING <search_condition> ]
[ UNION [ ALL ] <select_statement> ]
[
ORDER BY
<column_reference> [ ASC | DESC ] [ NULLS FIRST | NULLS LAST ]
]
[
LIMIT <expression>
[
{ OFFSET | , }
<expression>
]
]
} | SCOPE_IDENTITY()
<expression> ::=
| <column_reference>
| @ <parameter>
| ?
| COUNT( * | { [ DISTINCT ] <expression> } )
| { AVG | MAX | MIN | SUM | COUNT } ( <expression> )
| NULLIF ( <expression> , <expression> )
| COALESCE ( <expression> , ... )
| CASE <expression>
WHEN { <expression> | <search_condition> } THEN { <expression> | NULL } [ ... ]
[ ELSE { <expression> | NULL } ]
END
| <literal>
| <sql_function>
<search_condition> ::=
{
<expression> { = | > | < | >= | <= | <> | != | LIKE | NOT LIKE | IS NULL | IS NOT NULL | IN | NOT IN | AND | OR | BETWEEN | CONTAINS | NOT CONTAINS | + | - } [ <expression> ]
} [ { AND | OR } ... ]
Examples
- Return all columns:
SELECT * FROM [Hive].[Default].Customers
- Rename a column:
SELECT "Name" AS MY_Name FROM [Hive].[Default].Customers
- Cast a column's data as a different data type:
SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM [Hive].[Default].Customers
- Search data:
SELECT * FROM [Hive].[Default].Customers WHERE Industry = 'Floppy Disks'
- The Presto APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, LIKE, NOT LIKE, IS NULL, IS NOT NULL, IN, NOT IN, AND, OR, BETWEEN, CONTAINS, NOT CONTAINS, +, -.
SELECT * FROM [Hive].[Default].Customers WHERE Industry = 'Floppy Disks';
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM [Hive].[Default].Customers
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT Name) FROM [Hive].[Default].Customers
- Return the unique items matching the query criteria:
SELECT DISTINCT Name FROM [Hive].[Default].Customers
- Sort a result set in ascending order:
SELECT Id, Name FROM [Hive].[Default].Customers ORDER BY Name ASC
Aggregate Functions
For SELECT examples using aggregate functions, see Aggregate Functions.
JOIN Queries
See JOIN Queries for SELECT query examples using JOINs.
Date Literal Functions
Date Literal Functions contains SELECT examples with date literal functions.
Projection Functions
See Projection Functions for SELECT examples with projection functions.
Predicate Functions
For SELECT examples using predicate functions, see Predicate Functions.