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 SparkSQL adapter:
SELECT {
[ TOP <numeric_literal> | DISTINCT ]
{
*
| {
<expression> [ [ AS ] <column_reference> ]
| { <table_name> | <correlation_name> } .*
} [ , ... ]
}
[ INTO csv:// [ filename= ] <file_path> [ ;delimiter=tab ] ]
{
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 | IN | NOT IN | AND | OR | IS NULL | IS NOT NULL } [ <expression> ]
} [ { AND | OR } ... ]
Examples
- Return all columns:
SELECT * FROM Customers
- Rename a column:
SELECT "CompanyName" AS MY_CompanyName FROM Customers
- Cast a column's data as a different data type:
SELECT CAST(Balance AS VARCHAR) AS Str_Balance FROM Customers
- Search data:
SELECT * FROM Customers WHERE Country = 'US'
- The SparkSQL APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, LIKE, IN, NOT IN, AND, OR, IS NULL, IS NOT NULL.
SELECT * FROM Customers WHERE Country = 'US';
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM Customers
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT CompanyName) FROM Customers
- Return the unique items matching the query criteria:
SELECT DISTINCT CompanyName FROM Customers
- Sort a result set in ascending order:
SELECT City, CompanyName FROM Customers ORDER BY CompanyName 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.