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 SQL engine of the driver:
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 | NOT LIKE | IN | NOT IN | IS NULL | IS NOT NULL | AND | OR | CONTAINS | BETWEEN } [ <expression> ]
} [ { AND | OR } ... ]
Examples
- Return all columns:
SELECT * FROM Files
- Rename a column:
SELECT [Name] AS MY_Name FROM Files
- Cast a column's data as a different data type:
SELECT CAST(Size AS VARCHAR) AS Str_Size FROM Files
- Search data:
SELECT * FROM Files WHERE Id = '123'
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM Files
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT Name) FROM Files
- Return the unique items matching the query criteria:
SELECT DISTINCT Name FROM Files
- Summarize data:
SELECT Name, MAX(Size) FROM Files GROUP BY Name
See Aggregate Functions for details. - Retrieve data from multiple tables.
SELECT Customers.ContactName, Orders.OrderDate FROM Customers, Orders WHERE Customers.CustomerId=Orders.CustomerId
See JOIN Queries for details. - Sort a result set in ascending order:
SELECT Id, Name FROM Files ORDER BY Name ASC
- Restrict a result set to the specified number of rows:
SELECT Id, Name FROM Files LIMIT 10
- Parameterize a query to pass in inputs at execution time. This enables you to create prepared statements and mitigate SQL injection attacks.
SELECT * FROM Files WHERE Id = @param
Pseudo Columns
Some input-only fields are available in SELECT statements. These fields, called pseudo columns, do not
appear as regular columns in the results, yet may be specified as part of the WHERE clause. You can use pseudo columns to access additional features from Box.
SELECT * FROM Files WHERE Pseudo = '@Pseudo'