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 xBase adapter:
SELECT {
[ TOP <numeric_literal> ]
{
*
| {
<expression> [ [ AS ] <column_reference> ]
| { <table_name> | <correlation_name> } .*
} [ , ... ]
}
[ INTO csv:// [ filename= ] <file_path> [ ;delimiter=tab ] ]
{
FROM <table_reference> [ [ AS ] <identifier> ]
}
[ WHERE <search_condition> ]
[ GROUP BY <column_reference> [ , ... ]
[ HAVING <search_condition> ]
[
ORDER BY
<column_reference> [ ASC | DESC ] [ NULLS FIRST | NULLS LAST ]
]
[
LIMIT <expression>
]
}
<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 } [ <expression> ]
} [ { AND | OR } ... ]
Examples
- Return all columns:
SELECT * FROM Orders
- Rename a column:
SELECT "ShipCity" AS MY_ShipCity FROM Orders
- Cast a column's data as a different data type:
SELECT CAST(Freight AS VARCHAR) AS Str_Freight FROM Orders
- Search data:
SELECT * FROM Orders WHERE ShipCountry = 'USA'
- The xBase APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, LIKE, NOT LIKE, IN, NOT IN, IS NULL, IS NOT NULL, AND, OR, CONTAINS.
SELECT * FROM Orders WHERE ShipCountry = 'USA';
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM Orders
- Summarize data:
SELECT ShipCity, MAX(Freight) FROM Orders GROUP BY ShipCity
See Aggregate Functions for details. - Sort a result set in ascending order:
SELECT ShipName, ShipCity FROM Orders ORDER BY ShipCity ASC