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 Xero adapter:
SELECT {
[ TOP <numeric_literal> | DISTINCT ]
{
*
| {
<expression> [ [ AS ] <column_reference> ]
| { <table_name> | <correlation_name> } .*
} [ , ... ]
}
{
FROM <table_reference> [ [ AS ] <identifier> ]
} [ , ... ]
[
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 | AND | OR } [ <expression> ]
} [ { AND | OR } ... ]
Examples
- Return all columns:
SELECT * FROM Contacts
- Rename a column:
SELECT "Name" AS MY_Name FROM Contacts
- Cast a column's data as a different data type:
SELECT CAST(Discount AS VARCHAR) AS Str_Discount FROM Contacts
- Search data:
SELECT * FROM Contacts WHERE ContactStatus = 'ACTIVE'
- The Xero APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, LIKE, AND, OR.
SELECT * FROM Contacts WHERE ContactStatus = 'ACTIVE';
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM Contacts
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT Name) FROM Contacts
- Return the unique items matching the query criteria:
SELECT DISTINCT Name FROM Contacts
- Sort a result set in ascending order:
SELECT Discount, Name FROM Contacts 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.
Window Functions
See Window Functions for SELECT examples containing window functions.
Table-Valued Functions
See Table-Valued Functions for SELECT examples with table-valued functions.