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 Dataset_Opportunity
- Rename a column:
SELECT [CloseDate] AS MY_CloseDate FROM Dataset_Opportunity
- Cast a column's data as a different data type:
SELECT CAST(Size AS VARCHAR) AS Str_Size FROM Dataset_Opportunity
- Search data:
SELECT * FROM Dataset_Opportunity WHERE StageName = 'Closed Won'
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM Dataset_Opportunity
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT CloseDate) FROM Dataset_Opportunity
- Return the unique items matching the query criteria:
SELECT DISTINCT CloseDate FROM Dataset_Opportunity
- Summarize data:
SELECT CloseDate, MAX(Size) FROM Dataset_Opportunity GROUP BY CloseDate
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 Name, CloseDate FROM Dataset_Opportunity ORDER BY CloseDate ASC
- Restrict a result set to the specified number of rows:
SELECT Name, CloseDate FROM Dataset_Opportunity 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 Dataset_Opportunity WHERE StageName = @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 Tableau CRM.
SELECT * FROM Dataset_Opportunity WHERE Pseudo = '@Pseudo'