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> } .*
} [ , ... ]
}
{
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>
]
]
}
<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
| {RANK() | DENSE_RANK()} OVER ([PARTITION BY <column_reference>] {ORDER BY <column_reference>})
| <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 Country, Education FROM [adventureworks].[Model].Customer
- Rename a column:
SELECT [Education] AS MY_Education FROM [adventureworks].[Model].Customer
- Cast a column's data as a different data type:
SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM [adventureworks].[Model].Customer
- Search data:
SELECT Country, Education FROM [adventureworks].[Model].Customer WHERE Country = 'Australia'
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM [adventureworks].[Model].Customer
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT Education) FROM [adventureworks].[Model].Customer
- Return the unique items matching the query criteria:
SELECT DISTINCT Education FROM [adventureworks].[Model].Customer
- Sort a result set in ascending order:
SELECT Country, Education FROM [adventureworks].[Model].Customer ORDER BY Education ASC
- Restrict a result set to the specified number of rows:
SELECT Country, Education FROM [adventureworks].[Model].Customer 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 Country, Education FROM [adventureworks].[Model].Customer WHERE Country = @param
Aggregate Functions
For SELECT examples using aggregate functions, see Aggregate Functions.
JOIN Queries
See JOIN Queries for SELECT query examples using JOINs.
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.