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>
]
]
} | 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
| {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 * FROM DirectoryRoles
- Rename a column:
SELECT [displayName] AS MY_displayName FROM DirectoryRoles
- Cast a column's data as a different data type:
SELECT CAST(passwordValidityPeriodInDays AS VARCHAR) AS Str_passwordValidityPeriodInDays FROM DirectoryRoles
- Search data:
SELECT * FROM DirectoryRoles WHERE Id = 'Jq74mCczmFXk1tC10GBs'
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM DirectoryRoles
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT displayName) FROM DirectoryRoles
- Return the unique items matching the query criteria:
SELECT DISTINCT displayName FROM DirectoryRoles
- Sort a result set in ascending order:
SELECT Id, displayName FROM DirectoryRoles ORDER BY displayName ASC
- Restrict a result set to the specified number of rows:
SELECT Id, displayName FROM DirectoryRoles 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 DirectoryRoles 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 Azure Active Directory.
SELECT * FROM DirectoryRoles WHERE Pseudo = '@Pseudo'
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.