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 component:
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
| {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 [DemoDB].[PUBLIC].Products
- Rename a column:
SELECT [ProductName] AS MY_ProductName FROM [DemoDB].[PUBLIC].Products
- Cast a column's data as a different data type:
SELECT CAST(Price AS VARCHAR) AS Str_Price FROM [DemoDB].[PUBLIC].Products
- Search data:
SELECT * FROM [DemoDB].[PUBLIC].Products WHERE ProductName = 'Konbu'
- Return the number of items matching the query criteria:
SELECT COUNT(*) AS MyCount FROM [DemoDB].[PUBLIC].Products
- Return the number of unique items matching the query criteria:
SELECT COUNT(DISTINCT ProductName) FROM [DemoDB].[PUBLIC].Products
- Return the unique items matching the query criteria:
SELECT DISTINCT ProductName FROM [DemoDB].[PUBLIC].Products
- Sort a result set in ascending order:
SELECT Id, ProductName FROM [DemoDB].[PUBLIC].Products ORDER BY ProductName ASC
- Restrict a result set to the specified number of rows:
SELECT Id, ProductName FROM [DemoDB].[PUBLIC].Products 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 [DemoDB].[PUBLIC].Products WHERE ProductName = @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 Snowflake.
SELECT * FROM [DemoDB].[PUBLIC].Products WHERE MyPseudocolumn = 'MyValue'
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.
Projection Functions
See Projection Functions for SELECT examples with projection functions.
Predicate Functions
For SELECT examples using predicate functions, see Predicate Functions.