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

1. Return all columns:
   

   SELECT * FROM Customer

2. Rename a column:
   

   SELECT [TotalDue] AS MY_TotalDue FROM Customer

3. Cast a column's data as a different data type:
   

   SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM Customer

4. Search data:
   

   SELECT * FROM Customer WHERE CustomerId = '12345'

5. The Couchbase APIs support the following operators in the WHERE clause: =, !=, <, <=, >, >=, IS NULL, LIKE, AND, OR, NOT, IN.
   

   SELECT * FROM Customer WHERE CustomerId = '12345';

6. Return the number of items matching the query criteria:
   

   SELECT COUNT(*) AS MyCount FROM Customer 

7. Return the number of unique items matching the query criteria:
   

   SELECT COUNT(DISTINCT TotalDue) FROM Customer 

8. Return the unique items matching the query criteria:
   

   SELECT DISTINCT TotalDue FROM Customer 

9. Summarize data:
   

   SELECT TotalDue, MAX(AnnualRevenue) FROM Customer  GROUP BY TotalDue

   See Aggregate Functions for details.
10. Summarize data:
    

    SELECT TotalDue, MAX(AnnualRevenue) FROM Customer GROUP BY TotalDue

    See Aggregate Functions for details.
11. Retrieve data from multiple tables.
    

    SELECT Customers.ContactName, Orders.OrderDate FROM Customers, Orders WHERE Customers.CustomerId=Orders.CustomerId

    See JOIN Queries for details.
12. Sort a result set in ascending order:
    

    SELECT Name, TotalDue FROM Customer  ORDER BY TotalDue ASC

13. Restrict a result set to the specified number of rows:
    

    SELECT Name, TotalDue FROM Customer LIMIT 10 

14. Parameterize a query to pass in inputs at execution time. This enables you to create prepared statements and mitigate SQL injection attacks.
    

    SELECT * FROM Customer WHERE CustomerId = @param

See Explicitly Caching Data for information on using the SELECT statement in offline mode.

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 Couchbase.

    SELECT * FROM Customer WHERE PSEUDO = '@PSEUDO'