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> 
    ]
  ] 
}

<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 Invoices

2. Rename a column:
   

   SELECT [DueDate] AS MY_DueDate FROM Invoices

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

   SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM Invoices

4. Search data:
   

   SELECT * FROM Invoices WHERE Status = 'SENT'

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

   SELECT COUNT(*) AS MyCount FROM Invoices 

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

   SELECT COUNT(DISTINCT DueDate) FROM Invoices 

7. Return the unique items matching the query criteria:
   

   SELECT DISTINCT DueDate FROM Invoices 

8. Summarize data:
   

   SELECT DueDate, MAX(AnnualRevenue) FROM Invoices GROUP BY DueDate

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

   SELECT Invoices.Title, InvoiceItems.TotalValue FROM Invoices, InvoiceItems WHERE Invoices.Id=InvoiceItems.InvoiceId

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

    SELECT Id, DueDate FROM Invoices  ORDER BY DueDate ASC

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

    SELECT Id, DueDate FROM Invoices LIMIT 10 

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

    SELECT * FROM Invoices WHERE Status = @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 Wave Financial.

    SELECT * FROM Invoices WHERE Pseudo = '@Pseudo'