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 Workers

2. Rename a column:
   

   SELECT [WorkerID] AS MY_WorkerID FROM Workers

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

   SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM Workers

4. Search data:
   

   SELECT * FROM Workers WHERE AssociateOID = 'G3349PZGBADQY8H8'

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

   SELECT COUNT(*) AS MyCount FROM Workers 

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

   SELECT COUNT(DISTINCT WorkerID) FROM Workers 

7. Return the unique items matching the query criteria:
   

   SELECT DISTINCT WorkerID FROM Workers 

8. Summarize data:
   

   SELECT WorkerID, MAX(AnnualRevenue) FROM Workers GROUP BY WorkerID

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

   SELECT w.WorkerID, w.WorkerOriginalHireDate, a.ItemID, a.ActualStartDate FROM Workers w INNER JOIN WorkersWorkAssignments a ON w.AssociateOID = a.AssociateOID

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

    SELECT AssociateOID, WorkerID FROM Workers  ORDER BY WorkerID ASC

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

    SELECT AssociateOID, WorkerID FROM Workers 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 Workers WHERE AssociateOID = @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 ADP.

    SELECT * FROM Workers WHERE AsOfDate = '2020-01-01'