FireDAC Components for Azure Data Management

Build 20.0.7587

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> 
    ]
  ] 
}

<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 Subscriptions
  2. Rename a column:
    SELECT [AuthorizationSource] AS MY_AuthorizationSource FROM Subscriptions
  3. Cast a column's data as a different data type:
    SELECT CAST(SubscriptionSpendingLimit AS VARCHAR) AS Str_SubscriptionSpendingLimit FROM Subscriptions
  4. Search data:
    SELECT * FROM Subscriptions WHERE SubscriptionId = 'fadc4-4cdaf-fadc4-4cdaf';
  5. Return the number of items matching the query criteria:
    SELECT COUNT(*) AS MyCount FROM Subscriptions 
  6. Return the number of unique items matching the query criteria:
    SELECT COUNT(DISTINCT AuthorizationSource) FROM Subscriptions 
  7. Return the unique items matching the query criteria:
    SELECT DISTINCT AuthorizationSource FROM Subscriptions 
  8. Summarize data:
    SELECT AuthorizationSource, MAX(SubscriptionSpendingLimit) FROM Subscriptions GROUP BY AuthorizationSource
    See Aggregate Functions for details.
  9. Retrieve data from multiple tables.
    SELECT RateCards.MeterId,RateCards.MeterRateKey,RateCards.MeterRateValue,ConsumptionData.Quantity FROM ConsumptionData,RateCards where ConsumptionData.MeterId=RateCards.MeterId AND StartTime='2014-05-15' AND EndTime='2018-02-15'
    See JOIN Queries for details.
  10. Sort a result set in ascending order:
    SELECT DisplayName, AuthorizationSource FROM Subscriptions  ORDER BY AuthorizationSource ASC
  11. Restrict a result set to the specified number of rows:
    SELECT DisplayName, AuthorizationSource FROM Subscriptions 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 Subscriptions WHERE SubscriptionId = @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 Azure Data Management.

    SELECT * FROM Subscriptions WHERE Pseudo = '@Pseudo'
    

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Build 20.0.7587