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 XML adapter:

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> ] 
  } [ , ... ]
  [ 
    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> { = | > | < | >= | <= | <> | != | AND | OR } [ <expression> ]
    } [ { AND | OR } ... ]

Examples

Return all columns:
```
SELECT * FROM NorthwindOData
```

Rename a column:

SELECT "Username" AS MY_Username FROM NorthwindOData

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

SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM NorthwindOData

Search data:

SELECT * FROM NorthwindOData WHERE Email = 'ana.trujilo@northwind.org'

The XML APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, AND, OR.
```
SELECT * FROM NorthwindOData WHERE Email = 'ana.trujilo@northwind.org';
```
Return the number of items matching the query criteria:
```
SELECT COUNT(*) AS MyCount FROM NorthwindOData 
```
Return the number of unique items matching the query criteria:
```
SELECT COUNT(DISTINCT Username) FROM NorthwindOData 
```
Return the unique items matching the query criteria:
```
SELECT DISTINCT Username FROM NorthwindOData 
```

Sort a result set in ascending order:

SELECT Email, Username FROM NorthwindOData  ORDER BY Username ASC

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.

Window Functions

See Window Functions for SELECT examples containing window functions.

Table-Valued Functions

See Table-Valued Functions for SELECT examples with table-valued functions.

TDV Adapter for XML