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 HBase adapter:

SELECT {
  [ TOP <numeric_literal> | DISTINCT ]
  { 
    * 
    | { 
        <expression> [ [ AS ] <column_reference> ] 
        | { <table_name> | <correlation_name> } .* 
      } [ , ... ] 
  }
  { 
    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 | LIKE | NOT LIKE | IN | NOT IN } [ <expression> ]
    } [ { AND | OR } ... ]

Examples

Return all columns:
```
SELECT * FROM Account
```
Rename a column:
```
SELECT "Name" AS MY_Name FROM Account
```

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

SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM Account

Search data:

SELECT * FROM Account WHERE Industry = 'Floppy Disks'

The HBase APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, AND, OR, LIKE, NOT LIKE, IN, NOT IN.
```
SELECT * FROM Account WHERE Industry = 'Floppy Disks';
```
Return the number of items matching the query criteria:
```
SELECT COUNT(*) AS MyCount FROM Account 
```
Return the number of unique items matching the query criteria:
```
SELECT COUNT(DISTINCT Name) FROM Account 
```
Return the unique items matching the query criteria:
```
SELECT DISTINCT Name FROM Account 
```

Sort a result set in ascending order:

SELECT Id, Name FROM Account  ORDER BY Name 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 Apache HBase