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> } .* 
      } [ , ... ] 
  }
  { 
    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 
  | {RANK() | DENSE_RANK()} OVER ([PARTITION BY <column_reference>] {ORDER BY <column_reference>})
  | <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 [CloudObjectStorage_1].[SampleBucket_1].Jobs

2. Rename a column:
   

   SELECT [Status] AS MY_Status FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs

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

   SELECT CAST(AnnualRevenue AS VARCHAR) AS Str_AnnualRevenue FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs

4. Search data:
   

   SELECT * FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs WHERE UserId = '[email protected]'

5. The IBM Cloud Data Engine APIs support the following operators in the WHERE clause: =, >, <, >=, <=, <>, !=, LIKE, NOT LIKE, IN, NOT IN, IS NULL, IS NOT NULL, ANY, ALL, EXISTS, NOT EXISTS, CONTAINS, NOT CONTAINS, BETWEEN, AND, OR.
   

   SELECT * FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs WHERE UserId = '[email protected]';

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

   SELECT COUNT(*) AS MyCount FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs 

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

   SELECT COUNT(DISTINCT Status) FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs 

8. Return the unique items matching the query criteria:
   

   SELECT DISTINCT Status FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs 

9. Sort a result set in ascending order:
   

   SELECT Id, Status FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs  ORDER BY Status ASC

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

    SELECT Id, Status FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs LIMIT 10 

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

    SELECT * FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs WHERE UserId = @param

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 IBM Cloud Data Engine.

    SELECT * FROM [CloudObjectStorage_1].[SampleBucket_1].Jobs WHERE Pseudo = '@Pseudo'
    

Aggregate Functions

For SELECT examples using aggregate functions, see Aggregate Functions.

JOIN Queries

See JOIN Queries for SELECT query examples using JOINs.

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.