1.5 KiB
Executable File
QUERY
The full syntax involves complex manipulations at the row level through scalar functions, data aggregation across preliminary rows via aggregate functions, filtering by aggregation, and row ordering.
NOTE: scalar and aggregate functions are currently under development and not available. Also, these are subject to change.
<scalar-function> ::=
IF <predicate> THEN { <expression> | <scalar-function> }
ELSE { <expression> | <scalar-function> } ENDIF
| CASE <expression>
WHEN { <expression> | <predicate> }
THEN { <expression> | <scalar-function> } [ ...n ]
[ ELSE { <expression> | <scalar-function> } ]
END
| COALESCE ( <expression> [ ,...n ] )
| <arithmetic>
| <bitwise>
| <predicate>
| <boolean>
| <scalar>
If a CASE
expression uses <predicate>
, the expected boolean (or loobean) logic applies. If it uses <expression>
@
0 is treated as false and any other value as true (not loobean). (NOTE: This is preliminary design subject to change.)
COALESCE
returns the first <expression>
in the list that exists. Non-existence occurs when a selected <expression>
value is not returned due to an outer join not matching or <scalar-query>
not returning rows.
See CH 8 Functions for full documentation on Scalars.
<expression> ::=
{ ...
| <aggregate-function>( { <column> | <scalar> } )
}
<aggregate-function> ::=
{ AVG | MAX | MIN | SUM | COUNT | AND | OR | <user-defined> }