## 例

`

     void sqlite_create_aggregate ( resource $dbhandle , string $function_name , callback $step_func , callback $finalize_func [, int $num_args = -1 ] )

`

## 説明

Object oriented style (method): void SQLiteDatabase::createAggregate ( string $function_name , callback $step_func , callback $finalize_func [, int $num_args = -1 ] )
sqlite_create_aggregate() is similar to sqlite_create_function() except that it registers functions that can be used to calculate a result aggregated across all the rows of a query. The key difference between this function and sqlite_create_function() is that two functions are required to manage the aggregate; step_func is called for each row of the result set. Your PHP function should accumulate the result and store it into the aggregation context. Once all the rows have been processed, finalize_func will be called and it should then take the data from the aggregation context and return the result. Callback functions should return a type understood by SQLite (i.e. scalar type).

## 戻り値

No value is returned.