BulkSqlUtil::AbstractBulkOperation Class Reference

base class for bulk DML operations More...

Inheritance diagram for BulkSqlUtil::AbstractBulkOperation:

Public Member Methods
nothing	commit ()
	flushes any queued data and commits the transaction
	constructor (string name, SqlUtil::AbstractTable target, *hash opts)
	creates the object from the supplied arguments More...
	constructor (string name, SqlUtil::Table target, *hash opts)
	creates the object from the supplied arguments More...
	destructor ()
	throws an exception if there is data pending in the internal row data cache; make sure to call flush() or discard() before destroying the object More...
	discard ()
	discards any buffered batched data; this method should be called before destroying the object if an error occurs More...
	flush ()
	flushes any remaining batched data to the database; this method should always be called before committing the transaction or destroying the object More...
Qore::SQL::AbstractDatasource	getDatasource ()
	returns the AbstractDatasource object associated with this object
int	getRowCount ()
	returns the affected row count
SqlUtil::AbstractTable	getTable ()
	returns the underlying SqlUtil::AbstractTable object
string	getTableName ()
	returns the table name
	queueData (hash data)
	queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction More...
	queueData (list l)
	queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction More...
nothing	rollback ()
	discards any queued data and rolls back the transaction
int	size ()
	returns the current size of the cache as a number of rows More...

Public Attributes
const	OptionDefaults = ...
	default option values
const	OptionKeys = ...
	option keys for this object

Private Member Methods
abstract	flushImpl ()
	flushes queued data to the database
	flushIntern ()
	flushes queued data to the database
	init (*hash opts)
	common constructor initialization
	setupInitialRow (hash row)
	sets up the block buffer given the initial template row for inserting
	setupInitialRowColumns (hash row)
	sets up the block buffer given the initial template hash of lists for inserting

Private Attributes
softint	block_size
	bulk operation block size
hash	cval
	"constant" row values; must be equal in all calls to queueData
list	cval_keys
	"constant" row value keys
hash	hbuf
	buffer for bulk operations
*code	info_log
	an optional info logging callback; must accept a sprintf()-style format specifier and optional arguments
string	opname
	operation name
list	ret_args = ()
	list of "returning" columns
int	row_count = 0
	row count
SqlUtil::AbstractTable	table
	the target table object

Detailed Description

base class for bulk DML operations

This is an abstract base class for bulk DML operations; this class provides the majority of the API support for bulk DML operations for the concrete child classes that inherit it.

Submitting Data

To use this class's API, queue data in the form of a hash (a single row or a set of rows) or a list of rows by calling the queueData() method.

The queueData() method queues data to be written to the database; the queue is flush()ed automatically when block_size rows have been queued.

Flushing and Discarding Data

Each call to flush() (whether implicit or explicit) will cause a single call to be made to the dataserver; all queued rows are sent in a single bulk DML call, which allows for efficient processing of large amounts of data.

A call to flush() must be made before committing the transaction to ensure that any remaining rows in the internal queue have been written to the database. Because the destructor() will throw an exception if any data is left in the internal queue when the object is destroyed, a call to discard() must be made prior to the destruction of the object in case of errors.

# single commit and rollback
on_success ds.commit();
on_error ds.rollback();
{
    # each operation needs to be flushed or discarded individually
    on_success {
        op1.flush();
        op2.flush();
    }
    on_error {
        op1.discard();
        op2.discard();
    }
 
    # data is queued and flushed automatically when the buffer is full
    map op1.queueData($1), data1.iterator();
    map op2.queueData($1), data2.iterator();
}

Note

• Each bulk DML object must be manually flush()ed before committing or manually discard()ed before rolling back to ensure that all data is managed properly in the same transaction and to ensure that no exception is thrown in the destructor(). See the example above for more information.
• If the underlying driver does not support bulk operations, then such support is emulated with single SQL operations; in such cases performance will be reduced. Call SqlUtil::AbstractTable::hasArrayBind() to check at runtime if the driver supports bulk SQL operations.

Member Function Documentation

constructor() [1/2]

BulkSqlUtil::AbstractBulkOperation::constructor	(	string	name,
		SqlUtil::AbstractTable	target,
		*hash	opts
	)

creates the object from the supplied arguments

Parameters

name	the name of the operation
target	the target table object
opts	an optional hash of options for the object as follows: "block_size": the number of rows executed at once (default: 1000) "info_log": an optional info logging callback; must accept a string format specifier and sprintf()-style arguments

constructor() [2/2]

BulkSqlUtil::AbstractBulkOperation::constructor	(	string	name,
		SqlUtil::Table	target,
		*hash	opts
	)

creates the object from the supplied arguments

Parameters

name	the name of the operation
target	the target table object
opts	an optional hash of options for the object as follows: "block_size": the number of rows executed at once (default: 1000) "info_log": an optional info logging callback; must accept a string format specifier and sprintf()-style arguments

destructor()

BulkSqlUtil::AbstractBulkOperation::destructor

(

)

throws an exception if there is data pending in the internal row data cache; make sure to call flush() or discard() before destroying the object

Exceptions

BLOCK-ERROR

there is unflushed data in the internal row data cache; make sure to call flush() or discard() before destroying the object

discard()

BulkSqlUtil::AbstractBulkOperation::discard

(

)

discards any buffered batched data; this method should be called before destroying the object if an error occurs

Example:

# single commit and rollback
on_success ds.commit();
on_error ds.rollback();
{
    # each operation needs to be flushed or discarded individually
    on_success {
        op1.flush();
        op2.flush();
    }
    on_error {
        op1.discard();
        op2.discard();
    }
 
    # data is queued and flushed automatically when the buffer is full
    map op1.queueData($1), data1.iterator();
    map op2.queueData($1), data2.iterator();
}

Note

• make sure to call flush() before committing the transaction or discard() before rolling back the transaction or destroying the object when using this method
• flush() or discard() needs to be executed individually for each bulk operation object used in the block whereas the DB transaction needs to be committed or rolled back once per datasource

See also

• queueData()
• flush()

flush()

BulkSqlUtil::AbstractBulkOperation::flush

(

)

flushes any remaining batched data to the database; this method should always be called before committing the transaction or destroying the object

Example:

# single commit and rollback
on_success ds.commit();
on_error ds.rollback();
{
    # each operation needs to be flushed or discarded individually
    on_success {
        op1.flush();
        op2.flush();
    }
    on_error {
        op1.discard();
        op2.discard();
    }
 
    # data is queued and flushed automatically when the buffer is full
    map op1.queueData($1), data1.iterator();
    map op2.queueData($1), data2.iterator();
}

Note

• make sure to call flush() before committing the transaction or discard() before rolling back the transaction or destroying the object when using this method
• flush() or discard() needs to be executed individually for each bulk operation object used in the block whereas the DB transaction needs to be committed or rolled back once per datasource

See also

• queueData()
• discard()

queueData() [1/2]

BulkSqlUtil::AbstractBulkOperation::queueData

(

hash

data

)

queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction

Example:

# single commit and rollback
on_success ds.commit();
on_error ds.rollback();
{
    # each operation needs to be flushed or discarded individually
    on_success {
        op1.flush();
        op2.flush();
    }
    on_error {
        op1.discard();
        op2.discard();
    }
 
    # data is queued and flushed automatically when the buffer is full
    map op1.queueData($1), data1.iterator();
    map op2.queueData($1), data2.iterator();
}

Parameters

data

the input record or record set in case a hash of lists is passed; each hash represents a row (keys are column names and values are column values); when inserting, SQL Insert Operator Functions can also be used. If at least one hash value is a list, then any non-hash (indicating an insert opertor hash) and non-list values will be assumed to be constant values for every row and therefore future calls of this method (and overloaded variants) will ignore any values given for such keys and use the values given in the first call.

Note

• the first row passed is taken as a template row; every other row must always have the same keys in the same order, otherwise the results are unpredictable
• if any SQL Insert Operator Functions are used, then they are assumed to be identical in every row
• make sure to call flush() before committing the transaction or discard() before rolling back the transaction or destroying the object when using this method
• flush() or discard() needs to be executed individually for each bulk operation object used in the block whereas the DB transaction needs to be committed or rolled back once per datasource

See also

• flush()
• discard()

queueData() [2/2]

BulkSqlUtil::AbstractBulkOperation::queueData

(

list

l

)

queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction

Example:

# single commit and rollback
on_success ds.commit();
on_error ds.rollback();
{
    # each operation needs to be flushed or discarded individually
    on_success {
        op1.flush();
        op2.flush();
    }
    on_error {
        op1.discard();
        op2.discard();
    }
 
    # data is queued and flushed automatically when the buffer is full
    map op1.queueData($1), data1.iterator();
    map op2.queueData($1), data2.iterator();
}

Parameters

l	a list of hashes representing the input row data; each hash represents a row (keys are column names and values are column values); when inserting, SQL Insert Operator Functions can also be used

Note

• the first row passed is taken as a template row; every other row must always have the same keys in the same order, otherwise the results are unpredictable
• if any SQL Insert Operator Functions are used, then they are assumed to be identical in every row
• make sure to call flush() before committing the transaction or discard() before rolling back the transaction or destroying the object when using this method
• flush() or discard() needs to be executed individually for each bulk operation object used in the block whereas the DB transaction needs to be committed or rolled back once per datasource

See also

• flush()
• discard()

size()

int BulkSqlUtil::AbstractBulkOperation::size

(

)

returns the current size of the cache as a number of rows

Returns

the current size of the cache as a number of rows

Since

BulkSqlUtil 1.2