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BulkSqlUtil::BulkInsertOperation Class Reference

base class for bulk DML insert operations More...

`#include <BulkInsertOperation.qc.dox.h>`

Inheritance diagram for BulkSqlUtil::BulkInsertOperation:
[legend]

## Public Member Functions

| constructor (SqlUtil::AbstractTable target, *hash opts)
| creates the object from the supplied arguments More...
| constructor (SqlUtil::Table target, *hash opts)
| creates the object from the supplied arguments More...
| setRowCode (*code rowc)
| sets a closure or call reference that will be called when data has been sent to the database and all output data is available; must accept a hash argument that represents the data written to the database including any output arguments. This code will be reset, once the transaction is commited. More...
Public Member Functions inherited from BulkSqlUtil::AbstractBulkOperation
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...

## Protected Member Functions

| flushImpl ()
| inserts internally-queued queued data in the database with bulk DML operations More...
| init (*hash opts)
| common constructor initialization
| setupInitialRow (hash row)
| sets up support for "returning" insert options for any possible rowcode member
| setupInitialRowColumns (hash row)
| sets up the block buffer given the initial template hash of lists for inserting
Protected Member Functions inherited from BulkSqlUtil::AbstractBulkOperation
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

## Protected Attributes

*code | rowcode
| per-row Closures or Call References for inserts
hash | static_ret_expr
| hash of "returning" arguments
AbstractSQLStatement | stmt
| statement for DML
Protected Attributes inherited from BulkSqlUtil::AbstractBulkOperation
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

## Additional Inherited Members

Public Attributes inherited from BulkSqlUtil::AbstractBulkOperation
const | OptionDefaults = ...
| default option values
const | OptionKeys = ...
| option keys for this object

## Detailed Description

base class for bulk DML insert operations

This class assists with bulk inserts into a target table.

Submitting Data
  To use this class, 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.

Retrieving Data From Inserts
  It is possible to use sql_iop_funcs in the hashes submitted with queueData(); in this case the BulkInsertOperation class assumes that every row has the same operations as in the first row. Output data can then be processed by using the `rowcode` option in the constructor() or by calling setRowCode().
  In case sql_iop_funcs are used and a `rowcode` option is set, then the SQL DML query for inserts is creating using the `"returning"` insert option, therefore the DBI driver in this case must support this option as well.

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();
{
BulkInsertOperation op1(table1);
BulkInsertOperation op2(table2);
# 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.

## Member Function Documentation

## constructor() [1/2]

BulkSqlUtil::BulkInsertOperation::constructor | ( | SqlUtil::AbstractTable | target,
|  | *hash | opts
| ) |  |

creates the object from the supplied arguments

Parameters

  target | the target table object

  opts

  an optional hash of options for the object as follows:
  - `"info_log"`: an optional info logging callback; must accept a string format specifier and sprintf()-style arguments
  - `"block_size"`: the number of rows executed at once (default: 1000)
  - `"rowcode"`: a per-row Closures or Call References for batch inserts; this must take a single hash argument and will be called for every row after a bulk insert; the hash argument representing the row inserted will also contain any output values if applicable (for example if sql_iop_funcs are used in the row hashes submitted to queueData())

See also
  setRowCode()

## constructor() [2/2]

BulkSqlUtil::BulkInsertOperation::constructor | ( | SqlUtil::Table | target,
|  | *hash | opts
| ) |  |

creates the object from the supplied arguments

Parameters

  target | the target table object

  opts

  an optional hash of options for the object as follows:
  - `"info_log"`: an optional info logging callback; must accept a string format specifier and sprintf()-style arguments
  - `"block_size"`: the number of rows executed at once (default: 1000)
  - `"rowcode"`: a per-row Closures or Call References for batch inserts; this must take a single hash argument and will be called for every row after a bulk insert; the hash argument representing the row inserted will also contain any output values if applicable (for example if sql_iop_funcs are used in the row hashes submitted to queueData())

See also
  setRowCode()

## flushImpl()

BulkSqlUtil::BulkInsertOperation::flushImpl | ( |  | ) |

protected virtual

inserts internally-queued queued data in the database with bulk DML operations

This method sets up the SQL DML query used for inserts when row is queued. Output values are only retrieved if sql_iop_funcs are used and a `rowcode` closure or call reference has been set beforehand in the constructor() or by calling setRowCode() and the underlying DBI driver supports the `"returning"` insert option.

Implements BulkSqlUtil::AbstractBulkOperation.

## setRowCode()

BulkSqlUtil::BulkInsertOperation::setRowCode | ( | *code | rowc | ) |

sets a closure or call reference that will be called when data has been sent to the database and all output data is available; must accept a hash argument that represents the data written to the database including any output arguments. This code will be reset, once the transaction is commited.

Example:
  # single commit and rollback
  on_success ds.commit();
  on_error ds.rollback();
  code rowcode = sub (hash row) {
  # process row data
  };
  inserter.setRowCode(rowcode);
  {
  # each operation needs to be flushed or discarded individually
  on_success inserter.flush();
  on_error inserter.discard();
  # data is queued and flushed automatically when the buffer is full
  map inserter.queueData($1), data.iterator();
  }

Parameters

  rowc | a closure or call reference that will be called when data has been sent to the database and all output data is available; must accept a hash argument that represents the data written to the database including any output arguments

Note
  - the per-row closure or call reference can also be set by using the `"rowcode"` option in the constructor()
  - if this method is not called before the first row is queued then output values will not be retrieved; the initial query is built when the template row is queued and output values are only retrieved if a `rowcode` closure or call reference is set beforehand