org.makumba
Interface Transaction

All Superinterfaces:

Database

public interface Transaction
extends Database

This class models operations with a database.

Strictly speaking this class represents a database connection. Obtaining more such objects for the same database configurations will result in opening more connections. Connections must be given back to the system using the close() method. That will be done automatically by the object's finalizer. In makumba business logic, connections passed to the BL methods are automatically closed by the system after the BL operations (including eventual automatic DB acceses) were completed. To open a "sibling" of a connection conn of this type, use MakumbaSystem.getConnectionTo(conn.getName()). In most cases, you will have to close the sibling yourself.

At the level of this API, data is represented as java.util.Dictionary, both for reading and writing. Most methods throw DBError if a fatal database error occurs. If the connection to the database is lost, an attempt is made to reconnect before throwing a DBError.

All methods throw subclasses of either Error or RuntimeException, so nothing needs to be caught explicitely.

Since:

makumba-0.5

See Also:

org.makumba.MakumbaSystem#getDefaultDataSourceName(), org.makumba.MakumbaSystem#getDefaultDatabaseName(java.lang.String), MakumbaSystem.getConnectionTo(java.lang.String)

Method Summary

void	close() Give this connection back to the system.
void	commit() Commit the transaction associated with this connection.
void	delete(Pointer ptr) Delete the record pointed by the given pointer.
int	delete(String from, String where, Object parameterValues) Delete in the form delete("general.Person p", "p=$1", params) .
Vector<Dictionary<String,Object>>	executeQuery(String query, Object arguments) Execute query without limiting the results.
Vector<Dictionary<String,Object>>	executeQuery(String query, Object arguments, int offset, int limit) Execute a parametrized OQL query.
String	getDataSource() Returns the name of the data source to which this Transaction is connected
String	getName() Get the name of the database in the form host[_port]_dbprotocol_dbname
org.makumba.providers.TransactionProvider	getTransactionProvider() Returns the TransactionProvider which created this Transaction
Pointer	insert(Pointer host, String subsetField, Dictionary<String,Object> data) Insert a record in a subset (1-N set) of the given record.
Vector<Pointer>	insert(String type, Collection<Dictionary<String,Object>> data) Performs a batch insert.
Pointer	insert(String type, Dictionary<String,Object> data) Insert a record of the given type.
int	insertFromQuery(String type, String OQL, Object parameterValues) Insert the results of the query in the given type.
void	lock(String symbol) Acquire a lock associated to the given application-specific symbol.
Dictionary<String,Object>	read(Pointer ptr, Object fields) Read fields of a record.
Vector<String>	readCharEnumValues(Pointer basePointer, String setName)
Vector<Pointer>	readExternalSetValues(Pointer basePointer, String setName) Convenience method to read all the values of an external set into one Collection.
Vector<Integer>	readIntEnumValues(Pointer basePointer, String setName)
void	rollback() Rollback the transaction associated with this connection.
void	unlock(String symbol) Free the lock on the given symbol, if any exists.
int	update(Pointer ptr, Dictionary<String,Object> fieldsToChange) Change the record pointed by the given pointer.
int	update(String from, String set, String where, Object parameterValues) Update in the form update("general.Person p", "p.birthdate=$1", "p=$2", params) .
int	updateSet(Pointer basePointer, String setName, Collection<?> addElements, Collection<?> removeElements) Convenience method to update the values of an external set.
List<FieldValueDiff>	updateWithValueDiff(Pointer ptr, Dictionary<String,Object> fieldsToChange)

Method Detail

read

Dictionary<String,Object> read(Pointer ptr,
                               Object fields)

Read fields of a record. Database querying is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.query.compilation", "db.query.execution", "db.query.performance" loggers, with Level.INFO logging level. "db.query.execution" also logs Level.SEVERE fatal errors.

Specified by:

read in interface Database

Parameters:

ptr - the pointer to the record

fields - the fields to read, or null to read all fields. Can be a String, String[], Enumeration or a Vector

Returns:

a Dictionary, containing a name-value pair for each non-null field, or null if the record doesn't exist

Throws:

InvalidValueException - if the fields argument is not String, String[], Enumeration or Vector

DBError - if a fatal database error occurs

IllegalStateException - if the connection was already closed

getName

String getName()

Get the name of the database in the form host[_port]_dbprotocol_dbname

Specified by:

getName in interface Database

executeQuery

Vector<Dictionary<String,Object>> executeQuery(String query,
                                               Object arguments,
                                               int offset,
                                               int limit)

Execute a parametrized OQL query. Queries are pre-compiled and cached in the database, so they should be parametrized as much as possible. Database querying is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.query.compilation", "db.query.execution", "db.query.performance" loggers, with Level.INFO logging level. "db.query.execution" also logs Level.SEVERE fatal errors.

Specified by:

executeQuery in interface Database

Parameters:

query - the query to execute. Refers to parameters as $1, $2 ...

arguments - the arguments of the queries. Should be null if there are none. If there is only one parameter, it can be indicated directly. If there are more parameters, they can be indicated in a Object[] or a java.util.Vector. Named parameters can be indicated in a Map.

limit - the maximum number of records to return, -1 for all

offset - the offset of the first record to return, 0 for first

Returns:

a Dictionary, containing a name-value pair for each non-null SELECT column. If a certain SELECT column is not named using AS, it will be automatically named like col1, col2, etc.

Throws:

DBError - if a fatal database error occurs

OQLParseError - if the OQL is not correct

InvalidValueException - in case of makumba type conflict between a pointer value passed as parameter and the type expected in the respective OQL expression

IllegalStateException - if the connection was already closed

executeQuery

Vector<Dictionary<String,Object>> executeQuery(String query,
                                               Object arguments)

Execute query without limiting the results.

Specified by:

executeQuery in interface Database

See Also:

executeQuery(java.lang.String,java.lang.Object,int,int)

insert

Pointer insert(String type,
               Dictionary<String,Object> data)

Insert a record of the given type.
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.

Special makumba fields are treated as follows:

• External sets (sets of records in other tables), as well as sets of int and char can be inserted as Vectors.
  
• Base records and subrecords can be inserted as well. Base records are indicated by fixed, notnull pointers and the record constitutes logical extensions of its base records (this is called subtyping in database theory).
• Subrecords are indicated by 1-1 pointers, and are a logical extension of the record.
• Both base record fields and subrecord fields can be referred to via their pointer, like P.field, where P is a pointer to the base record or a 1-1 pointer. By extension P1.P2.field notations can exist.

Specified by:

insert in interface Database

Parameters:

type - the makumba type to create a new record for

data - the field-value mapping for the new record.
The ommitted fields will be set to null.
To insert an set of integets (set int {...}) pass a Vector of Integers. (or null, or an empty vector).
To insert an set of strings (set char {...}) pass a Vector of String. (or null, or an empty vector).
To refer to a field of base record or subrecord, indicate the pointer that leads to the record, and the respective field, like ptr1.ptr2.field. Every mentioned base record and subrecord will be inserted.

Returns:

a Pointer to the inserted record

Throws:

DBError - if a fatal database error occurs

DataDefinitionNotFoundError - if the indicated type is not found

InvalidValueException - if a certain field does not accept the given value

InvalidValueException - in case of makumba type conflict between a pointer value passed and the definition of the respective field

ClassCastException - in case of java type conflict between a value passed and the definition of the respective field

IllegalStateException - if the connection was already closed

insert

Vector<Pointer> insert(String type,
                       Collection<Dictionary<String,Object>> data)

Performs a batch insert. The way of providing data is the same as for insert(String, Dictionary), only that a collection is provided instead of a single Dictionary.

Parameters:

type - the makumba type to create a new record for

data - a set of field-value mapping for the new record.

Returns:

a Vector containing the pointers of the inserted records, in the order in which they were inserted.

insert

Pointer insert(Pointer host,
               String subsetField,
               Dictionary<String,Object> data)

Insert a record in a subset (1-N set) of the given record.
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.
Special makumba fields are treated as follows:

• The new member's external sets (sets of records in other tables) as well as sets of int and char can be inserted as Vectors.
  
• The new member can have subrecords, but cannot have base records.

Specified by:

insert in interface Database

Parameters:

host - a pointer to the host record, to which a subrecord will be added

subsetField - the name of the subrecord field.

data - the field-value mapping for the new subrecord.
The ommitted fields will be set to null.
To insert an external set, pass a Vector of Pointers (or null, or an empty vector).
To insert an set of integets (set int {...}) pass a Vector of Integers. (or null, or an empty vector).
To insert an set of strings (set char {...}) pass a Vector of String. (or null, or an empty vector).
To refer to a field of a subrecord (subset members cannot have base records), indicate the pointer that leads to the record, and the respective field, like ptr1.ptr2.field.

Returns:

a Pointer to the inserted record

Throws:

DBError - if a fatal database error occurs

InvalidValueException - if a certain value is not valid for a field

InvalidValueException - in case of makumba type conflict between a pointer value passed and the definition of the respective field

ClassCastException - in case of java type conflict between a value passed and the definition of the respective field

IllegalStateException - if the connection was already closed

insertFromQuery

int insertFromQuery(String type,
                    String OQL,
                    Object parameterValues)

Insert the results of the query in the given type. Generates an INSERT...SELECT. The labels of the OQL query must match field names of the given type.

Parameters:

type - the type where to insert

OQL - the OQL query to execute. Refers to parameters as $1, $2 ...

parameterValues - the parameter values. Should be null if there are no parameters. If there is only one parameter, it can be indicated directly. If there are more parameters, they can be indicated in a Object[] or a java.util.Vector

Returns:

the number of records inserted

update

int update(Pointer ptr,
           Dictionary<String,Object> fieldsToChange)

Change the record pointed by the given pointer. Only fields indicated as keys in fieldsToChange are changed to the respective values.
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.

Special makumba fields are treated as follows:

• External sets (sets of records in other tables), as well as sets of intger or char, can be indicated for change as Vectors.
  
• Base records and subrecords can be changed as well. Base records are indicated by fixed, notnull pointers and the record constitutes logical extensions of its base records (this is called subtyping in database theory).
• Subrecords are indicated by 1-1 pointers, and are a logical extension of the record. Both base record fields and subrecord fields can be referred to via their pointer, like P.field, where P is a pointer to the base record or a 1-1 pointer. By extension P1.P2.field notations can exist.

Specified by:

update in interface Database

Parameters:

ptr - pointer to the record to update

fieldsToChange - key-value pairs for the fields to modify.
To nullify a field, pass the respective Null value from the Pointer class.
To change an external set, pass a Vector of Pointers (an empty vector will empty the set).
To change a set of integrers (set int{...}), pass a Vector of Integers (an empty vector will empty the set).
To change a set of integrers (set char{...}), pass a Vector of Strings (an empty vector will empty the set).
To refer to a field of a base record or subrecord, indicate the pointer that leads to the record, and the respective field, like ptr1.ptr2.field.

Throws:

DBError - if a fatal database error occurs

InvalidValueException - if a certain value is not valid for a field

InvalidValueException - in case of makumba type conflict between a pointer value passed and the definition of the respective field

ClassCastException - in case of java type conflict between a value passed and the definition of the respective field

IllegalStateException - if the connection was already closed

See Also:

Pointer.Null, Pointer.NullInteger, Pointer.NullString, Pointer.NullText, Pointer.NullDate, Pointer.NullSet

updateWithValueDiff

List<FieldValueDiff> updateWithValueDiff(Pointer ptr,
                                         Dictionary<String,Object> fieldsToChange)

update

int update(String from,
           String set,
           String where,
           Object parameterValues)

Update in the form update("general.Person p", "p.birthdate=$1", "p=$2", params) .
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.
NOTE that this method does not delete subrecords if their pointers are nullified

Specified by:

update in interface Database

Parameters:

from - a makumba type in which update will take place, for example "general.Person p"

set - the assignments made by the update, as OQL expression e.g. "p.birthdate=$1". Use "nil" for null assignments.

where - the OQL conditions selecting the objects on which the update will be made, e.g. "p=$2"

parameterValues - the parameter values. Should be null if there are no parameters. If there is only one parameter, it can be indicated directly. If there are more parameters, they can be indicated in a Object[] or a java.util.Vector

Returns:

the number of records affected

Throws:

IllegalStateException - if the connection was already closed

DBError - if a fatal database error occurs

Since:

makumba-0.5.5

updateSet

int updateSet(Pointer basePointer,
              String setName,
              Collection<?> addElements,
              Collection<?> removeElements)

Convenience method to update the values of an external set. This method is a shortcut to other Makumba API and Java methods, and basically does the following steps:

1. Read all the existing values of the field setName of the object basePointer into a collection, using readExternalSetValues(Pointer, String)
2. Remove the set elements specified in the parameter deleteElements
3. Add the set elements specified in the parameter newElements
4. Use update(Pointer, Dictionary) to write the new set values to the database

Parameters:

basePointer - pointer to the record to update

setName - the name of the external set in the type of basePointer

addElements - A Collection of String or Pointer (the type can vary for each collection element) of new objects to add to existing set elements

removeElements - A Collection of String or Pointer (the type can vary for each collection element) of objects that should be removed from the existing set elements

Returns:

the number of records affected

readExternalSetValues

Vector<Pointer> readExternalSetValues(Pointer basePointer,
                                      String setName)

Convenience method to read all the values of an external set into one Collection. This method is a shortcut to other Makumba API and Java methods, and basically does the following steps:

1. Run executeQuery(String, Object) to read all the values of the field setName of the object basePointer.
2. Convert the resulting Vector> into a Vector

Parameters:

basePointer - pointer to the record to update

setName - the name of the external set in the type of basePointer

Returns:

A Vector containing the Pointer of the external set

readIntEnumValues

Vector<Integer> readIntEnumValues(Pointer basePointer,
                                  String setName)

readCharEnumValues

Vector<String> readCharEnumValues(Pointer basePointer,
                                  String setName)

delete

void delete(Pointer ptr)

Delete the record pointed by the given pointer. If the pointer is a 1-1, the pointer in the base record is set to null. All the subrecords and subsets are automatically deleted.
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.

Specified by:

delete in interface Database

Parameters:

ptr - the pointer to the record to be deleted

Throws:

DBError - if a fatal database error occurs

IllegalStateException - if the connection was already closed

delete

int delete(String from,
           String where,
           Object parameterValues)

Delete in the form delete("general.Person p", "p=$1", params) .
Database update is logged (see Logger, MakumbaSystem.setLoggingRoot(java.lang.String)) in the "db.update.execution", "db.update.performance" loggers, with Level.INFO logging level. "db.update.execution" also logs Level.SEVERE fatal errors.
NOTE that this method does not delete subsets and subrecords

Specified by:

delete in interface Database

Parameters:

from - a makumba type in which delete will take place, for example "general.Person p"

where - the OQL conditions selecting the objects to be deleted, e.g. "p=$1"

parameterValues - the parameter values. Should be null if there are no parameters. If there is only one parameter, it can be indicated directly. If there are more parameters, they can be indicated in a Object[] or a java.util.Vector

Returns:

the number of records affected

Throws:

DBError - if a fatal database error occurs

IllegalStateException - if the connection was already closed

Since:

makumba-0.5.5

commit

void commit()

Commit the transaction associated with this connection. Normally, simply closing the connection will do, but more often committs may be needed. The business logic manager will close (and therefore commit) all transaction that it provides for usage.

Specified by:

commit in interface Database

close

void close()

Give this connection back to the system. This will automatically commit the transaction if it was not committed. A connection cannot be used after closing.

Specified by:

close in interface Database

Throws:

DBError - if a fatal database error occurs

IllegalStateException - if the connection was already closed

rollback

void rollback()

Rollback the transaction associated with this connection. Typically rollback should be doneif an error occurs in a business logic operation. The business logic manager will rollback a transaction that it provided for usage if it catches any exception during the business logic execution.

Specified by:

rollback in interface Database

lock

void lock(String symbol)

Acquire a lock associated to the given application-specific symbol. This method will block as long as the lock is already taken on another Database object. The commit() and rollback() methods unlcok all locks acquired on this connection

Specified by:

lock in interface Database

unlock

void unlock(String symbol)

Free the lock on the given symbol, if any exists. This will allow the continuation of a thread that needs a lock on the same symbol and uses another Database object

Specified by:

unlock in interface Database

getTransactionProvider

org.makumba.providers.TransactionProvider getTransactionProvider()

Returns the TransactionProvider which created this Transaction

getDataSource

String getDataSource()

Returns the name of the data source to which this Transaction is connected