org.openlowcode.server.data.storage

Interface PersistentStorage

All Known Implementing Classes:

BaseJDBCStorage, DerbyJDBCStorage, MariadDBJDBCStorage

public interface PersistentStorage

the interface to all persistence storage. This manages persistence in table, typically stored in a sql database

Author:

Open Lowcode SAS

Field Summary

Fields

Modifier and Type	Field and Description
static int	INDEX_DIFFERENT value if index is different
static int	INDEX_NOT_PRESENT value if indes is not present at all
static int	INDEX_OK value if index is OK in persistence layer

Method Summary

Modifier and Type	Method and Description
void	closeConnections() close all connections of the persistence layer
void	commitTransaction() in case of manual commit, finishes a transaction
void	createField(StoredTableSchema object, int fieldindex) creates the n-th field of the specified object
void	createObject(StoredTableSchema object) creates a new table in the persistence layer
void	createSearchIndex(java.lang.String name, StoredTableSchema object, StoredFieldSchema[] fields, boolean unique)
void	createSequence(java.lang.String sequencename, int firstvalue) creates a unique sequence in the database
void	DeleteOnDB(DeleteQuery dq) deletes a single line in the database
boolean	DoesFieldExist(StoredTableSchema object, int fieldindex)
int	DoesIndexExist(StoredTableSchema object, StoredFieldSchema[] fields, java.lang.String name) checks if the index exists and indexes the specified fields
boolean	DoesObjectExist(StoredTableSchema object) Introspection of the datamodel: checks if the table exists
void	dropIndex(java.lang.String name) drops the index as specified by name
int	getNextValue(java.lang.String sequencename) gets the next value from the sequence
void	insertOnDB(StoredTableRow row) Insert a single row in the persistent storage
boolean	isSequenceExisting(java.lang.String sequencename) Checks if a sequence already exists
void	MassiveDeleteOnDB(MultipleTableRow rowstodelete) deletes multiple rows in the persistent storage
void	MassiveInsertOnDB(MultipleTableRow row) Insert multiple rows in the persistent storage
void	MassiveUpdateOnDB(MultipleTableRow row) updates multiple rows in the persistent storage
void	rollbackTransaction() in case of manual commit, rollbacks a transaction
Row	selectOnDB(SelectQuery sq) selects data in the persistent storage
void	setAutoCommit(boolean autocommit) sets the persistence layer as either autocommit (each action is persisted) or manual commit (several actions can be packaged in )
void	startTransaction() in case of manual commit, starts a transaction
void	technicalInit() This method will be played once at the launch of the server.
void	UpdateOnDB(UpdateQuery uq) updates a single line in the database

Field Detail

INDEX_OK

static final int INDEX_OK

value if index is OK in persistence layer

See Also:

Constant Field Values

INDEX_DIFFERENT

static final int INDEX_DIFFERENT

value if index is different

See Also:

Constant Field Values

INDEX_NOT_PRESENT

static final int INDEX_NOT_PRESENT

value if indes is not present at all

See Also:

Constant Field Values

Method Detail

technicalInit

void technicalInit()

This method will be played once at the launch of the server. It serves to initiate workaround for databases that do not support all expected features. Today, this is used to create a table to store sequences for databases that do not support them.

selectOnDB

Row selectOnDB(SelectQuery sq)

selects data in the persistent storage

Parameters:

sq - select query

Returns:

a set of Rows (Row is actually an iterator)

insertOnDB

void insertOnDB(StoredTableRow row)

Insert a single row in the persistent storage

Parameters:

row - the row to insert

MassiveInsertOnDB

void MassiveInsertOnDB(MultipleTableRow row)

Insert multiple rows in the persistent storage

Parameters:

row - multiple rows to insert

MassiveUpdateOnDB

void MassiveUpdateOnDB(MultipleTableRow row)

updates multiple rows in the persistent storage

Parameters:

row - multiple rows to update

MassiveDeleteOnDB

void MassiveDeleteOnDB(MultipleTableRow rowstodelete)

deletes multiple rows in the persistent storage

Parameters:

row - multiple rows to update

UpdateOnDB

void UpdateOnDB(UpdateQuery uq)

updates a single line in the database

Parameters:

uq - query to update a single row

DeleteOnDB

void DeleteOnDB(DeleteQuery dq)

deletes a single line in the database

Parameters:

dq - query to delete a single row

DoesObjectExist

boolean DoesObjectExist(StoredTableSchema object)

Introspection of the datamodel: checks if the table exists

Parameters:

object - the table schema to check

Returns:

true if the table already exists

DoesFieldExist

boolean DoesFieldExist(StoredTableSchema object,
                       int fieldindex)

Parameters:

object - the table schema to check

fieldindex - field to check (by index)

Returns:

dropIndex

void dropIndex(java.lang.String name)

drops the index as specified by name

Parameters:

name - name of the index

DoesIndexExist

int DoesIndexExist(StoredTableSchema object,
                   StoredFieldSchema[] fields,
                   java.lang.String name)

checks if the index exists and indexes the specified fields

Parameters:

object - object to create the index on

fields - ordered list of fields

name - name of the index

Returns:

a value as defined by static int in this class

createObject

void createObject(StoredTableSchema object)

creates a new table in the persistence layer

Parameters:

object - definition (schema) of the stored table

createField

void createField(StoredTableSchema object,
                 int fieldindex)

creates the n-th field of the specified object

Parameters:

object - object definition (schema) of the stored table

fieldindex - index of the field to create

createSearchIndex

void createSearchIndex(java.lang.String name,
                       StoredTableSchema object,
                       StoredFieldSchema[] fields,
                       boolean unique)

Parameters:

name -

object -

fields -

unique -

setAutoCommit

void setAutoCommit(boolean autocommit)

sets the persistence layer as either autocommit (each action is persisted) or manual commit (several actions can be packaged in )

Parameters:

autocommit - true for autocommit, false for manual commit

startTransaction

void startTransaction()

in case of manual commit, starts a transaction

commitTransaction

void commitTransaction()

in case of manual commit, finishes a transaction

rollbackTransaction

void rollbackTransaction()

in case of manual commit, rollbacks a transaction

isSequenceExisting

boolean isSequenceExisting(java.lang.String sequencename)

Checks if a sequence already exists

Parameters:

sequencename - name of the sequence

Returns:

true if the sequence exists, false if the sequence does not exist

createSequence

void createSequence(java.lang.String sequencename,
                    int firstvalue)

creates a unique sequence in the database

Parameters:

sequencename - name of the sequence

firstvalue - first integer value of the sequence

getNextValue

int getNextValue(java.lang.String sequencename)

gets the next value from the sequence

Parameters:

sequencename - name of the sequence

Returns:

the next value

closeConnections

void closeConnections()

close all connections of the persistence layer