nxt.db

Class FullTextTrigger

java.lang.Object

nxt.db.FullTextTrigger

All Implemented Interfaces:

TransactionalDb.TransactionCallback, org.h2.api.Trigger

public class FullTextTrigger
extends java.lang.Object
implements org.h2.api.Trigger, TransactionalDb.TransactionCallback

FullTextTrigger provides Lucene search support. Each searchable database has a database trigger defined. The Lucene index is updated whenever a row is inserted, updated or deleted. The DB_ID column is used to identify each row and will be returned as the COLUMNS and KEYS values in the search results. Schema, table and column names are expected to be in uppercase to match the way H2 stores the information. Function aliases are created in the default schema (PUBLIC) and triggers are created in the schema of the table being indexed. The database aliases are defined as follows: CREATE ALIAS FTL_CREATE_INDEX FOR "nxt.db.FullTextTrigger.createIndex" CALL FTL_CREATE(schema, table, columnList) CREATE ALIAS FTL_DROP_INDEX FOR "nxt.db.FullTextTrigger.dropIndex" CALL FTL_DROP(schema, table) CREATE ALIAS FTL_SEARCH FOR "nxt.db.FullTextTrigger.search" CALL FTL_SEARCH(schema, table, query, limit, offset) FTL_CREATE_INDEX is called to create a fulltext index for a table. It is provided as a convenience for use in NxtDbVersion when creating a new index after the database has been created. FTL_DROP_INDEX is called to drop a fulltext index for a table. It is provided as a convenience for use in NxtDbVersion when dropping a table after the database has been created. FTL_SEARCH is used to return the search result set as part of a SELECT statement. The result set columns are the following: SCHEMA - the schema name (String) TABLE - the table name (String) COLUMNS - the primary key columns (String[]) - this is always DB_ID for NRS KEYS - the primary key values (Long[]) - DB_ID value for the row SCORE - the search hit score (Float) The table index trigger is defined as follows: CREATE TRIGGER trigger_name AFTER INSERT,UPDATE,DELETE ON table_name FOR EACH ROW CALL "nxt.db.FullTextTrigger"

Field Summary

Fields inherited from interface org.h2.api.Trigger

DELETE, INSERT, SELECT, UPDATE

Constructor Summary

Constructors

Constructor and Description
FullTextTrigger()

Method Summary

Modifier and Type	Method and Description
void	close() Close the trigger (Trigger interface)
void	commit() Commit the table changes for the current transaction (TransactionCallback interface)
static void	createIndex(java.sql.Connection conn, java.lang.String schema, java.lang.String table, java.lang.String columnList) Create the fulltext index for a table
static void	dropAll(java.sql.Connection conn) Drop all fulltext indexes
static void	dropIndex(java.sql.Connection conn, java.lang.String schema, java.lang.String table) Drop the fulltext index for a table
void	fire(java.sql.Connection conn, java.lang.Object[] oldRow, java.lang.Object[] newRow) Trigger has fired (Trigger interface)
static void	init(BasicDb db) Initialize the fulltext support for a new database This method should be called from NxtDbVersion when performing the database version update that enables NRS fulltext search support
void	init(java.sql.Connection conn, java.lang.String schema, java.lang.String trigger, java.lang.String table, boolean before, int type) Initialize the trigger (Trigger interface)
static void	migrateToV7(BasicDb db)
static void	reindex(java.sql.Connection conn) Reindex all of the indexed tables
void	remove() Remove the trigger (Trigger interface)
void	rollback() Discard the table changes for the current transaction (TransactionCallback interface)
static java.sql.ResultSet	search(java.sql.Connection conn, java.lang.String schema, java.lang.String table, java.lang.String queryText, int limit, int offset) Search the Lucene index The result set will have the following columns: SCHEMA - Schema name (String) TABLE - Table name (String) COLUMNS - Primary key column names (String[]) - this is always DB_ID KEYS - Primary key values (Long[]) - this is always the DB_ID value for the table row SCORE - Lucene score (Float)
static void	setActive(boolean active) This method is called by NRS initialization to indicate NRS is active.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FullTextTrigger

public FullTextTrigger()

Method Detail

setActive

public static void setActive(boolean active)

This method is called by NRS initialization to indicate NRS is active. This is required since database triggers will be initialized when the database is opened outside the NRS environment (for example, from the H2 console) The database triggers cannot be re-activated after they have been deactivated.

Parameters:

active - TRUE to enable database triggers

init

public static void init(BasicDb db)

Initialize the fulltext support for a new database This method should be called from NxtDbVersion when performing the database version update that enables NRS fulltext search support

Parameters:

db - BasicDb to init

migrateToV7

public static void migrateToV7(BasicDb db)

reindex

public static void reindex(java.sql.Connection conn)
                    throws java.sql.SQLException

Reindex all of the indexed tables

Parameters:

conn - SQL connection

Throws:

java.sql.SQLException - Unable to reindex tables

createIndex

public static void createIndex(java.sql.Connection conn,
                               java.lang.String schema,
                               java.lang.String table,
                               java.lang.String columnList)
                        throws java.sql.SQLException

Create the fulltext index for a table

Parameters:

conn - SQL connection

schema - Schema name

table - Table name

columnList - Indexed column names separated by commas

Throws:

java.sql.SQLException - Unable to create fulltext index

dropIndex

public static void dropIndex(java.sql.Connection conn,
                             java.lang.String schema,
                             java.lang.String table)
                      throws java.sql.SQLException

Drop the fulltext index for a table

Parameters:

conn - SQL connection

schema - Schema name

table - Table name

Throws:

java.sql.SQLException - Unable to drop fulltext index

dropAll

public static void dropAll(java.sql.Connection conn)
                    throws java.sql.SQLException

Drop all fulltext indexes

Parameters:

conn - SQL connection

Throws:

java.sql.SQLException - Unable to drop fulltext indexes

search

public static java.sql.ResultSet search(java.sql.Connection conn,
                                        java.lang.String schema,
                                        java.lang.String table,
                                        java.lang.String queryText,
                                        int limit,
                                        int offset)
                                 throws java.sql.SQLException

Search the Lucene index The result set will have the following columns: SCHEMA - Schema name (String) TABLE - Table name (String) COLUMNS - Primary key column names (String[]) - this is always DB_ID KEYS - Primary key values (Long[]) - this is always the DB_ID value for the table row SCORE - Lucene score (Float)

Parameters:

conn - SQL connection

schema - Schema name

table - Table name

queryText - Query expression

limit - Number of rows to return

offset - Offset with result set

Returns:

Search results

Throws:

java.sql.SQLException - Unable to search the index

init

public void init(java.sql.Connection conn,
                 java.lang.String schema,
                 java.lang.String trigger,
                 java.lang.String table,
                 boolean before,
                 int type)
          throws java.sql.SQLException

Initialize the trigger (Trigger interface)

Specified by:

init in interface org.h2.api.Trigger

Parameters:

conn - Database connection

schema - Database schema name

trigger - Database trigger name

table - Database table name

before - TRUE if trigger is called before database operation

type - Trigger type

Throws:

java.sql.SQLException - A SQL error occurred

close

public void close()

Close the trigger (Trigger interface)

Specified by:

close in interface org.h2.api.Trigger

remove

public void remove()

Remove the trigger (Trigger interface)

Specified by:

remove in interface org.h2.api.Trigger

fire

public void fire(java.sql.Connection conn,
                 java.lang.Object[] oldRow,
                 java.lang.Object[] newRow)

Trigger has fired (Trigger interface)

Specified by:

fire in interface org.h2.api.Trigger

Parameters:

conn - Database connection

oldRow - The old row or null

newRow - The new row or null

commit

public void commit()

Commit the table changes for the current transaction (TransactionCallback interface)

Specified by:

commit in interface TransactionalDb.TransactionCallback

rollback

public void rollback()

Discard the table changes for the current transaction (TransactionCallback interface)

Specified by:

rollback in interface TransactionalDb.TransactionCallback