Ruby/OpenBase Reference

Using Ruby/OpenBase

Typically using Ruby/OpenBase is connecting to database and executing SQL statement with OpenBase object. If you execute SQL statement with OpenBase#execute(), you can get OpenBaseResult object to access query result table as return value. Next, call fetch() or each() to fetching result rows. A simple example is the following.

require 'openbase'

# connects to database
ob = OpenBase.new('WOMovies', 'localhost', 'admin', '')

# executes SQL statement
result = ob.execute 'select * from MOVIE'

# shows result rows
result.each do |row|
  p row
end

Class OpenBase

This class services connecting and communicating to database.

Class Methods

new( database='', host='localhost', login_name='', password='' ): Creates an object and connects to the database.

Instance Methods

(Getting information of the database)

database: Returns the database name.
host: Returns the host name.
login: Returns the login name.
password: Returns the password.
encoding: Returns the encoding.

(Scheme Information)

tables: Returns an array of all table names.
columns( table ): Returns an array of column names of specified table.
relationships( table ): Returns an array of relationships of specified table.

(Connecting to the database)

connect( database='', host='localhost', login_name='', password='' ): Connects to the database.
invalidate: Invalidates connection of the database.
connect?: Returns true if the receiver is connected to the database, or false.

(Executing SQL statements)

execute( statement ): Executes the SQL statement and returns an OpenBaseResult object.

(Using Transaction)

transaction { |connection| ... }: Executes the block with the receiver after starting a new transaction. If the block don't raise exception, the receiver commits the transaction, or rollbacks. If the receiver already has a transaction, executes the block after commiting the transaction.
begin: Starts a new transaction.
commit: Commits the transaction.
rollback: Rollbacks the transaction.
transaction?: Returns true if the receiver has a transcation in progress, or false.

(Generating unique row IDs)

unique_row_id( table, column = '' ): Generates a unique _rowid for the table and column. The _rowid must be inserted with a new record. You need not use the method to insert a new record because of _rowid is used by OpenBase.

Class OpenBaseResult

This class services accessing query result table.

Instance Methods

(Accessing query result table)

column_count: Returns count of the columns.
rows_affected: Returns the number of database rows affected by the most recent SQL statement.
column_infos: Returns an array of OpenBaseColumnInfo objects.

(Fetching)

fetch: Returns a row as array fetched from the database. If there are no more result rows in the database, returns nil.
each { |row| ... }: Fetches each result row.
free: Frees memory used for result row.

Class OpenBaseColumnInfo

This class services accessing information of column.

Instance Methods

name: Returns name of the column..
type: Returns data type of the column.
table: Returns table name of the column.