Class: JDBCHelper::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/jdbc-helper/connection.rb,
lib/jdbc-helper/connection/row.rb,
lib/jdbc-helper/connection/type_map.rb,
lib/jdbc-helper/connection/result_set.rb,
lib/jdbc-helper/connection/statement_pool.rb,
lib/jdbc-helper/connection/callable_statement.rb,
lib/jdbc-helper/connection/prepared_statement.rb,
lib/jdbc-helper/connection/parameterized_statement.rb

Overview

p_upd.close

Defined Under Namespace

Classes: CallableStatement, ParameterizedStatement, PreparedStatement, ResultSet, Row, StatementPool, Transaction

Constant Summary collapse

RUBY_SQL_TYPE_MAP = 
{
  Fixnum => java.sql.Types::INTEGER,
  Bignum => java.sql.Types::BIGINT,
  String => java.sql.Types::VARCHAR,
  Float  => java.sql.Types::DOUBLE,
  Time   => java.sql.Types::TIMESTAMP
}
GETTER_MAP = 
{
  java.sql.Types::TINYINT                   => :getInt,
  java.sql.Types::SMALLINT                  => :getInt,
  java.sql.Types::INTEGER                   => :getInt,
  java.sql.Types::BIGINT                    => :getLong,

  java.sql.Types::CHAR                      => :getString,
  java.sql.Types::VARCHAR                   => :getString,
  java.sql.Types::LONGVARCHAR               => :getString,
  (java.sql.Types::NCHAR        rescue nil) => :getString,
  (java.sql.Types::NVARCHAR     rescue nil) => :getString,
  (java.sql.Types::LONGNVARCHAR rescue nil) => :getString,

  # !! MySQL function returns VARBINARY type
  java.sql.Types::BINARY             => :getBinaryStream,
  java.sql.Types::VARBINARY          => :getBinaryStream,
  java.sql.Types::LONGVARBINARY      => :getBinaryStream,

  java.sql.Types::REAL               => :getDouble,
  java.sql.Types::FLOAT              => :getFloat,
  java.sql.Types::DOUBLE             => :getDouble,

  java.sql.Types::DATE               => :getDate,
  java.sql.Types::TIME               => :getTime,
  java.sql.Types::TIMESTAMP          => :getTimestamp,

  java.sql.Types::BLOB               => :getBlob,
  java.sql.Types::CLOB               => :getString,
  (java.sql.Types::NCLOB rescue nil) => :getString,

  java.sql.Types::BOOLEAN            => :getBoolean
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = {}) ⇒ Connection

Creates a database connection.

  • ‘args` hash must include :driver (or “driver”) and :url (or “url”)

  • and takes optional :user and :password tuples (or “user”, “password”)

  • You can also specify :timeout (or “timeout”) to override the default connection timeout (60 seconds)

Must be closed explicitly if not used. If a block is given, the connection is automatically closed after executing the block.

Parameters:

  • args (Hash) (defaults to: {})

Raises:

  • (ArgumentError) 


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# File 'lib/jdbc-helper/connection.rb', line 138

def initialize(args = {})
  # Subsequent deletes should not affect the input
  @args = args
  args = InsensitiveHash[ @args ]

  raise ArgumentError.new("driver not given") unless args.has_key? :driver
  raise ArgumentError.new("url not given") unless args.has_key? :url

  @driver = args.delete :driver
  @url = args.delete :url

  # NameError will be thrown for invalid drivers
  Java::JavaClass.for_name @driver

  timeout = args.has_key?(:timeout) ? args.delete(:timeout) : Constants::DEFAULT_LOGIN_TIMEOUT
  if timeout
    if timeout.is_a?(Fixnum) == false || timeout <= 0
      raise ArgumentError.new("Timeout must be a positive integer")
    end
    Java::java.sql.DriverManager.setLoginTimeout timeout
  end

  props = Java::java.util.Properties.new
  args.each do |k, v|
    props.setProperty(k.to_s, v.to_s) if v
  end

  @conn = Java::java.sql.DriverManager.get_connection(@url, props)
  @spool = StatementPool.send :new, self
  @bstmt = nil
  @fetch_size = nil

  @pstmts = []

  @table_wrappers = {}

  if block_given?
    begin
      yield self
    ensure
      close rescue nil
    end
  end
end

Instance Attribute Details

#driver ⇒ String (readonly)

JDBC driver of the connection

Returns:

  • (String) 


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# File 'lib/jdbc-helper/connection.rb', line 120

def driver
  @driver
end

#fetch_size ⇒ Fixnum

Returns the fetch size of the connection. If not set, nil is returned.

Returns:

  • (Fixnum) 


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# File 'lib/jdbc-helper/connection.rb', line 375

def fetch_size
  @fetch_size
end

#url ⇒ String (readonly)

JDBC URL of the connection

Returns:

  • (String) 


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# File 'lib/jdbc-helper/connection.rb', line 116

def url
  @url
end

Instance Method Details

#add_batch(qstr) ⇒ NilClass

Adds a statement to be executed in batch Adds to the batch

Parameters:

  • qstr (String)

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 318

def add_batch(qstr)
  check_closed

  @bstmt ||= @spool.take
  @bstmt.add_batch qstr
end

#clear_batch ⇒ NilClass

Clears the batched statements including prepared statements.

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 347

def clear_batch
  check_closed

  if @bstmt
    @bstmt.clear_batch
    @spool.give @bstmt
    @bstmt = nil
  end

  @pstmts.each do |stmt|
    stmt.clear_batch
  end
end

#clone ⇒ JDBCHelper::Connection

Creates another connection with the same parameters as this Connection.

Returns:



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# File 'lib/jdbc-helper/connection.rb', line 185

def clone
  nc = JDBCHelper::Connection.new @args
  nc.fetch_size = @fetch_size if @fetch_size
  nc
end

#close ⇒ NilClass

Closes the connection

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 379

def close
  return if closed?
  @spool.close
  @conn.close
  @conn = @spool = nil
end

#closed? ⇒ Boolean

Returns if this connection is closed or not

Returns:

  • (Boolean) 


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# File 'lib/jdbc-helper/connection.rb', line 388

def closed?
  @conn.nil?
end

#execute(qstr) ⇒ Fixnum|ResultSet

Executes an SQL and returns the count of the update rows or a ResultSet object depending on the type of the given statement. If a ResultSet is returned, it must be enumerated or closed.

Parameters:

  • qstr (String) —

    SQL string

Returns:



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# File 'lib/jdbc-helper/connection.rb', line 249

def execute(qstr)
  check_closed

  stmt = @spool.take
  begin
    if stmt.execute(qstr)
      ResultSet.send(:new, stmt.getResultSet) { @spool.give stmt }
    else
      rset = stmt.getUpdateCount
      @spool.give stmt
      rset
    end
  rescue Exception => e
    @spool.give stmt
    raise
  end
end

#execute_batch ⇒ Fixnum

Executes batched statements including prepared statements. No effect when no statement is added

Returns:

  • (Fixnum) —

    Sum of all update counts



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# File 'lib/jdbc-helper/connection.rb', line 327

def execute_batch
  check_closed

  cnt = 0

  if @bstmt
    cnt += @bstmt.execute_batch.inject(:+) || 0
    @spool.give @bstmt
    @bstmt = nil
  end

  @pstmts.each do |pstmt|
    cnt += pstmt.execute_batch
  end

  cnt
end

#function(func_name) ⇒ JDBCHelper::FunctionWrapper

Returns a function wrapper for the given function name

Parameters:

  • func_name (String/Symbol) —

    Name of the function to be wrapped

Returns:

Since:

  • 0.2.2



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# File 'lib/jdbc-helper/connection.rb', line 415

def function func_name
  JDBCHelper::FunctionWrapper.new self, func_name
end

#inspect ⇒ String

Returns:

  • (String) 


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# File 'lib/jdbc-helper/connection.rb', line 428

def inspect
  InsensitiveHash[@args].merge({ :closed? => closed? }).tap { |c|
    c.delete(:password)
  }.inspect
end

#jdbc_conn ⇒ Object Also known as: java_obj, java

Returns the underlying JDBC Connection object. Only use this when you really need to access it directly.



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# File 'lib/jdbc-helper/connection.rb', line 124

def jdbc_conn
  @conn
end

#prepare(qstr) ⇒ Object

Creates a prepared statement, which is also an encapsulation of Java PreparedStatement object

Parameters:

  • qstr (String) —

    SQL string



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# File 'lib/jdbc-helper/connection.rb', line 193

def prepare(qstr)
  check_closed

  pstmt = PreparedStatement.send(:new, self, qstr, @conn.prepare_statement(qstr))
  pstmt.set_fetch_size @fetch_size if @fetch_size

  @pstmts << pstmt
  pstmt
end

#prepare_call(qstr) ⇒ Object

Creates a callable statement.

Parameters:

  • qstr (String) —

    SQL string



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# File 'lib/jdbc-helper/connection.rb', line 210

def prepare_call(qstr)
  check_closed

  CallableStatement.send(:new, self, qstr, @conn.prepare_call(qstr))
end

#prepared_statements ⇒ Array

Returns Prepared statements currently opened for this connection.

Returns:

  • (Array) —

    Prepared statements currently opened for this connection



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# File 'lib/jdbc-helper/connection.rb', line 204

def prepared_statements
  @pstmts
end

#procedure(proc_name) ⇒ JDBCHelper::ProcedureWrapper

Returns a procedure wrapper for the given procedure name

Parameters:

  • proc_name (String/Symbol) —

    Name of the procedure to be wrapped

Returns:

Since:

  • 0.3.0



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# File 'lib/jdbc-helper/connection.rb', line 423

def procedure proc_name
  JDBCHelper::ProcedureWrapper.new self, proc_name
end

#query(qstr) {|JDBCHelper::Connection::Row| ... } ⇒ Array Also known as: enumerate

Executes a select query. When a code block is given, each row of the result is passed to the block one by one. If not given, ResultSet is returned, which can be used to enumerate through the result set. ResultSet is closed automatically when all the rows in the result set is consumed.

Examples:

Nested querying

conn.query("SELECT a FROM T") do | trow |
  conn.query("SELECT * FROM U_#{trow.a}").each_slice(10) do | urows |
    # ...
  end
end

Parameters:

  • qstr (String) —

    SQL string

Yields:

Returns:

  • (Array) 


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# File 'lib/jdbc-helper/connection.rb', line 292

def query(qstr, &blk)
  check_closed

  stmt = @spool.take
  begin
    rset = stmt.execute_query(qstr)
  rescue Exception => e
    @spool.give stmt
    raise
  end

  enum = ResultSet.send(:new, rset) { @spool.give stmt }
  if block_given?
    enum.each do |row|
      yield row
    end
  else
    enum
  end
end

#sequence(sequence_name) ⇒ JDBCHelper::SequenceWrapper

Returns a sequence wrapper for the given name

Parameters:

  • sequence_name (String/Symbol) —

    Name of the sequence to be wrapped

Returns:

Since:

  • 0.4.2



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# File 'lib/jdbc-helper/connection.rb', line 407

def sequence sequence_name
  JDBCHelper::SequenceWrapper.new self, sequence_name
end

#set_fetch_size(fsz) ⇒ NilClass Also known as: fetch_size=

Gives the JDBC driver a hint of the number of rows to fetch from the database by a single interaction. This is only a hint. It may have no effect at all.

Parameters:

  • fsz (Fixnum)

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 365

def set_fetch_size(fsz)
  check_closed

  @fetch_size = fsz
  @spool.each { | stmt | stmt.set_fetch_size @fetch_size }
end

#table(table_name) ⇒ JDBCHelper::TableWrapper Also known as: []

Returns a table wrapper for the given table name

Parameters:

  • table_name (String/Symbol) —

    Name of the table to be wrapped

Returns:

Since:

  • 0.2.0



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# File 'lib/jdbc-helper/connection.rb', line 396

def table table_name
  table = JDBCHelper::TableWrapper.new(self, table_name)
  table = table.fetch_size(@fetch_size) if @fetch_size
  @table_wrappers[table_name] ||= table
end

#transaction {|JDBCHelper::Connection::Transaction| ... } ⇒ Boolean

Executes the given code block as a transaction. Returns true if the transaction is committed. A transaction object is passed to the block, which only has commit and rollback methods. The execution breaks out of the code block when either of the methods is called.

Yields:

Returns:

  • (Boolean) —

    True if committed

Raises:

  • (ArgumentError) 


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# File 'lib/jdbc-helper/connection.rb', line 221

def transaction
  check_closed

  raise ArgumentError.new("Transaction block not given") unless block_given?
  tx = Transaction.send :new, @conn
  ac = @conn.get_auto_commit
  status = :unknown
  begin
    @conn.set_auto_commit false
    yield tx
    @conn.commit
    status = :committed
  rescue Transaction::Commit
    status = :committed
  rescue Transaction::Rollback
    status = :rolledback
  ensure
    @conn.rollback if status == :unknown && @conn.get_auto_commit == false
    @conn.set_auto_commit ac
  end
  status == :committed
end

#update(qstr) ⇒ Fixnum

Executes an update and returns the count of the updated rows.

Parameters:

  • qstr (String) —

    SQL string

Returns:

  • (Fixnum) —

    Count of affected records



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# File 'lib/jdbc-helper/connection.rb', line 270

def update(qstr)
  check_closed

  @spool.with do | stmt |
    ret = stmt.execute_update(qstr)
  end
end