Class: OracleToMysql::Command::WriteAndExecuteMysqlCommandsToBashFile

Inherits:
OracleToMysql::Command show all
Defined in:
lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb

Instance Attribute Summary

Attributes inherited from OracleToMysql::Command

#client_class

Instance Method Summary collapse

Methods inherited from OracleToMysql::Command

#error, #execute, #finished, #info, #output, #started, #warn

Instance Method Details

#command_line_invocation ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 90

def command_line_invocation
  h = self.client_class.otm_target_config_hash
  "mysql -u'#{h['username']}' -h'#{h['host']}' -p'#{h['password']}' #{h['database']} < '#{self.client_class.otm_get_file_name_for(:mysql_commands)}'"
end

#create_actual_target_table_if_it_doesnt_exist ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 50

def create_actual_target_table_if_it_doesnt_exist        
  # If this is the first run, the destination table won't exist yet.  If that's the 
  # case, create an empty table so the atomic rename works
  "create table if not exists #{self.client_class.otm_target_table} 
   select * from #{self.client_class.otm_temp_target_table} where 1=0"
end

#drop_expired_retained_tables ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 57

def drop_expired_retained_tables
  raise "TODO: not implemented yet for retention :n != 1" if tables_to_retain != 1
   "drop table if exists #{self.client_class.otm_retained_target_table(tables_to_retain)}"
end

#execute_internal ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 101

def execute_internal
  bytes_written = 0
  the_mysql_commands_file = self.client_class.otm_get_file_name_for(:mysql_commands)
  File.open(the_mysql_commands_file,'w') do |f|
    bytes_written = f.write(self.the_mysql_commands)
  end
  if bytes_written > 0
    self.info("#{bytes_written} bytes written to #{the_mysql_commands_file}")
  else
    self.error("Could not write to #{the_mysql_commands_file}")
  end

  stderr_str = ""
  stdout_str = ""     
  the_command = self.command_line_invocation
  self.started("mysql child being spawned")
  unless
   Open4::popen4(the_command) { |pid, stdin, stdout, stderr|
     stderr_str = stderr.read
     stdout_str = stdout.read
     true
   }
   self.error("Could not execute #{the_command}")
  end
  self.finished("mysql child terminated")

  if stderr_str.length > 0
    self.error("mysql child process had stderr output: #{stderr_str}")
  end
  if stdout_str.length > 0
    self.warn("mysql child process: #{stdout_str}")
  end      
end

#execute_otm_target_sql ⇒ Object

MYSQL queryies/commands BEGIN



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 22

def execute_otm_target_sql
  self.client_class.otm_target_sql
end

#execute_temp_file_modded_otm_target_sql ⇒ Object

The client class should not have to know about otm_temp_target_table this overrides it just for this instance so the otm_target_sql gets the temp table name interpolated into it instead of the actual this is done this way to support the non-atomic rename strategy as well (which does not create a temp table)



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 31

def execute_temp_file_modded_otm_target_sql      
  the_modded_client_class_inst = self.client_class.clone
  the_modded_client_class_inst.instance_eval(<<-EOS, __FILE__,__LINE__)
    def otm_target_table
      "#{self.client_class.otm_temp_target_table}"
    end
  EOS
  the_modded_client_class_inst.otm_target_sql
end

#load_data_infile ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 41

def load_data_infile
  "-- Rip through the oracle output data and insert into mysql
   load data local infile '#{self.client_class.otm_get_file_name_for(:oracle_output)}' 
   into table #{self.client_class.otm_temp_target_table}
   fields terminated by '\\t'
   lines terminated by '\\n'
  "
end

#mysql_command_order ⇒ Object

Done this way so the child, _in_replace_mode, can override this



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 11

def mysql_command_order
  [:execute_otm_target_sql,
   :execute_temp_file_modded_otm_target_sql,
   :load_data_infile,        
   :drop_expired_retained_tables,
   :perform_atomic_rename_of_tables
  ]
end

#perform_atomic_rename_of_tables ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 62

def perform_atomic_rename_of_tables
  raise "TODO: not implemented yet for retention :n != 1" if tables_to_retain != 1
  "RENAME table 
    #{self.client_class.otm_target_table} TO #{self.client_class.otm_retained_target_table(tables_to_retain)}, 
    #{self.client_class.otm_temp_target_table} TO #{self.client_class.otm_target_table}"
  # rename table #{self.otm_retained_target_table}
  # 
  # 
  # #{self.client_class.otm_target_table} to #{self.client_class.otm_target_table}_old, #{self.client_class.otm_temp_target_table} to #{self.client_class.otm_target_table};
  # 
end

#tables_to_retain ⇒ Object 



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 5

def tables_to_retain
  self.client_class.otm_retain_options[:n]
end

#temp_file_symbols ⇒ Object

overridden from parent to help CleanupTempFilesAndTables do it’s job



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 97

def temp_file_symbols
  [:mysql_commands]
end

#the_mysql_commands ⇒ Object

– Reflect the table retain options #drop_expired_retained_tables_sql;



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# File 'lib/oracle_to_mysql/command/write_and_execute_mysql_commands_to_bash_file.rb', line 80

def the_mysql_commands
  the_queries = ''
  self.mysql_command_order.each do |mysql_command|
    the_queries << "-- #{mysql_command.to_s}\n" # to make debugging easier
    the_queries << self.send(mysql_command)
    the_queries << ";\n"
  end
  the_queries    
end