Module: Sq::Dbsync::Database::Common

Included in:
Mysql, Postgres
Defined in:
lib/sq/dbsync/database/common.rb

Constant Summary collapse

SQD = 
::Sq::Dbsync

Instance Method Summary collapse

Instance Method Details

#__getobj__ ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 52

def __getobj__
  db
end

#__setobj__(db) ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 56

def __setobj__(db)
  @db = db
end

#customize_sql(sql, schema) ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 31

def customize_sql(sql, schema)
  sql
end

#ensure_connection ⇒ Object

Since we go so long without using connections (during a batch load), they go stale and raise DatabaseDisconnectError when we try to use them. This method ensures that the connection is fresh even after a long time between drinks.



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# File 'lib/sq/dbsync/database/common.rb', line 48

def ensure_connection
  db.disconnect
end

#extract_incrementally_to_file(plan, file_name, last_row_at, overlap) ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 15

def extract_incrementally_to_file(plan, file_name, last_row_at, overlap)
  table_name = plan.source_table_name.to_sym
  db_columns = db.schema(table_name).map(&:first)

  query = self[table_name].select(*plan.columns)
  if last_row_at
    query = query.filter("#{plan.timestamp} > ?", last_row_at - overlap)
  end

  sql = query.sql

  sql = customize_sql(sql, db.schema(table_name))

  extract_sql_to_file(sql, file_name)
end

#extract_to_file(table_name, columns, file_name) ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 8

def extract_to_file(table_name, columns, file_name)
  extract_sql_to_file("SELECT %s FROM %s" % [
    columns.join(', '),
    table_name
  ], file_name)
end

#hash_schema(plan) ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 35

def hash_schema(plan)
  ensure_connection
  Hash[schema(plan.source_table_name)]
end

#name ⇒ Object 



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# File 'lib/sq/dbsync/database/common.rb', line 40

def name
  self['SELECT database()'].first.fetch(:'database()')
end