module PostgreSQLCursor::ActiveRecord::SqlCursor
Public Instance Methods
Public: Like each_row
, but returns an instantiated model object to the block
Paramaters: same as each_row
Example:
Post.each_instance { |post| post.process }
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 32 def each_instance(options={}, &block) options = {:connection => self.connection}.merge(options) all.each_instance(options, &block) end
Public: Like each_row_batch
, but yields an array of instantiated model objects to the block
Parameters: same as each_row
Example:
Post.each_instance_batch { |batch| Post.process_batch(batch) }
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 101 def each_instance_batch(options={}, &block) options = {:connection => self.connection}.merge(options) all.each_instance_batch(options, &block) end
Public: Yields each batch up to block_size of rows as model instances to the given block
As this instantiates a model object, it is slower than each_row_batch_by_sql
Paramaters: see each_row_by_sql
Example:
Post.each_instance_batch_by_sql("select * from posts") do |batch| Post.process_batch(batch) end Post.each_instance_batch_by_sql("select * from posts").map do |batch| Post.transform_batch(batch) end
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 144 def each_instance_batch_by_sql(sql, options={}, &block) options = {:connection => self.connection}.merge(options) cursor = PostgreSQLCursor::Cursor.new(sql, options) return cursor.each_instance_batch(self, &block) if block_given? cursor.iterate_type(self).iterate_batched end
Public: Returns each row as a model instance to the given block As this instantiates a model object, it is slower than each_row_by_sql
Paramaters: see each_row_by_sql
Example:
Post.each_instance_by_sql("select * from posts") { |post| post.process } Post.each_instance_by_sql("select * from posts").count
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 70 def each_instance_by_sql(sql, options={}, &block) options = {:connection => self.connection}.merge(options) cursor = PostgreSQLCursor::Cursor.new(sql, options) return cursor.each_instance(self, &block) if block_given? cursor.iterate_type(self) end
Public: Executes the query, returning each row as a hash to the given block.
options - Hash to control
fraction: 0.1..1.0 - The cursor_tuple_fraction (default 1.0) block_size: 1..n - The number of rows to fetch per db block fetch while: value - Exits loop when block does not return this value. until: value - Exits loop when block returns this value. with_hold: boolean - Allows the query to remain open across commit points.
Example:
Post.each_row { |hash| Post.process(hash) }
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 18 def each_row(options={}, &block) options = {:connection => self.connection}.merge(options) all.each_row(options, &block) end
Public: Executes the query, yielding an array of up to block_size rows where each row is a hash to the given block.
Parameters: same as each_row
Example:
Post.each_row_batch { |batch| Post.process_batch(batch) }
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 86 def each_row_batch(options={}, &block) options = {:connection => self.connection}.merge(options) all.each_row_batch(options, &block) end
Public: Yields each batch of up to block_size rows as an array of rows where each row as a hash to the given block
Parameters: see each_row_by_sql
Example:
Post.each_row_batch_by_sql("select * from posts") do |batch| Post.process_batch(batch) end Post.each_row_batch_by_sql("select * from posts").map do |batch| Post.transform_batch(batch) end
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 120 def each_row_batch_by_sql(sql, options={}, &block) options = {:connection => self.connection}.merge(options) cursor = PostgreSQLCursor::Cursor.new(sql, options) return cursor.each_row_batch(&block) if block_given? cursor.iterate_batched end
sql - Full SQL statement, variables interpolated options - Hash to control
fraction: 0.1..1.0 - The cursor_tuple_fraction (default 1.0) block_size: 1..n - The number of rows to fetch per db block fetch while: value - Exits loop when block does not return this value. until: value - Exits loop when block returns this value. with_hold: boolean - Allows the query to remain open across commit points.
Example:
Post.each_row_by_sql("select * from posts") { |hash| Post.process(hash) } Post.each_row_by_sql("select * from posts").count
Returns the number of rows yielded to the block
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 52 def each_row_by_sql(sql, options={}, &block) options = {:connection => self.connection}.merge(options) cursor = PostgreSQLCursor::Cursor.new(sql, options) return cursor.each_row(&block) if block_given? cursor end
Returns an array of the given column names. Use if you need cursors and don't expect this to comsume too much memory. Values are instance types. Like ActiveRecord's pluck.
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 161 def pluck_instances(*cols) options = cols.last.is_a?(Hash) ? cols.pop : {} all.each_instance(options).pluck(*cols) end
Returns an array of the given column names. Use if you need cursors and don't expect this to comsume too much memory. Values are strings. Like ActiveRecord's pluck.
# File lib/postgresql_cursor/active_record/sql_cursor.rb, line 153 def pluck_rows(*cols) options = cols.last.is_a?(Hash) ? cols.pop : {} all.each_row(options).pluck(*cols) end