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# frozen-string-literal: true
module Sequel
module Plugins
# The column_select plugin changes the default selection for a
# model dataset to explicit select all columns from the table:
# <tt>table.column1, table.column2, table.column3, ...</tt>.
# This makes it simpler to add columns to the model's table
# in a migration concurrently while running the application,
# without it affecting the operation of the application.
#
# Note that by default on databases that supporting RETURNING,
# using explicit column selections will cause instance creations
# to use two queries (insert and refresh) instead of a single
# query using RETURNING. You can use the insert_returning_select
# plugin to automatically use RETURNING for instance creations
# for models where the column_select plugin automatically sets up
# an explicit column selection.
#
# Usage:
#
# # Make all model subclasses explicitly select qualified columns
# Sequel::Model.plugin :column_select
#
# # Make the Album class select qualified columns
# Album.plugin :column_select
module ColumnSelect
# Modify the current model's dataset selection, if the model
# has a dataset.
def self.configure(model)
model.instance_exec do
self.dataset = dataset if @dataset
end
end
module ClassMethods
private
# If the underlying dataset selects from a single table and
# has no explicit selection, explicitly select all columns from that table,
# qualifying them with table's name.
def convert_input_dataset(ds)
ds = super
unless ds.opts[:select]
if db.supports_schema_parsing?
cols = check_non_connection_error(false){db.schema(ds)}
if cols
cols = cols.map{|c, _| c}
end
end
if cols ||= check_non_connection_error(false){ds.columns}
ds = ds.select(*cols.map{|c| Sequel.qualify(ds.first_source, Sequel.identifier(c))})
end
end
ds
end
end
end
end
end
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