Class: TableWarnings::Column

Inherits:
Object
  • Object
show all
Defined in:
lib/table_warnings/column.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(table, name) ⇒ Column

Returns a new instance of Column.



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# File 'lib/table_warnings/column.rb', line 6

def initialize(table, name)
  @table = table
  @name = name.to_s
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/table_warnings/column.rb', line 4

def name
  @name
end

#table ⇒ Object (readonly)

Returns the value of attribute table.



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# File 'lib/table_warnings/column.rb', line 3

def table
  @table
end

Instance Method Details

#association ⇒ Object 



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# File 'lib/table_warnings/column.rb', line 59

def association
  return @association.first if @association.is_a?(Array) # ruby needs an easy way to memoize things that might be false or nil
  @association = table.reflect_on_all_associations(:belongs_to).select do |assoc|
    assoc.foreign_key == name
  end
  if @association.many?
    raise ArgumentError, "More than one association on #{table.name} uses foreign key #{name.inspect}"
  end
  @association.first
end

#blanks?(conditions) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/table_warnings/column.rb', line 19

def blanks?(conditions)
  table.where(conditions).where(["LENGTH(TRIM(#{table.quoted_table_name}.#{name})) = 0"]).count > 0
end

#max ⇒ Object 



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# File 'lib/table_warnings/column.rb', line 41

def max
  table.maximum(name)
end

#min ⇒ Object 



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# File 'lib/table_warnings/column.rb', line 37

def min
  table.minimum(name)
end

#nonexistent_owners?(conditions) ⇒ Boolean

select zip_codes.* from zip_codes left join egrid_subregions on ‘egrid_subregions`.`abbreviation` = zip_codes.`egrid_subregion_abbreviation` where `egrid_subregions`.`abbreviation` is null t.project(’COUNT(*)‘).join(a_t, Arel::Nodes::OuterJoin).on(a_t.eq(t)).where(a_t.eq(nil))

Returns:

  • (Boolean) 


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# File 'lib/table_warnings/column.rb', line 47

def nonexistent_owners?(conditions)
  relation = table.includes(association.name).where(
    table.arel_table[association.foreign_key].not_eq(nil).and(      # not this query's job
    association.klass.arel_table[association.klass.primary_key].eq(nil))  # columns in the right table are set to NULL if they don't exist
  )
  if conditions.empty?
    relation.count > 0
  else
    relation.where(conditions).count > 0
  end
end

#nulls?(conditions) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/table_warnings/column.rb', line 11

def nulls?(conditions)
  table.where(conditions).where(name => nil).count > 0
end

#string? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/table_warnings/column.rb', line 15

def string?
  table.columns_hash[name].try(:type) == :string
end

#values_outside?(min, max, conditions) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/table_warnings/column.rb', line 23

def values_outside?(min, max, conditions)
  t = table.arel_table
  range_conditions = if min and max
    t[name].lt(min).or(t[name].gt(max))
  elsif min
    t[name].lt(min)
  elsif max
    t[name].lt(max)
  else
    raise RuntimeError, "Either max or min or both should be defined"
  end
  table.where(conditions).where(range_conditions.and(t[name].not_eq(nil))).count > 0
end