Class: CleanSweep::TableSchema

Inherits:
Object
  • Object
show all
Defined in:
lib/clean_sweep/table_schema.rb

Defined Under Namespace

Classes: ColumnSchema, IndexSchema

Instance Attribute Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

- (TableSchema) initialize(model, options = {})

Returns a new instance of TableSchema



15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
 
# File 'lib/clean_sweep/table_schema.rb', line 15

def initialize(model, options={})

  traversing_key_name  = options[:key_name]
  ascending            = options.include?(:ascending) ? options[:ascending] : true
  first_only           = options[:first_only]
  @model               = model
  @dest_model          = options[:dest_model] || @model

  # Downcase and symbolize the entries in the column name map:
  dest_columns_map     = Hash[*(options[:dest_columns] || {}).to_a.flatten.map{|n| n.to_s.downcase.to_sym}]

  @name                = @model.table_name

  @columns      =
    (options[:extra_columns] || []).map do | extra_col_name |
      CleanSweep::TableSchema::ColumnSchema.new extra_col_name, model
    end

  key_schemas = build_indexes

  # Primary key only supported, but we could probably get around this by adding
  # all columns as 'primary key columns'
  @primary_key = find_primary_key(key_schemas)
  raise "Table #{model.table_name} must have a primary key" unless @primary_key

  @primary_key.add_columns_to @columns
  if traversing_key_name
    traversing_key_name.downcase!
    raise "BTREE Index #{traversing_key_name} not found in #@name" unless key_schemas.include? traversing_key_name
    @traversing_key = key_schemas[traversing_key_name]
    @traversing_key.add_columns_to @columns
    @traversing_key.ascending = ascending
    @traversing_key.first_only = first_only
  end

  # Specify the column names in the destination map, if provided
  @columns.each do | column |
    column.dest_name = dest_columns_map[column.name]
  end

end

Instance Attribute Details

- (Object) columns (readonly)

The list of columns used when selecting, the union of pk and traversing key columns



5
6
7
 
# File 'lib/clean_sweep/table_schema.rb', line 5

def columns
  @columns
end

- (Object) name (readonly)

Returns the value of attribute name



13
14
15
 
# File 'lib/clean_sweep/table_schema.rb', line 13

def name
  @name
end

- (Object) primary_key (readonly)

The schema for the primary key



8
9
10
 
# File 'lib/clean_sweep/table_schema.rb', line 8

def primary_key
  @primary_key
end

- (Object) traversing_key (readonly)

The schema for the traversing key, or nil



11
12
13
 
# File 'lib/clean_sweep/table_schema.rb', line 11

def traversing_key
  @traversing_key
end

Instance Method Details

- (Object) column_names 



57
58
59
 
# File 'lib/clean_sweep/table_schema.rb', line 57

def column_names
  @columns.map(&:name)
end

- (Object) delete_statement(rows) 



65
66
67
68
69
70
71
72
73
74
 
# File 'lib/clean_sweep/table_schema.rb', line 65

def delete_statement(rows)
  rec_criteria = rows.map do | row |
    row_compares = []
    @primary_key.columns.each do |column|
      row_compares << "#{column.quoted_dest_name(@dest_model)} = #{column.quoted_value(row)}"
    end
    "(" + row_compares.join(" AND ") + ")"
  end
  "DELETE FROM #{@dest_model.quoted_table_name} WHERE #{rec_criteria.join(" OR ")}"
end

- (Boolean) first_only?

Returns:

  • (Boolean) 


90
91
92
 
# File 'lib/clean_sweep/table_schema.rb', line 90

def first_only?
  @traversing_key && @traversing_key.first_only
end

- (Object) initial_scope 



76
77
78
79
80
 
# File 'lib/clean_sweep/table_schema.rb', line 76

def initial_scope
  scope = @model.all.select(quoted_column_names).from(from_clause)
  scope = @traversing_key.order(scope) if @traversing_key
  return scope
end

- (Object) insert_statement(rows) 



61
62
63
 
# File 'lib/clean_sweep/table_schema.rb', line 61

def insert_statement(rows)
  "insert into #{@dest_model.quoted_table_name} (#{quoted_dest_column_names}) values #{quoted_row_values(rows)}"
end

- (Object) scope_to_next_chunk(scope, last_row) 



82
83
84
85
86
87
88
 
# File 'lib/clean_sweep/table_schema.rb', line 82

def scope_to_next_chunk scope, last_row
  if @traversing_key.blank?
    scope
  else
    @traversing_key.scope_to_next_chunk(scope, last_row)
  end
end