Module: SchemaPlus::ActiveRecord::ConnectionAdapters::MysqlAdapter

Defined in:
lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb

Overview

SchemaPlus includes a MySQL implementation of the AbstractAdapter extensions. (This works with both the mysql</t> and <tt>mysql2 gems.)

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object

:enddoc:



11
12
13
14
15
16
17
18
19
20
21
22
23
24
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 11

def self.included(base)
  base.class_eval do
    alias_method_chain :tables, :schema_plus
    alias_method_chain :remove_column, :schema_plus
    alias_method_chain :rename_table, :schema_plus
    alias_method_chain :exec_stmt, :schema_plus rescue nil # only defined for mysql not mysql2
  end

  if ::ActiveRecord::VERSION::MAJOR.to_i >= 4
    base.class_eval do
      include ::ActiveRecord::ConnectionAdapters::SchemaStatements::AddIndex
    end
  end
end

Instance Method Details

#default_expr_valid?(expr) ⇒ Boolean

Returns:

  • (Boolean) 


150
151
152
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 150

def default_expr_valid?(expr)
  false # only the TIMESTAMP column accepts SQL column defaults and rails uses DATETIME
end

#drop_table(name, options = {}) ⇒ Object

implement cascade by removing foreign keys



57
58
59
60
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 57

def drop_table(name, options={})
  reverse_foreign_keys(name).each{ |foreign_key| remove_foreign_key(foreign_key.table_name, foreign_key.name) } if options[:cascade]
  super
end

#exec_stmt_with_schema_plus(sql, name, binds, &block) ⇒ Object

used only for mysql not mysql2. the quoting methods on ActiveRecord::DB_DEFAULT are sufficient for mysql2



44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 44

def exec_stmt_with_schema_plus(sql, name, binds, &block)
  if binds.any?{ |col, val| val.equal? ::ActiveRecord::DB_DEFAULT}
    binds.each_with_index do |(col, val), i|
      if val.equal? ::ActiveRecord::DB_DEFAULT
        sql = sql.sub(/(([^?]*?){#{i}}[^?]*)\?/, "\\1DEFAULT")
      end
    end
    binds = binds.reject{|col, val| val.equal? ::ActiveRecord::DB_DEFAULT}
  end
  exec_stmt_without_schema_plus(sql, name, binds, &block)
end

#foreign_keys(table_name, name = nil) ⇒ Object 



66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 66

def foreign_keys(table_name, name = nil)
  results = execute("SHOW CREATE TABLE #{quote_table_name(table_name)}", name)

  table_name = table_name.to_s
  namespace_prefix = table_namespace_prefix(table_name)

  foreign_keys = []

  results.each do |row|
    row[1].lines.each do |line|
      if line =~ /^  CONSTRAINT [`"](.+?)[`"] FOREIGN KEY \([`"](.+?)[`"]\) REFERENCES [`"](.+?)[`"] \((.+?)\)( ON DELETE (.+?))?( ON UPDATE (.+?))?,?$/
        name = $1
        column_names = $2
        references_table_name = $3
        references_table_name = namespace_prefix + references_table_name if table_namespace_prefix(references_table_name).blank?
        references_column_names = $4
        on_update = $8
        on_delete = $6
        on_update = on_update ? on_update.downcase.gsub(' ', '_').to_sym : :restrict
        on_delete = on_delete ? on_delete.downcase.gsub(' ', '_').to_sym : :restrict

        foreign_keys << ForeignKeyDefinition.new(name,
                                                 namespace_prefix + table_name, column_names.gsub('`', '').split(', '),
                                                 references_table_name, references_column_names.gsub('`', '').split(', '),
                                                 on_update, on_delete)
      end
    end
  end

  foreign_keys
end

#remove_column_with_schema_plus(table_name, column_name) ⇒ Object 



30
31
32
33
34
35
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 30

def remove_column_with_schema_plus(table_name, column_name)
  foreign_keys(table_name).select { |foreign_key| foreign_key.column_names.include?(column_name.to_s) }.each do |foreign_key|
    remove_foreign_key(table_name, foreign_key.name)
  end
  remove_column_without_schema_plus(table_name, column_name)
end

#remove_foreign_key(table_name, foreign_key_name, options = {}) ⇒ Object 



62
63
64
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 62

def remove_foreign_key(table_name, foreign_key_name, options = {})
  execute "ALTER TABLE #{quote_table_name(table_name)} DROP FOREIGN KEY #{foreign_key_name}"
end

#rename_table_with_schema_plus(oldname, newname) ⇒ Object 



37
38
39
40
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 37

def rename_table_with_schema_plus(oldname, newname)
  rename_table_without_schema_plus(oldname, newname)
  rename_indexes_and_foreign_keys(oldname, newname)
end

#reverse_foreign_keys(table_name, name = nil) ⇒ Object 



98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 98

def reverse_foreign_keys(table_name, name = nil)
  results = execute(<<-SQL, name)
SELECT constraint_name, table_name, column_name, referenced_table_name, referenced_column_name
  FROM information_schema.key_column_usage
 WHERE table_schema = #{table_schema_sql(table_name)}
   AND referenced_table_schema = table_schema
 ORDER BY constraint_name, ordinal_position;
  SQL
  current_foreign_key = nil
  foreign_keys = []

  namespace_prefix = table_namespace_prefix(table_name)

  results.each do |row|
    next unless table_name_without_namespace(table_name).casecmp(row[3]) == 0
    if current_foreign_key != row[0]
        referenced_table_name = row[1]
        referenced_table_name = namespace_prefix + referenced_table_name if table_namespace_prefix(referenced_table_name).blank?
        references_table_name = row[3]
        references_table_name = namespace_prefix + references_table_name if table_namespace_prefix(references_table_name).blank?
      foreign_keys << ForeignKeyDefinition.new(row[0], referenced_table_name, [], references_table_name, [])
      current_foreign_key = row[0]
    end

    foreign_keys.last.column_names << row[2]
    foreign_keys.last.references_column_names << row[4]
  end

  foreign_keys
end

#sql_for_function(function) ⇒ Object 



154
155
156
157
158
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 154

def sql_for_function(function)
  case function
  when :now then 'CURRENT_TIMESTAMP'
  end
end

#tables_with_schema_plus(name = nil, *args) ⇒ Object 



26
27
28
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 26

def tables_with_schema_plus(name=nil, *args)
  tables_without_schema_plus(name, *args) - views(name)
end

#view_definition(view_name, name = nil) ⇒ Object 



137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 137

def view_definition(view_name, name = nil)
  result = execute("SELECT view_definition, check_option FROM information_schema.views WHERE table_schema = SCHEMA() AND table_name = #{quote(view_name)}", name)
  return nil unless (result.respond_to?(:num_rows) ? result.num_rows : result.to_a.size) > 0 # mysql vs mysql2
  row = result.respond_to?(:fetch_row) ? result.fetch_row : result.first
  sql = row[0]
  sql.gsub!(%r{#{quote_table_name(current_database)}[.]}, '')
  case row[1]
  when "CASCADED" then sql += " WITH CASCADED CHECK OPTION"
  when "LOCAL" then sql += " WITH LOCAL CHECK OPTION"
  end
  sql
end

#views(name = nil) ⇒ Object 



129
130
131
132
133
134
135
 
# File 'lib/schema_plus/active_record/connection_adapters/mysql_adapter.rb', line 129

def views(name = nil)
  views = []
  execute("SELECT table_name FROM information_schema.views WHERE table_schema = SCHEMA()", name).each do |row|
    views << row[0]
  end
  views
end