Class: Mysql2postgres::MysqlReader::Table

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql2postgres/mysql_reader.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reader, name) ⇒ Table

Returns a new instance of Table.



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# File 'lib/mysql2postgres/mysql_reader.rb', line 14

def initialize(reader, name)
  @reader = reader
  @name = name
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/mysql2postgres/mysql_reader.rb', line 12

def name
  @name
end

Instance Method Details

#columns ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 19

def columns
  @columns ||= load_columns
end

#convert_type(type) ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 23

def convert_type(type)
  case type
  when /int.* unsigned/, /bigint/
    'bigint'
  when 'bit(1)', 'tinyint(1)'
    'boolean'
  when /tinyint/
    'tinyint'
  when /int/
    'integer'
  when /varchar/, /set/
    'varchar'
  when /char/
    'char'
  when /decimal/
    'decimal'
  when /(float|double)/
    'double precision'
  else
    type
  end
end

#count_for_pager ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 145

def count_for_pager
  query = id? ? 'MAX(id)' : 'COUNT(*)'
  @reader.query "SELECT #{query} FROM `#{name}`" do |res|
    return res.fetch_row[0].to_i
  end
end

#count_rows ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 135

def count_rows
  @reader.query "SELECT COUNT(*) FROM `#{name}`" do |res|
    return res.fetch_row[0].to_i
  end
end

#foreign_keys ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 83

def foreign_keys
  load_indexes unless @foreign_keys
  @foreign_keys
end

#id? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mysql2postgres/mysql_reader.rb', line 141

def id?
  !!columns.find { |col| col[:name] == 'id' }
end

#indexes ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 78

def indexes
  load_indexes unless @indexes
  @indexes
end

#load_columns ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 46

def load_columns
  @reader.reconnect
  # mysql_flags = ::Mysql::Field.constants.select { |c| c.to_s.include?('FLAG') }

  fields = []
  @reader.query "EXPLAIN `#{name}`" do |res|
    while (field = res.fetch_row)
      length = field[1][/\((\d+)\)/, 1] if field[1].match?(/\((\d+)\)/)
      length = field[1][/\((\d+),(\d+)\)/, 1] if field[1].match?(/\((\d+),(\d+)\)/)
      desc = {
        name: field[0],
        table_name: name,
        type: convert_type(field[1]),
        length: length&.to_i,
        decimals: field[1][/\((\d+),(\d+)\)/, 2],
        null: field[2] == 'YES',
        primary_key: field[3] == 'PRI',
        auto_increment: field[5] == 'auto_increment'
      }
      desc[:default] = field[4] unless field[4].nil?
      fields << desc
    end
  end

  fields.select { |field| field[:auto_increment] }.each do |field|
    @reader.query "SELECT max(`#{field[:name]}`) FROM `#{name}`" do |res|
      field[:maxval] = res.fetch_row[0].to_i
    end
  end
  fields
end

#load_indexes ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 88

def load_indexes
  @indexes = []
  @foreign_keys = []

  @reader.query "SHOW CREATE TABLE `#{name}`" do |result|
    explain = result.fetch_row[1]
    explain.split("\n").each do |line|
      next unless line.include? ' KEY '

      index = {}
      if (match_data = /CONSTRAINT `(\w+)` FOREIGN KEY \((.*?)\) REFERENCES `(\w+)` \((.*?)\)(.*)/.match(line))
        index[:name] = "fk_#{name}_#{match_data[1]}"
        index[:column] = match_data[2].delete!('`').split(', ')
        index[:ref_table] = match_data[3]
        index[:ref_column] = match_data[4].delete!('`').split(', ')

        the_rest = match_data[5]

        if (match_data = /ON DELETE (SET NULL|SET DEFAULT|RESTRICT|NO ACTION|CASCADE)/.match(the_rest))
          index[:on_delete] = match_data[1]
        else
          index[:on_delete] ||= 'RESTRICT'
        end

        if (match_data = /ON UPDATE (SET NULL|SET DEFAULT|RESTRICT|NO ACTION|CASCADE)/.match(the_rest))
          index[:on_update] = match_data[1]
        else
          index[:on_update] ||= 'RESTRICT'
        end

        @foreign_keys << index
      elsif (match_data = /KEY `(\w+)` \((.*)\)/.match(line))
        # index[:name] = 'idx_' + name + '_' + match_data[1]
        # with redmine we do not want prefix idx_tablename_
        index[:name] = match_data[1]
        index[:columns] = match_data[2].split(',').map { |col| col[/`(\w+)`/, 1] }
        index[:unique] = true if line.include? 'UNIQUE'
        @indexes << index
      elsif (match_data = /PRIMARY KEY .*\((.*)\)/.match(line))
        index[:primary] = true
        index[:columns] = match_data[1].split(',').map { |col| col.strip.delete '`' }
        @indexes << index
      end
    end
  end
end

#query_for_pager ⇒ Object 



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# File 'lib/mysql2postgres/mysql_reader.rb', line 152

def query_for_pager
  query = id? ? 'WHERE id >= ? AND id < ?' : 'LIMIT ?,?'

  cols = columns.map do |c|
    if c[:type] == 'multipolygon'
      "AsWKT(`#{c[:name]}`) as `#{c[:name]}`"
    else
      "`#{c[:name]}`"
    end
  end

  "SELECT #{cols.join ', '} FROM `#{name}` #{query}"
end