Module: ActiveRecord::ConnectionAdapters::MySQL::SchemaStatements

Included in:
AbstractMysqlAdapter
Defined in:
activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb

Overview

:nodoc:

Instance Method Summary collapse

Instance Method Details

#create_schema_dumper(options) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 96

def create_schema_dumper(options)
  MySQL::SchemaDumper.create(self, options)
end

#create_table(table_name, options: default_row_format) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 80

def create_table(table_name, options: default_row_format, **)
  super
end

#indexes(table_name) ⇒ Object

Returns an array of indexes for the given table.


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 8

def indexes(table_name)
  indexes = []
  current_index = nil
  execute_and_free("SHOW KEYS FROM #{quote_table_name(table_name)}", "SCHEMA") do |result|
    each_hash(result) do |row|
      if current_index != row[:Key_name]
        next if row[:Key_name] == "PRIMARY" # skip the primary key
        current_index = row[:Key_name]

        mysql_index_type = row[:Index_type].downcase.to_sym
        case mysql_index_type
        when :fulltext, :spatial
          index_type = mysql_index_type
        when :btree, :hash
          index_using = mysql_index_type
        end

        indexes << [
          row[:Table],
          row[:Key_name],
          row[:Non_unique].to_i == 0,
          [],
          lengths: {},
          orders: {},
          type: index_type,
          using: index_using,
          comment: row[:Index_comment].presence
        ]
      end

      if row[:Expression]
        expression = row[:Expression]
        expression = +"(#{expression})" unless expression.start_with?("(")
        indexes.last[-2] << expression
        indexes.last[-1][:expressions] ||= {}
        indexes.last[-1][:expressions][expression] = expression
        indexes.last[-1][:orders][expression] = :desc if row[:Collation] == "D"
      else
        indexes.last[-2] << row[:Column_name]
        indexes.last[-1][:lengths][row[:Column_name]] = row[:Sub_part].to_i if row[:Sub_part]
        indexes.last[-1][:orders][row[:Column_name]] = :desc if row[:Collation] == "D"
      end
    end
  end

  indexes.map do |index|
    options = index.pop

    if expressions = options.delete(:expressions)
      orders = options.delete(:orders)
      lengths = options.delete(:lengths)

      columns = index[-1].to_h { |name|
        [ name.to_sym, expressions[name] || +quote_column_name(name) ]
      }

      index[-1] = add_options_for_index_columns(
        columns, order: orders, length: lengths
      ).values.join(", ")
    end

    IndexDefinition.new(*index, **options)
  end
end

#internal_string_options_for_primary_keyObject


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 84

def internal_string_options_for_primary_key
  super.tap do |options|
    if !row_format_dynamic_by_default? && CHARSETS_OF_4BYTES_MAXLEN.include?(charset)
      options[:collation] = collation.sub(/\A[^_]+/, "utf8")
    end
  end
end

#remove_column(table_name, column_name, type = nil, **options) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 73

def remove_column(table_name, column_name, type = nil, **options)
  if foreign_key_exists?(table_name, column: column_name)
    remove_foreign_key(table_name, column: column_name)
  end
  super
end

#table_alias_lengthObject


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 124

def table_alias_length
  256 # https://dev.mysql.com/doc/refman/en/identifiers.html
end

#type_to_sql(type, limit: nil, precision: nil, scale: nil, size: limit_to_size(limit, type), unsigned: nil) ⇒ Object

Maps logical Rails types to MySQL-specific data types.


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 101

def type_to_sql(type, limit: nil, precision: nil, scale: nil, size: limit_to_size(limit, type), unsigned: nil, **)
  sql =
    case type.to_s
    when "integer"
      integer_to_sql(limit)
    when "text"
      type_with_size_to_sql("text", size)
    when "blob"
      type_with_size_to_sql("blob", size)
    when "binary"
      if (0..0xfff) === limit
        "varbinary(#{limit})"
      else
        type_with_size_to_sql("blob", size)
      end
    else
      super
    end

  sql = "#{sql} unsigned" if unsigned && type != :primary_key
  sql
end

#update_table_definition(table_name, base) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb', line 92

def update_table_definition(table_name, base)
  MySQL::Table.new(table_name, base)
end