Class: Rails::Command::QueryCommand

# File 'railties/lib/rails/commands/query/query_command.rb', line 176

def execute_sql(connection:, sql:, page:, per:)
  unless sql.gsub(/--.*$|\/\*.*?\*\//m, "").match?(/\bLIMIT\b/i)
    offset = (page - 1) * per
    sql = "#{sql.rstrip.chomp(';')} LIMIT #{per + 1}"
    sql += " OFFSET #{offset}" if offset > 0
  end

  ar_result = connection.select_all(sql)
  truncated = ar_result.rows.length > per
  { columns: ar_result.columns, rows: ar_result.rows.first(per), sql: sql, truncated: truncated }
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 238

def format_associations(model)
  return unless model

  model.reflect_on_all_associations.map do |assoc|
    hash = {
      type: assoc.macro,
      name: assoc.name,
      class_name: assoc.class_name
    }
    hash[:foreign_key] = assoc.foreign_key if assoc.respond_to?(:foreign_key)
    hash[:through] = assoc.through_reflection.name if assoc.through_reflection?
    hash
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 188

def format_result(columns:, rows:, sql:, elapsed_ms: 0, page: 1, per: rows.length, truncated: false)
  JSON.generate({
    columns: columns,
    rows: rows,
    meta: {
      row_count: rows.length,
      query_time_ms: elapsed_ms,
      page: page,
      per_page: per,
      has_more: truncated,
      sql: sql
    }
  })
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 210

def format_table_detail(connection, table)
  raise ArgumentError, "Table '#{table}' does not exist" unless connection.table_exists?(table)

  columns = connection.columns(table)
  indexes = connection.indexes(table)
  model = model_for_table(table)

  JSON.generate({
    table: table,
    columns: columns.map do |col|
      { name: col.name, type: col.sql_type, null: col.null, default: col.default }
    end,
    indexes: indexes.map do |idx|
      { name: idx.name, columns: idx.columns, unique: idx.unique }
    end,
    enums: model&.defined_enums.presence,
    associations: format_associations(model)
  }.compact)
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 203

def format_table_list(connection)
  tables = connection.tables.sort
  rows = tables.map { |table| [ table ] }

  format_result(columns: [ "table_name" ], rows: rows, sql: "")
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 230

def model_for_table(table)
  Rails.application.eager_load!

  ActiveRecord::Base.descendants.find do |klass|
    !klass.abstract_class? && klass.table_name == table
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 263

def output_error(message)
  error JSON.generate({
    error: message,
    meta: { query_time_ms: 0 }
  })
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 24

def perform(expression = nil, *args)
  boot_application!
  Rails.application.load_runner

  ActiveSupport::Notifications.instrument("query.rails", expression: expression) do
    case expression
    when "schema"
      run_schema(args.first)
    when "models"
      run_models
    when "explain"
      run_explain(args.first)
    else
      run_query(expression)
    end
  end
rescue StandardError, SyntaxError, NotImplementedError => e
  output_error(e.message)
  exit 1
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 141

def reading_role_available?(connection_class)
  connection_class.connected_to(role: :reading) do
    connection_class.lease_connection
  end
  true
rescue ActiveRecord::ConnectionNotEstablished
  false
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 253

def resolve_expression(expression)
  if expression == "-" || (expression.nil? && !$stdin.tty?)
    $stdin.read.strip
  elsif expression
    expression
  else
    raise ArgumentError, "No query expression provided. Run '#{self.class.executable} -h' for help."
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 93

def run_explain(expression = nil)
  expression = resolve_expression(expression)

  if options[:sql]
    with_readonly_connection do |connection|
      result = connection.select_all("EXPLAIN #{expression}")
      say format_result(columns: result.columns, rows: result.rows, sql: "EXPLAIN #{expression}")
    end
  else
    relation = eval(expression, TOPLEVEL_BINDING, "(query)", 1)
    sql = relation.to_sql
    with_readonly_connection_for(relation.model.connection_class_for_self) do |connection|
      result = connection.select_all("EXPLAIN #{sql}")
      say format_result(columns: result.columns, rows: result.rows, sql: "EXPLAIN #{sql}")
    end
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 74

def run_models
  Rails.application.eager_load!

  models = ActiveRecord::Base.descendants
    .reject(&:abstract_class?)
    .select { |model| model.table_name.present? }
    .sort_by(&:name)

  data = models.map do |model|
    {
      model: model.name,
      table_name: model.table_name,
      associations: format_associations(model)
    }
  end

  say JSON.generate(data)
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 46

def run_query(expression)
  expression = resolve_expression(expression)
  page = [ options[:page], 1 ].max
  per = [ [ options[:per], 1 ].max, 10_000 ].min

  start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  result = if options[:sql]
    with_readonly_connection do |connection|
      execute_sql(connection: connection, sql: expression, page: page, per: per)
    end
  else
    execute_ar(expression: expression, page: page, per: per)
  end
  elapsed_ms = ((Process.clock_gettime(Process::CLOCK_MONOTONIC) - start_time) * 1000).round(1)

  say format_result(**result, elapsed_ms: elapsed_ms, page: page, per: per)
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 64

def run_schema(table = nil)
  with_readonly_connection do |connection|
    if table
      say format_table_detail(connection, table)
    else
      say format_table_list(connection)
    end
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 129

def with_explicit_database(database)
  original = ActiveRecord::Base.connection_db_config
  begin
    ActiveRecord::Base.establish_connection(database.to_sym)
    ActiveRecord::Base.while_preventing_writes do
      yield ActiveRecord::Base.lease_connection
    end
  ensure
    ActiveRecord::Base.establish_connection(original)
  end
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 111

def with_readonly_connection(&block)
  with_readonly_connection_for(ActiveRecord::Base, &block)
end

# File 'railties/lib/rails/commands/query/query_command.rb', line 115

def with_readonly_connection_for(connection_class, &block)
  if options[:database]
    with_explicit_database(options[:database], &block)
  elsif reading_role_available?(connection_class)
    connection_class.connected_to(role: :reading) do
      connection_class.with_connection(&block)
    end
  else
    connection_class.while_preventing_writes do
      connection_class.with_connection(&block)
    end
  end
end