If nothing else, Sequel makes it easy to send raw SQL:

DB["SELECT `AUTO_INCREMENT` FROM  INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'DatabaseName' AND TABLE_NAME = 'TableName'"]

From the documentation:

Using raw SQL

DB.run "CREATE TABLE users (name VARCHAR(255) NOT NULL, age INT(3) NOT NULL)"
dataset = DB["SELECT age FROM users WHERE name = ?", name]
dataset.map(:age)
DB.fetch("SELECT name FROM users") do |row|
  p row[:name]
end

If nothing else, Sequel makes it easy to send raw SQL:

DB["SELECT `AUTO_INCREMENT` FROM  INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'DatabaseName' AND TABLE_NAME = 'TableName'"]

From the documentation:

Using raw SQL

DB.run "CREATE TABLE users (name VARCHAR(255) NOT NULL, age INT(3) NOT NULL)"
dataset = DB["SELECT age FROM users WHERE name = ?", name]
dataset.map(:age)
DB.fetch("SELECT name FROM users") do |row|
  p row[:name]
end