text: exports.up = function(knex) {
      return knex.schema.createTable("classes", t => {
          t.increments("id").primary()
          t.string("subject").notNull()
          t.decimal("price").notNull()
          t.integer("proffy_id", 10)
              .notNull()
              .unsigned()
              .references("id")
              .inTable("proffies")
              .onUpdate("CASCADE")
              .onDelete("CASCADE")
      })
  };
  
  exports.down = function(knex) {
    return knex.schema.dropTable("classes")
  };