Rails 不明白 SQL 怎么会一条一条执行

moyuanming · October 22, 2014 · Last by moyuanming replied at October 24, 2014 · 1854 hits

View ： <% @tollprojects.each do |tollproject| %>

…… SQL ： CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 1 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 2 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."id" = $1 LIMIT 1 [["id", 1]] CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 3 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."id" = $1 LIMIT 1 [["id", 1]] CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 4 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."id" = $1 LIMIT 1 [["id", 1]] CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 5 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."id" = $1 LIMIT 1 [["id", 1]] CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 6 LIMIT 1 CACHE (0.0ms) SELECT "tollprojects".* FROM "tollprojects" WHERE "tollprojects"."tollproject_id" = 7 LIMIT 1

数据多就很慢，不太明白为何要一条记录对应一个查询。是否有其他处理的办法？