新建标签:command + t
关闭标签:command + w
切换标签:command + 数字 command + 左右方向键
查看历史命令:command + ;
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查找:command + f
清空当前行(无论光标在什么位置):ctrl + u
deftableUser.arel_tableendusers.where(users[:name].eq('amy'))# SELECT * FROM users WHERE users.name = 'amy'
Arel可以方便定义各种运算符 =, !=, <, >, <=, >=, IN:
users.where(users[:age].eq(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" = 10
users.where(users[:age].not_eq(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" != 10
users.where(users[:age].lt(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" < 10
users.where(users[:age].gt(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" > 10
users.where(users[:age].lteq(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" <= 10
users.where(users[:age].gteq(10)).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" >= 10
users.where(users[:age].in([20,16,17])).project(Arel.sql('*'))# => SELECT * FROM "users" WHERE "users"."age" IN (20, 16, 17)
联表查询也很方便
users.join(photos).on(users[:id].eq(photos[:user_id]))# => SELECT * FROM users INNER JOIN photos ON users.id = photos.user_id