Question

标记为“使用子查询”的http://www.rethinkdb.com/docs/table-joins/上的示例无法按预期工作。除了关于lambda这个词的拼写错误你能建议修复吗？

Answer 1

http://www.rethinkdb.com/docs/table-joins/中发布的示例是一个Python示例。如果您想在Ruby中试用该示例，请尝试将以下查询输入irb：

r.table("companies").get(id).merge{ |company| { 
     :employees => r.table('employees')
       .get_all(company['id'], :index => 'company_id')
       .coerce_to('array') }
  }.run(Conn)

该查询的结果应如下所示：

irb(main):254:0> r.table("companies").get(id).merge{ |company| {
irb(main):255:2*      :employees => r.table('employees')
irb(main):256:2>        .get_all(company['id'], :index => 'company_id')
irb(main):257:2>        .coerce_to('array') }
irb(main):258:1>   }.run(Conn)
=> {"company"=>"Starfleet", "company_id"=>"064058b6-cea9-4117-b92d-c911027a725a", "employees"=>[], "id"=>"064058b6-cea9-4117-b92d-c911027a725a", "name"=>"Jean-Luc Picard", "rank"=>"captain", "type"=>"paramilitary"}

确保在运行查询之前已创建所有适当的表和索引：

// Create the tables
r.table_create("companies").run(Conn)
r.table_create("employees").run(Conn)

// Create the index
r.table("employees").index_create("company_id").run(Conn)

// Insert a document
r.table("companies").insert({
    "id": "064058b6-cea9-4117-b92d-c911027a725a",
    "name": "Jean-Luc Picard",
    "company_id": "064058b6-cea9-4117-b92d-c911027a725a",
    "rank": "captain",
    "company": "Starfleet",
    "type": "paramilitary"
}).run(Conn)

RethinkDB子查询示例错误

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