创建列类型为 RECORD 的 table

Question

我正在使用大查询，我想创建一个作业，用 "record" 类型的列填充 table。数据将由查询填充 - 那么我如何编写 returns "record" 类型列的查询。

谢谢！

Answer 1

您需要使用 dot 符号将输出反映为 RECORD 示例查询：

select 
  'florida' as country.state, 
  'SFO' as country.city;

在此示例中，country 是记录，state|city 是记录中的字段。

Answer 2

不知何故，Pentium10 提出的选项在 GBQ UI 或 API Explorer 中对我不起作用。
我可能遗漏了什么

同时，我找到的解决方法如下例所示

SELECT location.state, location.city FROM JS(
  (      // input table
  SELECT NEST(CONCAT(state, ',', city)) AS locations
  FROM (
    SELECT state, city FROM 
    (SELECT 'florida' AS state, 'miami' AS city),
    (SELECT 'california' AS state, 'la' AS city),
    (SELECT 'romania' AS state, 'transylvania' AS city)
    ) 
  ),
  locations,     // input columns
  "[    // output schema
    {'name': 'location', 'type': 'RECORD',
     'mode': 'REPEATED',
     'fields': [
       {'name': 'state', 'type': 'STRING'},
       {'name': 'city', 'type': 'STRING'}
     ]    
    }
  ]",
  "function(row, emit){    // function 
    for (var i = 0; i < row.locations.length; i++) {
      var c = [];
      x = row.locations[i].split(',');
      t = {state:x[0], city:x[1]}
      c.push(t);
      emit({location: c});  
    };
  }"
)

请注意：
您应该将目标 table 设置为 Allow Large Results 并取消选中 Flatten Results

输出 table 的结果是（在 JSON 模式下）

[
  {
    "location": [
      {
        "state": "california",
        "city": "la"
      }
    ]
  },
  {
    "location": [
      {
        "state": "florida",
        "city": "miami"
      }
    ]
  },
  {
    "location": [
      {
        "state": "romania",
        "city": "transylvania"
      }
    ]
  }
]

Added to address some issue @AdiCohen has with his real example that he showed in his recent comments:

Q: my query has other columns besides the record column, but when i ran the query, they return as null. how can i create a table with both of the types?

SELECT amount, currency, location.state, location.city FROM JS( 
  ( // input table 
    SELECT NEST(CONCAT(state, ',', city)) AS locations, 
      SUM(amount) AS amount, MAX(currency) as currency 
    FROM ( 
      SELECT state, city, amount, currency, ROW_NUMBER() OVER() as grp FROM 
        (SELECT 'florida' AS state, 'miami' AS city, 'coins' AS currency, 40 AS amount), 
        (SELECT 'california' AS state, 'la' AS city, 'coins' AS currency, 40 AS amount), 
        (SELECT 'romania' AS state, 'transylvania' AS city,'coins' AS currency, 40 AS amount) 
    ) GROUP BY grp
  ), 
  amount, currency, locations, // input columns 
  "[ // output schema 
    {'name': 'location', 'type': 'RECORD', 'mode': 'REPEATED', 
    'fields': [ 
      {'name': 'state', 'type': 'STRING'}, 
      {'name': 'city', 'type': 'STRING'} 
    ] }, 
    { 'name': 'amount', 'type': 'INTEGER'}, 
    { 'name': 'currency', 'type': 'STRING'} 
  ]", 
  "function(row, emit) { // function 
    for (var i = 0; i < row.locations.length; i++) { 
      var c = []; 
      x = row.locations[i].split(','); 
      t = {state:x[0], city:x[1]} 
      c.push(t); 
      emit({amount: row.amount, currency: row.currency, location: c}); 
    }; 
  }"
)

这里的输出是：

[
  {
    "amount": "40",
    "currency": "coins",
    "location_state": "romania",
    "location_city": "transylvania"
  },
  {
    "amount": "40",
    "currency": "coins",
    "location_state": "florida",
    "location_city": "miami"
  },
  {
    "amount": "40",
    "currency": "coins",
    "location_state": "california",
    "location_city": "la"
  }
]

创建列类型为 RECORD 的 table

create a table with a column type RECORD

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