join - 如何将 POLYGON 的字符串类型转换为地理类型 - BigQuery

Question

我正在尝试将 STRING 数据类型转换为 GEOGRAPHY 重复类型，以便连接 Bigquery 中的两个表。我对 Bigquery 不太熟悉，因此我们将不胜感激。

我的第一个表称为 DealerInfo，具有以下数据类型:

1. 经销商 ID - STRING
2. 地理 - 地理

我的第二个表称为“城市”:

1. 城市名称 - STRING
2. 几何 - STRING

几何字符串看起来像这样:

POLYGON ((-28.855180740356388 -20.470634460449162,-28.855382919311467
          -20.470634460449162,-28.855499267578125 -20.470554351806527,
          -28.855585098266545 -20.470428466796818,-28.855623245239258
          -20.470342636108398,-28.855686187744141 -20.470207214355469,
          -28.855756759643498 -20.470096588134766,-28.855855941772404
          -20.470016479492188,-28.856058120727482 -20.469953536987305,
          -28.856224060058594 -20.469875335693303,-28.856462478637695
          -20.469699859619141,-28.856561660766602 -20.46949577331543,
          -28.856527328491154 -20.469383239746037,-28.856527328491154
          -20.469097137451115,-28.856479644775334 -20.468908309936523,
          -28.856412887573185 -20.468816757202148,-28.856327056884766
          -20.468719482421818,-28.856176376342773 -20.468656539916935,
          -28.855871200561467 -20.46859169006342,-28.855756759643498
          -20.46859169006342,-28.855636596679574 -20.468561172485295,
          -28.855499267578125 -20.468547821044808,-28.855382919311467
          -20.468450546264648,-28.855401992797852 -20.468360900878793,
          -28.855417251586914 -20.468278884887638,-28.8554668426513…

虽然 Geographies 变量看起来完全相同，但它是 GEOGRAPHY 数据类型，因此我无法连接表。

任何建议/代码将不胜感激!

这是我用来尝试将 STRING 转换为 GEOGRAPHY 以连接两个表的代码:

SELECT 
    ST_MAKEPOLYGON(geometry) AS NEW_GEO
FROM `DWH.CASE1.BrazilCitiesGeographies` 
LIMIT 1000 

Answer 1

要将 POLYGON 的字符串类型转换为 BigQuery Geography 类型，您应该使用 ST_GEOGFROMTEXT() 函数，如下例所示

SELECT 
    ST_GEOGFROMTEXT(geometry) AS NEW_GEO
FROM `DWH.CASE1.BrazilCitiesGeographies` 
LIMIT 1000