[英]BigQuery - Fetch table data from Go Server in Cloud Run
I am able to fetch the Big Query table output as json through Golang server.我能够通过 Golang 服务器获取大查询表 output 作为 json。 But is there a way to fetch the schema directly instead of defining it as ColStatsRow
?但是有没有办法直接获取模式而不是将其定义为ColStatsRow
? Also, any way to make this better.此外,任何使这更好的方法。
type ColStatsRow struct {
COLUMN_NAME string `bigquery:"column_name"`
COLUMN_VALUE string `bigquery:"column_value"`
FREQUENCY int64 `bigquery:"frequency"`
}
// getOutput prints results from a query
func getOutput(w http.ResponseWriter, iter *bigquery.RowIterator) error {
var rows []ColStatsRow
for {
var row ColStatsRow
err := iter.Next(&row)
if err == iterator.Done {
out, err := json.Marshal(rows)
if err != nil {
return fmt.Errorf("error marshalling results: %v", err)
}
w.Write([]byte(out))
return nil
}
if err != nil {
return fmt.Errorf("error iterating through results: %v", err)
}
rows = append(rows, row)
}
}
Thank you.谢谢你。
If you're after the schema for the result, it's available on the RowIterator
.如果您追求结果的架构,则可以在RowIterator
上使用它。
If you mean you want to more dynamically process the rows without a specific struct, usually some combination of checking the schema and/or leveraging a type switch is the way to go about this.如果您的意思是您想要更动态地处理没有特定结构的行,通常检查架构和/或利用类型开关的某种组合是 go 关于此的方法。
According to the documentation you can specify a JSON schema file
like this:根据文档,您可以像这样指定JSON schema file
:
[
{
"description": "[DESCRIPTION]",
"name": "[NAME]",
"type": "[TYPE]",
"mode": "[MODE]"
},
{
"description": "[DESCRIPTION]",
"name": "[NAME]",
"type": "[TYPE]",
"mode": "[MODE]"
}
]
and then you can write this schema using the following command:然后您可以使用以下命令编写此架构:
bq show --schema --format=prettyjson project_id:dataset.table > path_to_file
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