通过java编码更新/替换googlebigquery中的表数据

Question

我正在尝试使用java更新bigquery表数据。根据我的研究，WriteDisposition是一个选项。我有点新手，过不去。好心帮忙。

也就是说，我尝试过使用WriteChannelConfiguration插入，效果很好。需要对此代码进行更改才能更新表。

public class BigQryAPI {
public static void explicit() {
// Load credentials from JSON key file. If you can't set the GOOGLE_APPLICATION_CREDENTIALS
// environment variable, you can explicitly load the credentials file to construct the
// credentials.
try {
GoogleCredentials credentials;
File credentialsPath = new File(BigQryAPI.class.getResource("/firstprojectkey.json").getPath());  // TODO: update to your key path.
FileInputStream serviceAccountStream = new FileInputStream(credentialsPath);
credentials = ServiceAccountCredentials.fromStream(serviceAccountStream);
// Instantiate a client
BigQuery bigquery =
BigQueryOptions.newBuilder().setCredentials(credentials).build().getService();
System.out.println("Datasets:");
for (Dataset dataset : bigquery.listDatasets().iterateAll()) {
System.out.printf("%s%n", dataset.getDatasetId().getDataset());
}

//load into table

TableId tableId = TableId.of("firstdataset","firsttable");

WriteChannelConfiguration writeChannelConfiguration =
WriteChannelConfiguration.newBuilder(tableId).setFormatOptions(FormatOptions.csv()).build();
TableDataWriteChannel writer = bigquery.writer(writeChannelConfiguration);
String csvdata="zzzxyz,zzzxyz";
// Write data to writer
try {
writer.write(ByteBuffer.wrap(csvdata.getBytes(Charsets.UTF_8)));
} finally {
writer.close();
}
// Get load job
Job job = writer.getJob();
job = job.waitFor();
LoadStatistics stats = job.getStatistics();
System.out.printf("these are my stats"+stats);
String query = "SELECT Name,Phone FROM `firstproject-256319.firstdataset.firsttable`;";
QueryJobConfiguration queryConfig = QueryJobConfiguration.newBuilder(query).build();
// Print the results.
for (FieldValueList row : bigquery.query(queryConfig).iterateAll()) {
for (FieldValue val :  row) {
System.out.printf("%s,", val.toString());
}
System.out.printf("n");
}
}catch(Exception e) {System.out.println(e.getMessage());}
}
}

Answer 1

我们可以在构建"WriteChannelConfiguration"时设置写解压缩

WriteChannelConfiguration writeChannelConfiguration = WriteChannelConfiguration.newBuilder(table.tableId).setFormatOptions(FormatOptions.csv())
.setWriteDisposition(JobInfo.WriteDisposition.WRITE_TRUNCATE).build()

详细信息可以在这里找到BigQuery API文档