Question

我有一个Hbase表，其中所有行的特定列值为

901877853087813636      column=metadata:collection-id, timestamp=1514594631532, value=1007

现在如何将表中所有行的值从1007更改为100.

所有帮助都指向修改特定行。

请帮助我

Answer 1

使用SingleColumnValueFilter扫描表以获取值为的所有行 1007和你可以使用批量put为所有这些行添加新值（1008）。例如扫描过滤器像这样：

 SingleColumnValueFilter singleColumnValueFilter = new SingleColumnValueFilter("metadata".getBytes(),
               "collection-id".getBytes(),CompareOp.EQUAL,
               new BinaryComparator(Bytes.toBytes(1007)));

Answer 2

HBase支持仅基于rowKey更新记录。因此，我们必须获取所有必须更新的记录，并创建我们自己的批量放置来更新这些记录，如下所示。

UpdateAllRows [tableName] [columnQualifier] [columnFamily] [oldValue] [newValue]

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;

public class UpdateAllRows {

    private static Connection conn;
    public static Admin getConnection() throws IOException {
        if (conn == null) {
            conn = ConnectionFactory.createConnection(HBaseConfiguration.create());
        }
        return conn.getAdmin();
    }

    public static void main(String args[]) throws Exception {
        getConnection();
        updateTable(args[0], args[1], args[2], args[3], args[4]);
    }


    public static void updateTable(String tableName, String columnFamily, String columnQualifier, String oldValue, String newValue) throws Exception{
        Table table = conn.getTable(TableName.valueOf(tableName));
        ResultScanner rs = scan(tableName, columnFamily, columnQualifier);

        byte[] cfBytes = Bytes.toBytes(columnFamily);
        byte[] cqBytes = Bytes.toBytes(columnQualifier);
        byte[] oldvalBytes = Bytes.toBytes(oldValue);
        byte[] newvalBytes = Bytes.toBytes(newValue);

        Result res = null;
        List<Put> putList = new ArrayList<Put>();
        try {
            while ((res = rs.next()) != null) {
                if (Arrays.equals(res.getValue(cfBytes, cqBytes), oldvalBytes)){
                    Put p = new Put(res.getRow());
                    p.addColumn(cfBytes, cqBytes, newvalBytes);
                    putList.add(p);
                }
            }
        } finally {
            rs.close();
        }
        table.put(putList);
        table.close();
    }

    public static ResultScanner scan(String tableName, String columnFamily, String columnQualifier) throws IOException {
        Table table = conn.getTable(TableName.valueOf(tableName));
        return  table.getScanner(new Scan().addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes(columnQualifier)));
    }
}

更新HBase中整列的值

2 个答案: