众所周知,我们可以通过表——>rowkey——>列族——>列名——>时间戳去定位一个数据,下面是用API对数据的删除
当我们想去删除整个一行数据时(rowkey相同的全部删除)
public class HbaseDMLTest {
private static Connection connection = null;
private static Admin admin = null;
static {
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","hdp-1,hdp-2,hdp-3");
try {
connection = ConnectionFactory.createConnection(configuration);
admin = connection.getAdmin();
} catch (IOException e) {
e.printStackTrace();
}
}
//删除指定rowkey的所有数据
public static void deleteRow(String tableName,String rowKey) throws IOException {
//获取表对象
Table table = connection.getTable(TableName.valueOf(tableName));
//构建Delete对象
Delete delete = new Delete(Bytes.toBytes(rowKey));
//删除操作
table.delete(delete);
//关闭资源
table.close();
}
public static void main(String[] args) throws IOException {
deleteRow("t2", "004");
}
}
这样我们就将表名为t2,rowkey为004的数据全部删除了
当我们想去删除某个列的数据时
public class HbaseDMLTest {
private static Connection connection = null;
private static Admin admin = null;
static {
Configuration configuration = HBaseConfiguration.create();
configuration.set("hbase.zookeeper.quorum","hdp-1,hdp-2,hdp-3");
try {
connection = ConnectionFactory.createConnection(configuration);
admin = connection.getAdmin();
} catch (IOException e) {
e.printStackTrace();
}
}
//删除指定列的数据
public static void deleteCN(String tableName,String rowKey,String cf,String cn) throws IOException{
Table table = connection.getTable(TableName.valueOf(tableName));
Delete delete = new Delete(Bytes.toBytes(rowKey));
//addColumn是删除最新版本的列的数据,也可以传入时间戳,会删除指定时间戳的那个版本数据
// delete.addColumn(Bytes.toBytes(cf),Bytes.toBytes(cn));
//addColumns是删除所有版本的列的数据,也可以传入时间戳,会将小于等于传入的时间戳的全部版本删除掉
delete.addColumns(Bytes.toBytes(cf),Bytes.toBytes(cn));
table.delete(delete);
table.close();
}
public static void main(String[] args) throws IOException {
deleteCN("t2", "001", "cf1", "age");
}
}
其中delete调用有两个方法,一个addColumns,一个addColumn,注意二者区别,当我们想删除所有版本时,就用addColumns,当我们想删除某个版本时,我们就用addColumn,记得后面传入时间戳