sqoop import --connect jdbc:mysql://host:port/message
--username message --password message
--query "select 't0_'+ message_id as message_key, some_split_id, some_other_columns
from message_0 where message_id >30000 and message_id <= 31000 and $CONDITIONS"
--split-by some_split_id --hbase-row-key message_key
--hbase-table message --column-family cf1

public void set_message_key(String message_key) {
    this.message_key = "t0_" + message_key;
}
public MessageImporter with_message_key(String message_key) {
    this.message_key = "t0_" + message_key;
    return this;
}
...
public void readFields(DataInput __dataIn) throws IOException {
    if (__dataIn.readBoolean()) {
        this.message_key = null;
    } else {
        this.message_key = "t0_" + Text.readString(__dataIn);
    }
    ...
...
}
...
private void __loadFromFields(List<String> fields) {
    Iterator<String> __it = fields.listIterator();
    String __cur_str;
    __cur_str = __it.next();
    if (__cur_str.equals("null") || __cur_str.length() == 0) { this.message_key = null; } else {
    this.message_key = "t0_" + __cur_str;
    }
    ...
}
...
public void setField(String __fieldName, Object __fieldVal) {
    if ("message_key".equals(__fieldName)) {
        this.message_key = "t0_" + (String) __fieldVal;
    }
    ...
}

--jar-file someJar.jar --class-name com.foo.SomeImportClass