public String toSQLString() {
    StringBuilder sqlBuilder = new StringBuilder();
    sqlBuilder.append("INTO ");
    for (int i = 0; i < intoItems.size(); i++) {
      sqlBuilder.append(intoItems.get(i).toSQLString());
      if (i < intoItems.size() - 1) {
        sqlBuilder.append(", ");
      }
    }
    return sqlBuilder.toString();
  }
This class maintains information of {@code INTO} clause.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/statement/component/IntoComponent.java