Question

用于在logic.js中进行查询，我可以使用

await query('selectCommoditiesWithHighQuantity')

但是，如果我有多个输入，该怎么办？如果查询具有这样的功能

query selectCommoditiesByTimeAndOwnerAndDataType {
  description: "Select all commodities based on their sender country"
  statement:
      SELECT org.stock.mynetwork.Commodity
          WHERE(time  > _$from AND time < _$to AND owner == _$owner AND dataType == _$dataType)
}

如何从js端调用该查询？

编辑： js代码

/**
 * Track the trade of a commodity from one trader to another
 * @param {org.stock.mynetwork.Receive} receive - the receive to be processed
 * @transaction
 */
async function receiveCommodity(receive) {

    let q1 = await buildQuery('SELECT org.stock.mynetwork.Commodity ' +
                                                'WHERE (productName == _$productName AND owner == _$owner)');


let result2 = await query(q1,{productName:receive.productName,owner: receive.newOwner});
}

let result2 = await query(q1,{productName:receive.productName,owner: receive.newOwner});部分存在问题。如果我只使用productName: receive.productName，则效果很好，但是当我添加owner: receive.newOwner时，它需要serialize.json

Answer 1

因此，您可以在.qry文件内编写查询并调用它，但是我不建议这样做。您可以直接从SDK和logic.js文件中进行相同的查询。这样做的理由是，例如几天后，您想要添加一个按一定值查询的新API，如果您依靠.qry文件（将起作用），则需要部署一个新API。版本的智能联系人，而如果使用SDK，则可以更改API并尽快部署新的应用服务器。

async function someTransaction(receive) {
  let assetRegistry = await getAssetRegistry('YOUR_NAME_SPACE');
  let ownerRegistry = await getParticipantRegistry('YOUR_NAME_SPACE');

  let statement = 'SELECT NAME_SPACE_OF_ASSET WHERE (owner == _$owner && dataType == _$dataType)';
  let qry = buildQuery(statement);

  // This query can be done in different ways
  // assuming newOwner is a string (id of participant)
  let allAssets = await query(qry, { owner: receive.newOwner, dataType: receive.dataType });

  // assuming newOwner is a participant
  let allAssets = await query(qry, { owner: receive.newOwner.getIdentifier(), dataType: receive.dataType });

  if (allAssets.length === 0) {
    // No assets exists, add one
    // use assetRegistry.add()
  } else {
    for (var i = 0; i < allAssets.length; i++) {
      // Iterate over assets belonging to an owner of a product type
      // Do whatever here
      // use assetRegistry.update()
    };
  };

};

如果查询具有多个输入，如何在Hyperledger composer logic.js中使用查询？

1 个答案: