传递参数时调用了错误的命名查询 Node.js

Question

我刚开始使用 Node.js、PostgresSQL 和 pg-promise，在我的 API 的获取端点中，我检查存在哪些参数，如果 city, region, country 是present 我调用 'get-city-products' 查询，如果存在 region, country 我调用 'get-region-products'，如果存在 country 我调用 'get-country-products'。当我只通过 region, country 或 country 它调用 'get-city-products'，没有 city 或 city, region 失败并且 return 没有产品.. 为什么缺少 city 参数时 else if (city, region, country) 会成功？你能发现我的业务逻辑有什么问题吗？这是固有代码：

// city
  else if (city, region, country) {
    await db.any({
      name: 'get-city-products',
      text: 'SELECT * FROM products WHERE city =  AND region =  AND country = ',
      values: [city, region, country]
    })
      .then(result => {
        console.log('get-city-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-city-products error:', error);
      });
  }

  // region => never gets called
  else if (region, country) {
    await db.any({
      name: 'get-region-products',
      text: 'SELECT * FROM products WHERE region =  AND country = ',
      values: [region, country]
    })
      .then(result => {
        console.log('get-region-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-region-products error:', error);
      });
  }

  // country => never gets called
  else if (country) {
    await db.any({
      name: 'get-country-products',
      text: 'SELECT * FROM products WHERE country = ',
      values: [country]
    })
      .then(result => {
        console.log('get-country-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-country-products error:', error);
      });
  }

这里是完整的方法：

exports.findProducts = async (req, res) => {

  // customers queries

  // sorted
  if (city, region, country, category, minPrice, maxPrice, orderedBy, sorted) {

    /// this will create a unique PreparedStatement name for each query type
    const name = 'getCityCategoryPriceRangeOrderedBy' + orderedBy + '' + sorted + ' Products';

    const text = pgp.as.format(`SELECT * FROM products WHERE city = $/city/
                            AND region = $/region/ AND country = $/country/
                            AND category = $/category/
                            AND price BETWEEN $/minPrice/ AND $/maxPrice/
                            ORDER BY $/orderedBy:name/ $/sorted:value/`, {
      city, region, country, category,
      minPrice, maxPrice, orderedBy, sorted
    });

    console.log('query for ' + name + ' is: ', text,);

    await db.any({ name: name, text: text })
      .then(result => {
        console.log(name + ' results: ', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log(name + ` error:`, error);
      });

  }


  // price range
  else if (city, region, country, category, minPrice, maxPrice) {
    await db.any({
      name: 'get-city-category-price-range-products',
      text: 'SELECT * FROM products WHERE city =  AND region =  AND country =  AND category =  AND price BETWEEN  AND ',
      values: [city, region, country, category, minPrice, maxPrice]
    })
      .then(result => {
        console.log('get-city-category-price-range-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-city-category-price-range-products error:', error);
      });
  }

  // city category
  else if (city, region, country, category) {
    await db.any({
      name: 'get-city-category-products',
      text: 'SELECT * FROM products WHERE city =  AND region =  AND country =  AND category = ',
      values: [city, region, country, category]
    })
      .then(result => {
        console.log('get-city-category-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-city-category-products error:', error);
      });
  }


  // city
  else if (city, region, country) {
    await db.any({
      name: 'get-city-products',
      text: 'SELECT * FROM products WHERE city =  AND region =  AND country = ',
      values: [city, region, country]
    })
      .then(result => {
        console.log('get-city-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-city-products error:', error);
      });
  }

  // region => never gets called
  else if (region, country) {
    await db.any({
      name: 'get-region-products',
      text: 'SELECT * FROM products WHERE region =  AND country = ',
      values: [region, country]
    })
      .then(result => {
        console.log('get-region-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-region-products error:', error);
      });
  }

  // country => never gets called
  else if (country) {
    await db.any({
      name: 'get-country-products',
      text: 'SELECT * FROM products WHERE country = ',
      values: [country]
    })
      .then(result => {
        console.log('get-country-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-country-products error:', error);
      });
  }


// shops queries

  else if (vendor) {
    await db.any({
      name: 'get-vendor-products',
      text: 'SELECT * FROM products WHERE vendor = ',
      values: [vendor]
    })
      .then(result => {
        console.log('get-vendor-products:', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found.'
          });
        }
      })
      .catch(function (error) {
        console.log('get-vendor-products error:', error);
      });
  }



  else {
    db.any({
      name: 'get-all-products',
      text: 'SELECT * FROM products ORDER BY id ASC',
    })
      .then(result => {
        console.log('get-all-products', result);
        if (result.length > 0) {
          res.status(200).send({
            data: result
          });
        }
        else {
          res.status(404).send({
            error: 'No product found'
          });
        }
      })
      .catch(function (error) {
        console.log('get-cityProducts error:', error);
      });
  }
};

我应该只为每个查询使用 1 个参数吗？

Answer 1

在您的条件子句（else ifs）中，您使用逗号分隔不同的值

else if (city, region, country) {

虽然语法并非完全无效（仅使用最终变量的值），但您可能正在寻找布尔比较

else if (city && region && country)

如果所有变量都为真，则执行条件。

传递参数时调用了错误的命名查询 Node.js

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