Question

我是node.js的新手。我已成功连接MySQL数据库。我可以做简单的选择查询，但是当我尝试使用多个JOIN的查询时，它会在参数列表

之后向我抛出错误，说明缺失
app.get('/quotes', function (req, res) { mc.query(`SELECT p.sku,pa.attribute_value as is_seen, pa1.attribute_value as rating,m.projects_unit_id as project_id,m.version,sp.total_sale_price as total_price, p.published_on,im.image_url as image, im1.image_url as pdf_link FROM my_designs m INNER JOIN product p on m.sku=p.sku and p.is_deleted=0 and p.is_published=1 INNER JOIN supplier_product sp on sp.product_id=p.product_id and sp.is_deleted=0 LEFT JOIN images im on im.`key`=m.sku and im.image_type=36 and im.is_deleted=0 LEFT JOIN images im1 on im1.`key` = m.sku and im1.image_type = 15 and im1.is_deleted=0 LEFT JOIN product_attributes pa on pa.common_id = p.sku and pa.is_deleted = 0 and pa.attribute_name = 'is_seen' LEFT JOIN product_attributes pa1 on pa1.common_id = p.sku and pa1.is_deleted = 0 and pa1.attribute_name = 'rating' WHERE m.user_id=? and m.is_deleted=0 and m.projects_unit_id is not null ORDER BY p.published_on DESC`, function (error, results, fields) { if (error) throw error; return res.send({ error: false, data: JSON.stringify(results), message: 'quote list.' }); }); });

请告诉我哪里出错了。

Answer 1

由于您使用的是模板文字

模板文字由back-tick (``)（重音符号）括起来字符而不是双引号或单引号。
模板文字可以包含占位符。这些都表示为美元符号和花括号(${expression})。

Here is the documentation

因此，您必须使用 im.${key}

而不是 im .key`

所以，你的代码变成了，

app.get('/quotes', function (req, res) {

mc.query(`SELECT p.sku,pa.attribute_value as is_seen, pa1.attribute_value as rating,m.projects_unit_id as project_id,m.version,sp.total_sale_price as total_price,
    p.published_on,im.image_url as image, im1.image_url as  pdf_link FROM my_designs m INNER JOIN product p on m.sku=p.sku and p.is_deleted=0 and p.is_published=1 
    INNER JOIN supplier_product sp on sp.product_id=p.product_id and sp.is_deleted=0 
    LEFT JOIN images im on im.${key}=m.sku and im.image_type=36 and im.is_deleted=0 
    LEFT JOIN images im1 on im1.${key} = m.sku and im1.image_type = 15 and im1.is_deleted=0 
    LEFT JOIN product_attributes pa on pa.common_id = p.sku and pa.is_deleted = 0 and pa.attribute_name = 'is_seen' 
    LEFT JOIN product_attributes pa1 on pa1.common_id = p.sku and pa1.is_deleted = 0 and pa1.attribute_name = 'rating' 
    WHERE m.user_id=? and m.is_deleted=0 and m.projects_unit_id is not null ORDER BY p.published_on DESC`, function (error, results, fields) {
    if (error) throw error;
    return res.send({ error: false, data: JSON.stringify(results), message: 'Todos list.' });
    }
);

});

<强> PS：

由于您有其他人知道的原因，键是一个reserved字。

Answer 2

您正在尝试使用template literals。您需要在变量周围使用$，这就是编写查询所需的方法，

`Select * from Table where key = ${key} and otherkey = ${otherkey}`

在Mysql查询中的参数列表之后的SyntaxError：Missing）

2 个答案: