mysql - 循环查询在 Node js 中 Sequelize

Question

我有一个循环，我正在检查记录是否存在，如果没有插入，问题是我的控制台显示循环内的代码没有逐行运行，它首先运行所有选择，然后运行所有插入
从excel循环

tablesdata.map(async function (table) {   
    check if record exist
          await product_meta
                .count({
                  where: [
                    {
                      title: fr_name,
                      language_id: 2,
                    },
                  ],
                })
                .then((count) => {
                  console.log(count);
                  if (count > 0) {
                    console.log(count);
                  } else {
                    insert record create_pr = products.create(product, {});product_id = create_pr.id;
                  }
                  
        )}
 )}

Answer 1

使用 async/await 会更直接 - Array.map() 返回一个可以使用 Promise.all() 解析的 promise 数组。

const promises = tablesdata.map(async function (table) {
  if (recordExists) {
    const count = await product_meta.count({
      where: {
        title: fr_name,
        language_id: 2,
      },
    });

    if (!count) {
      // this will create a new product, perhaps it is meant to be a product meta?
      const create_pr = await products.create(product, {});
      // return the created ID
      return create_pr.id;
    }
    
    console.log("there are already", count, "product metas");
    return null;
  }
});

// this will resolve an array of newly created IDs,
const allResults = await Promise.all(promises);
// filter out the null entries
const productIds = allResults.filter((result) => result);