我正在使用node.js和puppeter获取一些数据。。。现在我想把提取的数据插入数据库。。。使用mysql。下面的方法似乎有效。。。然而让我困惑的是，在console.log（'db insert successful。记录：'+i）；总是落后，过了一段时间就停了。。。尽管仍有记录可用的表。
这是我的应用程序：
let tableCell01;
let tableCell01Val;
let tableCell02;
let tableCell02Val;
const tableRows = await page.$$('table.tableFile2 > tbody > tr');
for (let i=1; i < tableRows.length; i++){
tableRow = tableRows[i];
tableCell01 = await tableRow.$('td:nth-child(1) a');
tableCell01Val = await page.evaluate( tableCell01 => tableCell01.innerText, tableCell01 );
tableCell02 = await tableRow.$('td:nth-child(2)');
tableCell02Val = await page.evaluate( tableCell02 => tableCell02.innerText, tableCell02 );
tableCell02ValA.replace(/(^\s+|\s+$)/g,'');
console.log('\n');
console.log('ID: '+tableCell01Val);
console.log('Company: '+tableCell02Val);
console.log('Iterator: '+i);
const insertCompanyList = "INSERT INTO companyList ( company_name, id ) values (?,?)";
connection.query(insertCompanyList,[tableCell02Val, tableCell01Val],function(err, rows) {
if (err) {
console.log(err);
} else {
console.log('DB insert successful. Record: '+i);
}
});
}我可以在控制台看到：
ID: 3136
Company: Company A
Iterator: 1
ID: 3143
Company: Company B
Iterator: 2
DB insert successful. Record: 1
ID: 4497
Company: Company C
Iterator: 3
ID: 3164
Company: Company D
Iterator: 4
ID: 3219
Company: Company E
Iterator: 5
ID: 3071
Company: Company F
Iterator: 6
ID: 3184
Company: Company G
Iterator: 7
DB insert successful. Record: 2
ID: 3130
Company: Company H
Iterator: 8
DB insert successful. Record: 3
DB insert successful. Record: 4
DB insert successful. Record: 5
DB insert successful. Record: 6
DB insert successful. Record: 7
DB insert successful. Record: 8
ID: 1844
Company: Company I
Iterator: 1
ID: 3687
Company: Company J
Iterator: 2
ID: 4514
Company: ECompany K
Iterator: 3
ID: 3635
Company: Company L
Iterator: 4
ID: 3884
Company: Company M
Iterator: 5
ID: 3482
Company: Company N
Iterator: 6
DB insert successful. Record: 1
ID: 3482
Company: Company O
Iterator: 7
ID: 1827
Company: Company P
Iterator: 8
DB insert successful. Record: 2
ID: 1827
Company: Company Q
Iterator: 9
ID: 6465
Company: Company R
Iterator: 10
ID: 0731
Company: Company S
Country: B9
Iterator: 11
No pagination!
DB insert successful. Record: 3
DB insert successful. Record: 4
DB insert successful. Record: 5
DB insert successful. Record: 6
DB insert successful. Record: 7
DB insert successful. Record: 8
DB insert successful. Record: 9
DB insert successful. Record: 10
DB insert successful. Record: 11我错过了什么？我想我需要把连接查询放在一个异步函数里？！像这样：在数据库中的循环（for）中插入值：插入相同的值-节点js/sql。？
1条答案
按热度按时间svmlkihl1#
只需promisify connection.query就可以了
await是的。你发布的另一个问题的链接与你的问题非常相似。这个问题被反复问，因为很难理解，但基本上
connection.query立即运行，跳到下一行，然后在稍后某个时间点（当数据库响应并且事件循环有时间处理它时）运行function(err, rows) {}零件运行。因此，在一些pupeter等待（或其他异步进程）之间，它正在处理function(err,rows){}.下一个建议：学会使用
util.promisify! (https://nodejs.org/dist/latest-v8.x/docs/api/util.html#util_util_promisify_original)