我正在使用node.js和puppeteer来获取一些数据。...现在我想使用mysql将获取的数据插入数据库中。下面的方法似乎起作用了……但令我困惑的是，在console.log（'DB插入成功。记录：'+ i）; 总是在后面，一段时间后它会停止...尽管仍然有带有记录的表。
那是我的应用程序：
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);
}
});
}
我可以在控制台中看到：
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
我想念什么？我想我需要将连接查询放在async.function中？！就像这里：在数据库中的循环中插入值（问题）：插入相同的值-节点js / sql。
只要保证connection.query正确即可await。您发布的其他问题的链接与您的问题非常相似。
反复问这个问题，因为它很难理解，但基本上connection.query是立即运行，跳到下一行，然后再过一段时间（当数据库响应并且事件循环有时间来处理它时），function(err, rows) {}零件开始运行。因此，在您的某些pepeteer等待（或其他异步进程）之间，它正在处理function(err,rows){}。
下一条建议：学会使用util.promisify！（https://nodejs.org/dist/latest-v8.x/docs/api/util.html#util_util_promisify_original）
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 (?,?)";
let rows = await new Promise((resolve,reject)=>{
connection.query(insertCompanyList,[tableCell02Val, tableCell01Val],function(err, rows) {
if (err) {
console.log(err);
reject(err);
} else {
console.log('DB insert successful. Record: '+i);
resolve(rows);
}
});
});
}
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