我写了一个代码来创建.csv文件，并希望读取它并使用node存储在数据库中。下面是源代码（我跟随YouTube视频）：

const fs = require(fs); 
 
(async () => {     
    const writeStream = fs.createWriteStream('out.csv'); 
    for(let i=0; i< 1e8; i++){         
        const over= writeStream.write(`${i},1\n`); 
        if(!over){             
            await new Promise((resolve) => writeStream.once('drain', resolve))
        } 
    }     
    writeStream.end(); 
})

然而我得到错误;#app crashed，Cannot access 'fs' before initialization.
有人能帮忙吗？我也不知道如何将数据保存到数据库中。我也写了readStream代码：

const fs = require(fs); 
 
(async () => {     
    const readStream = fs.createReadStream('out.csv'); 
    let sum=0; 
    let unprocessed=''; 
     readStream.on('data', (chunk) => {         
        let chunkString = unprocessed+ chunk.toString();         
        unprocessed=''; 
        let startIndex=0; 
         
        for(let ch=startIndex; ch< chunkString.length; ch++){ 
             
            if(chunkString[ch] === '\n'){ 
                const line= chunkString.slice(startIndex, ch),                 
                idx= line.indexOf(','),                 
                cost= line.slice(idx+1); 
                sum += parseFloat(cost);                 
                startIndex= ch+1; 
            } 
        } 
    })      
    
    if(chunkString[chunkString.length-1]!=='\n'){         
        unprocessed= chunkString.slice(startIndex); 
    } 
});  
readStream.on('end', ()=> {     
    console.log(`sum: ${sum}`) 
})