问题
I am building a Google App Maker application that takes a user-uploaded Excel CSV spreadsheet file as input. I have thought of multiple, possible solutions to reading the data from this file, but I have encountered this error: "Exception: FILENAME.csv exceeds the maximum file size" each time. I have tried extracting the data via parseCSV() to Google Cloud SQL, reading in as one string via .getBlob().getDataAsString() and splitting it by "\n," and writing all the data to Google Docs and trying to read it from there. However, all of these methods have resulted in the same error.
Is there any workaround solution to solving this maximum file size problem?
I have thought of splitting the file into smaller CSV files, but I am unsure of how to do this.
回答1:
You want to convert the large CSV file to the split Spreadsheet. If my understanding is correct, how about this workaround?
Issues and workarounds for this situation :
When such large CSV file is converted to Spreadsheet, it cannot directly convert to Spreadsheet, because of both the total number of cells and the size of file. And also when the large file is tried to split, it cannot do it because the blob which can be used at GAS is less than 50 MB (52,428,800 bytes).
- In order to split such large file, it uses "Partial download" of files.get in Drive API.
In my environment, when a CSV file with the size of 100 MB is used for this sample script, when the file is split by 10 MB, about 65 seconds was required to convert a chunk to Spreadsheet. In this case, when the CSV file is completely converted, it is considered that it will be over the limitation time (6 min) for executing GAS.
- In order to avoid this, it is required to implement the resumable conversion from the large CSV-file to several spreadsheets.
Prepare :
In order to use this sample script, please enable Drive API at Advanced Google Services and API console.
Enable Drive API v2 at Advanced Google Services
- On script editor
- Resources -> Advanced Google Services
- Turn on Drive API v2
Enable Drive API at API console
- On script editor
- Resources -> Cloud Platform project
- View API console
- At Getting started, click Enable APIs and get credentials like keys.
- At left side, click Library.
- At Search for APIs & services, input "Drive". And click Drive API.
- Click Enable button.
- If API has already been enabled, please don't turn off.
Sample script :
function createSplitSpreadsheet(obj) {
var accessToken = ScriptApp.getOAuthToken();
var baseUrl = "https://www.googleapis.com/drive/v3/files/";
// Retrieve file size.
var url1 = baseUrl + obj.fileId + "?fields=size";
var params1 = {
method: "get",
headers: {Authorization: "Bearer " + accessToken},
};
var fileSize = Number(JSON.parse(UrlFetchApp.fetch(url1, {headers: {Authorization: "Bearer " + accessToken}}).getContentText()).size);
// Calculate number of output files.
if (obj.files == null) {
obj.number = 1;
obj.start = 0;
}
var start = obj.start;
var end = start + obj.chunk;
var useFileSize = fileSize - start;
f = Math.floor(useFileSize / obj.chunk);
f = useFileSize % obj.chunk > 0 ? f + 1 : f;
if (f < obj.files || obj.files == null) {
obj.files = f;
}
// Split large file by chunk size (bytes).
var url2 = baseUrl + obj.fileId + "?alt=media";
var i;
for (i = 0; i < obj.files; i++) {
var params = {
method: "get",
headers: {
Authorization: "Bearer " + accessToken,
Range: "bytes=" + start + "-" + end,
},
};
var res = UrlFetchApp.fetch(url2, params).getContentText();
var e = res.lastIndexOf("\n");
start += e + 1;
end = start + obj.chunk;
Drive.Files.insert(
{mimeType: MimeType.GOOGLE_SHEETS, title: obj.fileName + (i + obj.number)},
Utilities.newBlob(res.substr(0, e), MimeType.CSV)
);
}
// Return next start value if there is a next chunk for the resume.
if (start < fileSize) {
return {nextStart: start, nextNumber: i + obj.number};
} else {
return null;
}
}
// Please run this function.
function main() {
var obj = {
fileId: "#####", // File ID of the large CSV file.
chunk: 10485760, // 10MB Please modify this for your situation.
files: 3, // Please input the number of files you want to convert.
start: 0,
fileName: "sample",
number: 1, // Counter of output files. Please input this as a next number.
};
var nextStart = createSplitSpreadsheet(obj);
Logger.log(nextStart);
}
Usage :
When you use this, please modify obj in main() for your situation, and run main(). A sample case is as follows.
It supposes as follows.
- You want to convert the CSV file with the size of 100 MB to 10 spreadsheets.
- Size of one chunk is 10 MB.
- CSV file is processed by every 3.
In this sample case, each obj is as follows. Please input each obj at each run.
var obj = {fileId: "#####", chunk: 10485760, files: 3, start: 0, fileName: "sample", number: 1}{"nextStart": ### nextStart2 ###, "nextNumber": 4}is returned fromcreateSplitSpreadsheet().
var obj = {fileId: "#####", chunk: 10485760, files: 3, start: ### nextStart2 ###, fileName: "sample", number: 4}{"nextStart": ### nextStart3 ###, "nextNumber": 7}is returned fromcreateSplitSpreadsheet().
var obj = {fileId: "#####", chunk: 10485760, files: 3, start: ### nextStart3 ###, fileName: "sample", number: 7}{"nextStart": ### nextStart4 ###, "nextNumber": 10}is returned fromcreateSplitSpreadsheet().
var obj = {fileId: "#####", chunk: 10485760, files: 3, start: ### nextStart4 ###, fileName: "sample", number: 10}nullis returned fromcreateSplitSpreadsheet().
By this flow, 10 spreadsheets are created from the CSV file with the size of 100 MB.
If null is used for files in obj, files is automatically calculated. But in this case, the limitation time for executing GAS may be over. Please be careful this.
References :
- Partial download
- Advanced Google Services
- Drive API
If this was not what you want, I'm sorry.
来源：https://stackoverflow.com/questions/51032451/workaround-solutions-to-google-app-script-exception-filename-csv-exceeds-the-m