Append 最后一个空行上的新记录（而不是忽略最后一个空行并在工作表末尾添加新行）

Question

I have this script it works ok. But, it ignores the blank rows after the last record row in the sheet. Instead it adds a whole new row to the end of the sheet for the new record that is being appended. For example: I have a sheet with 1000 rows. At this instance, there are only records up to row 25. So, what it does... it adds/ appends the new record at row 1001 instead of adding it to the empty row after the last record ie row 26.

Here is a dummy sheet link: https://docs.google.com/spreadsheets/d/1mt9G9PWdIvAQsQSWmRb14o8eeocCx9gkOWJT6KHAGa0/edit?usp=sharing

function appendUniqueRows() {
      var ss = SpreadsheetApp.getActive();
      var sourceSheet = ss.getSheetByName('source');
      var destSheet = ss.getSheetByName('destination');
    
      var sourceData = sourceSheet.getRange("A:D").getValues();
      var destData = destSheet.getRange("E:H").getValues();
    
      //Check whether destination sheet is empty
    if (destData.length === 1 && "" === destData[0].join('')) {
      // Empty, so ignore the phantom row
        destData = [];
      }
    
      // Generate hash for comparisons
      var destHash = {};
      destData.forEach(function(row) {
        destHash[row.join('')] = true; // could be anything
      });
    
      // Concatentate source rows to dest rows if they satisfy a uniqueness filter
      var mergedData = destData.concat(sourceData.filter(function (row) {
        var hashedRow = row.join('');
        if (!destHash.hasOwnProperty(hashedRow)) {
          // This row is unique
          destHash[hashedRow] = true;   // Add to hash for future comparisons
          return true;                  // filter -> true
        }
        return false;                   // not unique, filter -> false
      }));
    
      // // Check whether two data sets were the same width
      // var sourceWidth = (sourceData.length > 0) ? sourceData[0].length : 0;
      // var destWidth = (destData.length > 0) ? destData[0].length : 0;
      // if (sourceWidth !== destWidth) {
      //   // Pad out all columns for the new row
      //   var mergedWidth = Math.max(sourceWidth,destWidth);
      //   for (var row=0; row<mergedData.length; row++) {
      //     for (var col=mergedData[row].length; col<mergedWidth; col++)
      //       mergedData[row].push('');
      //   }
      // }
    
      // Write merged data to destination sheet
      destSheet.getRange(1, 5, mergedData.length, mergedData[0].length)
               .setValues(mergedData);
    }

Answer 1

I believe your goal as follows.

• You want to add the filtered sourceData to the next row of the last row of destData .

I think that the reason of your issue is due to var mergedData = destData.concat(sourceData.filter(function (row) { . In this case, the filtered sourceData is added to destData of var destData = destSheet.getRange("E:H").getValues(); . destSheet.getRange("E:H").getValues() includes the empty rows. So, in this case, how about the following modification?

From:

var sourceData = sourceSheet.getRange("A:D").getValues();
var destData = destSheet.getRange("E:H").getValues();

To:

var sourceData = sourceSheet.getRange("A1:D" + sourceSheet.getLastRow()).getValues();
var destData = destSheet.getRange("E1:H" + destSheet.getLastRow()).getValues();

or

From:

var mergedData = destData.concat(sourceData.filter(function (row) {

To:

var mergedData = destData.filter(row => row.join('')).concat(sourceData.filter(function (row) {

Note:

• When the process cost is considered, I think that the 1st modification will be suitable.