We Keep Coding

How to add multiple values in one query to a PostgreSQL array?

So if I have a Javascript array of strings, how do I append each element to a row in the Postgres text[] column? This is what I'm currently using, but it's not yielding the desired result (which is just making the text array in the column of {"1","2","3"}.
let addNumbers = 'UPDATE numTable SET column1 = array_append(columnName, ($1)) WHERE uid = ($2)'
let x = ["1","2","3"]
I'm querying to the db with
query(addNumbers, [x, uid]);
I've tried using array_append but this results in the column getting a value of
{"{\"1\",\"2\",\"3\"}"}
I'd prefer not to iterate and append each one individually because this'll obviously increase the number of database calls--any help is much appreciated!

Dynamically adding / removing columns

I use datatables 1.10 for a while now, and I have come to a point in my development where I have a table in my db that stores a json object. Furthermore that table also contains an attribute called groupName. As the name suggests, the entries of that table are "grouped" by that attribute, and in that group, the json object has the same attributes.
Here an example of how my database table looks like:
+---------------------------------------------------------------------------+
|id|groupname |json |
+---------------------------------------------------------------------------+
|01|group1 |{"key1":"value1","key2":"value2"} |
|02|group1 |{"key1":"foo","key2":"bar"} |
|03|group2 |{"kex1":"foo1","keyab":"bar2","key1":"foo"}|
+---------------------------------------------------------------------------+
My page that contains the datatabase, and also has a dropdown menu populated with the group names which filters the the datatable for the particular group. The jsonObject of that filtered group is being displayed as a raw json string.
What I'm trying to do now is to parse my jsonObject, get the keys and populate them in the datatable as columns. The values of the jsonObject are displayed in the columns accordingly.
Where or how do I reinitialize the datatable, providing it with the proper column names?

Can you please share some example of your JSON object.
Thanks!
Any ways what you can do is to to take the keys of the json object and put them into array then using loop you can make a string of columns. Then you can provide an id to of the table and append the string into the table.
let keys = Object.keys(YOUR_JSON_OBJECT);
let text = "";
for(let i =0;i<keys.length;i++){
text+= ["<tr>","<td>",YOUR_JSON_OBJECT.its_key,"</td>","</tr>"].join("");
}
$('table thead').html(text);
See if this works!

Why won't append row work with array?

I am trying to insert a row to the bottom of a sheet, but instead of my values I see text similar to what happens when you try to print an array in Java. I checked to see if the array is made correctly with logger and it has the values I want.
var name = e.range.getRow() + SpreadsheetApp.getActiveSpreadsheet().getName();
var array = e.range.getValues().concat(name);
Logger.log(array.toString());
masterSheet.appendRow(array);
array contains a timestamp, string1, string2, and finally the name I concatenated. Instead I get something like [Ljava.lang.Object;#7dch7145

This is because appendRow() is looking for array[] not array[][].
If you attempt to append:
var array = [[1,2,3],"some string"]
It will show up as the following as it is trying to get the entire contents of the first position of the array in a single cell. It does this by returning a string of the array object which turns out to be the native code identifier.
[Ljava.lang.Object;#32dba1e2 | some string
You can append the contents of array by appending its individual members such as
ss.appendRow(array[0])
Would append
1 | 2 | 3

It looks like a problem with your use of getValues() which returns a two-dimensional array and needs to be accessed as such.
GAS API Reference: getValues()
Return
Object[][] — a two-dimensional array of values
I believe this edit to setting your var array should do the trick, assuming your data range is for a single row (index 0 will be the first row, otherwise just change the index to the row you want):
var array = e.range.getValues()[0].concat(name);

How to delete selected checkbox rows in an Oracle APEX Classic Report using Ajax

Within Oracle APEX v4.2.2, I have a simple classic report that has as a first column, a checkbox f50 setup attached to the table's ID column, which will allow a user to check all or specific rows and remove these records from the report/table.
An example report might be something like:
ID Col2 Col3 Col4
----------------------------
1 10 20 30
2 5 8 9
3 92 88 12
4 1 2 44
5 95 77 88
The requirement I am after is that I want to perform this whole process of checking the IDs and the removal of these records done without having to submit the whole page but would like it done via an AJAX method using apex.process.server if possible.
UPDATE: Just a bit more background on this requirement based on the report I am attempting to hook this apex.process.server checkbox IDs, i.e.:
ID Report Column above within Report Attributes heading looks like this:
<input type="checkbox" label="Select Code" onclick="$f_CheckFirstColumn(this)" />
Drilling down into this ID column under HTML Expression is the following:
<input type="checkbox" #ID# value="#ID#" name="f50" id="f50_#ROWNUM#"/>
Region Source:
SELECT A.ID,
A.REQ_NO COL2,
A.CODE_ID||apex_item.hidden(20, A.CODE_ID)||apex_item.hidden(30, A.ID) COL3,
GROUP_VALUE COL4
FROM MY_TABLE A
WHERE A.REQ_NO = :REQ_NO
I believe inorder to have APEX store the values within the apex_application.g_f50.countarray of the IDs to be removed, the page needs to be submitted.
Using apex.process.server, can the ids, as they are checked, be passed as a JavaScript array to an on demand process that will then use these ids to perform the required delete operation?
How can I achieve the above via an AJAX means (no page refresh at all)?

Given this query for a report
select
"EMPNO",
"ENAME",
apex_item.checkbox2(2, 0) check1,
apex_item.checkbox2(3, 0) check2,
apex_item.checkbox2(4, 0) check3
from EMP
With EMPNO set to "Hidden" - so it'll generate a hidden input item appended to the last column.
To update a certain record you'll need a PK and a value to update the row with. That is why I'm using EMPNO. I'll pass that to the on-demand process.
function selectorToArray(pSelector){
function getVal(pNd){
switch ( pNd.nodeName ) {
case "INPUT":
switch ( pNd.type ) {
case "checkbox":
return $(pNd).prop("checked");
break;
default:
return $(pNd).val();
};
break;
default:
return $(pNd).val()
};
};
var lArray = [];
$(pSelector).each(function(){
lArray.push(getVal(this));
});
return lArray;
};
The function selectorToArray will fetch the values for the given selector to an array and get the value. As you might know, you can pass values to a process with x01, x02, ... But there are also arrays: f01, f02,...
With the following code you can send values over to the ondemand process:
function sendCheckboxes(){
var lf01 = [], lf02 = [], lf03 = [], lf04 = [];
lf01 = selectorToArray("input[name=f01]");
lf02 = selectorToArray("input[name=f02]");
lf03 = selectorToArray("input[name=f03]");
lf04 = selectorToArray("input[name=f04]");
apex.server.process("PROCESS_CHECKBOXES", {f01: lf01, f02: lf02, f03: lf03, f04: lf04});
};
You can use those just like you would otherwise: loop over them:
DECLARE
l_pk VARCHAR2(30);
l_check1 VARCHAR2(30);
l_check2 VARCHAR2(30);
l_check3 VARCHAR2(30);
BEGIN
-- f01: PK
-- f02: checkbox values column1
FOR i IN 1..apex_application.g_f01.count
LOOP
l_pk := apex_application.g_f01(i);
l_check1 := apex_application.g_f02(i);
l_check2 := apex_application.g_f03(i);
l_check3 := apex_application.g_f04(i);
apex_debug.message('Record with PK '||l_pk||': check1? '||NVL(l_check1, 'NO')||': check2? '||NVL(l_check2, 'NO')||': check3? '||NVL(l_check3, 'NO'));
END LOOP;
END;
In your code, there are 3 item arrays: f20, f30 and f50. f30 holds the row PK value, while f50 is used for the checkbox.
Don't be fooled by the array naming. Apex itself uses the f## arrays for submission, true enough. And your items with name f50 will indeed be in array g_f50 on page submit.
You can however also use arrays f01 to f20 (don't think it goes up to 50) for ajax calls! They're a great addition to the variables x01-x20!
When using the arrays to send a bulk of values to your process, instead of one-by-one, I think it's most useful to not just send an array of PK values, with a position-matched array of values to interact with. This isn't as valuable when you use a report without pagination though, but still. With pagination, the idea is that you don't really know what set of data was just interacted with. Of 100 records, 10 rows were presented. Of those 10 rows, 6 were checked on render, and on submit only 5 are. Which ones are checked and which ones are unchecked. Knowing which 5 are checked doesn't mean you know the unchecked ones.
When you include a PK column however, you'll always have those 10 rows and you're able to identify clearly which records has been checked or unchecked.
For instance, 10 records in your report will (=should!) mean that 10 values are put in an array (eg l_f01) with the PK value and 10 more values are put in another array (eg l_f02) with eg a checked indicator. So when passing those on to the on-demand process, you'll be able to loop over array f01 reliably, and fetch the checked or unchecked indicator from array f02 with your current index variable used for f01.
Plainly put, you're building up 2 arrays with this sort of value set:
f01 - IDs | f02 - checkeds
----------|---------------
4520 | false
4521 | true
4527 | false
4561 | true
4578 | true

Strategy to extract structured data with xpath

Is there a pattern to extract structured data from an HTML page using XPath? I'm trying to extract data from one or more HTML tables on a page. XPath makes it easy to find the table(s), but I'm struggling once I've got that far.
I'm currently doing the following:
Iterate the tables (there may be more than one)
Iterate the rows within that table
Iterate the cells within that row
(Then probably put them in an array and parse the contents)
My code is something like this:
var tables = mydoc.evaluate( "//table", mydoc, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null );
table = tables.iterateNext();
while (table)
{
var rows = mydoc.evaluate("tbody/tr", table, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
row = rows.iterateNext();
while (row)
{
var tds = mydoc.evaluate("td", row, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null)
td = tds.iterateNext()
while(td)
{
// TODO: store content in an array to process later
print('*' + td.textContent);
td = tds.iterateNext();
}
row = rows.iterateNext();
}
table = iterator.iterateNext();
}
This seems a little nasty as all the XPath examples seem to do their processing in one step. There appear to be few non-trivial examples where two types of data (e.g. labels and values in a table) are selected and combined. I can use the following selectors, but I end up with two lists with no structure:
//table/tbody/tr/td[#class='label']
//table/tbody/tr/td/a[#class='value']
(I know I'm using XPath for HTML parsing for which it wasn't really intended, but it seems to work so far.)

There appear to be few non-trivial
examples where two types of data (e.g.
labels and values in a table) are
selected and combined. I can use the
following selectors, but I end up with
two lists with no structure:
//table/tbody/tr/td[#class='label']
//table/tbody/tr/td/a[#class='value']
Use:
//table/tbody/tr/td[#class='label']
|
//table/tbody/tr/td/a[#class='value']
This single XPath expression selects all the wanted nodes (all XPath engines I am aware of return the selected nodes in document order). The | (union) operator produces the set union of its arguments.
If the (x)Html document has regular structure, you may expect in the returned result every selected td element (label) to be followed by its corresponding a element (value)

If it's on the main HTML page, you could just do:
for(var tables=document.getElementsByTagName("table"),i=0;i<tables.length;++i)
for(var rows=tables[i].getElementsByTagName("tr"),j=0;j<rows.length;++j)
for(var cells=rows[j].getElementsByTagName("td"),k=0;k<cells.length;++k)
print("*"+cells[i].textContent);
getElementsByTagName does /not/ return an array - it returns a live NodeList similar to ORDERED_NODE_ITERATOR_TYPE.