I have a dynamic string that is generated like one of the following:
var q = "FROM Table SELECT avg(1), avg(2), avg(3) where x='y'
var q = "SELECT avg(1), avg(2), avg(3) FROM Table where z='x' since x days ago
The values after the select are also dynamic where there could be 1 select option, or 10. I'm trying to create some logic to always pluck whatever is selected into an array, but having trouble dealing with the dynamic nature (string being constructed dynamically AND the # of selects being dynamic).
Basically, end result something like this:
['avg(1)', 'avg(2)', 'avg(3)']
Currently I'm doing something like the following, but it always expects the string to be formatted in a certain order (always starting with SELECT and where after the fields to pluck):
let splitQ = q.match(".*SELECT(.*)where");
let selects = splitQ[1].trim().split(",");
Here is a working solution.
It makes these assumptions about the query (after lowercased).
the values come after the first instance of the word 'select '
if the query starts with 'from', values end before the first instance of ' where'
if the query starts with 'select', values end before the first instance of ' from'
const test1 = "FROM Table SELECT avg(1), avg(2), avg(3) where x='y'";
const test2 = "SELECT avg(1), avg(2), avg(3) FROM Table where z='x' since x days ago";
function extractValues(query) {
// in both scenarios, the values always come directly after 'select '
const valuesComeAfterMe = 'select ';
query = query.toLowerCase();
let valuesEndBeforeMe;
// conditionally handle both query syntaxes
if (query.startsWith('from')) {
valuesEndBeforeMe = ' where';
} else if (query.startsWith('select')) {
valuesEndBeforeMe = ' from';
} else {
throw Error('query not handled');
}
// remove start
query = query.slice(query.indexOf(valuesComeAfterMe) + valuesComeAfterMe.length);
// remove end
query = query.slice(0, query.indexOf(valuesEndBeforeMe));
// split values and trim whitespace
return query.split(',').map(item => item.trim());
}
console.log(extractValues(test1));
console.log(extractValues(test2));
Related
I'm dealing with an issue where the formatting on a CSV file that we're importing needs to be"pivoted" to match the formatting required for the program we are using to process the import.
Currently we are importing the file which comes with the following format:
Account
Department
Jan2022
Feb2022
Mar2022
12345
Sales
$456
$876
$345
98765
HR
$765
$345
$344
We need the format to hold the time periods in one column which would make each account be repeated per time period. For example:
Account
Department
Period
Amount
12345
Sales
Jan2022
$456
12345
Sales
Feb2022
$876
12345
Sales
Mar2022
$345
We are importing this CSV using JavaScript however its basic JS as the program does not support JQuery or any other JS library. Once we import the table into our staging area using JS, we can use SQL to modify the data as well, so this could be solved with either JS or SQL.
We are using a CSV to Array function to read the CSV file for importing into staging:
function CSVToArray(strData, strDelimiter) {
// Check to see if the delimiter is defined. If not, then default to comma.
strDelimiter = strDelimiter || ",";
// Create a regular expression to parse the CSV values.
var objPattern = new RegExp(
// Delimiters.
"(\\" +
strDelimiter +
"|\\r?\\n|\\r|^)" +
// Quoted fields.
'(?:"([^"]*(?:""[^"]*)*)"|' +
// Standard fields.
'([^"\\' +
strDelimiter +
"\\r\\n]*))",
"gi"
);
// Create an array to hold our data. Give the array a default empty first row.
var arrData = [[]];
// Create an array to hold our individual pattern matching groups.
var arrMatches = null;
// Keep looping over the regular expression matches until we can no longer find a match.
while ((arrMatches = objPattern.exec(strData))) {
// Get the delimiter that was found.
var strMatchedDelimiter = arrMatches[1];
// Check to see if the given delimiter has a length (is not the start of string) and if it matches
// field delimiter. If id does not, then we know that this delimiter is a row delimiter.
if (strMatchedDelimiter.length && strMatchedDelimiter !== strDelimiter) {
// Since we have reached a new row of data, add an empty row to our data array.
arrData.push([]);
}
//Now that we have our delimiter out of the way, let's check to see which kind of value we captured (quoted or unquoted).
var strMatchedValue;
if (arrMatches[2]) {
// We found a quoted value. When we capture this value, unescape any double quotes.
strMatchedValue = arrMatches[2]
.replace(new RegExp('""', "g"), '"')
.replace('"', "");
} else {
// We found a non-quoted value.
strMatchedValue = arrMatches[3];
}
// Now that we have our value string, let's add it to the data array.
arrData[arrData.length - 1].push(strMatchedValue);
}
// Return the parsed data.
return arrData;
}
UNPIVOT should work for you:
/* sample data */
with t as
(select '12345' account,
'Sales' department,
'$456' jan2022,
'$876' feb2022,
'$345' mar2022
from dual
union all
select '98765' account,
'HR' department,
'$765' jan2022,
'$345' feb2022,
'$344' mar2022
from dual)
select *
from t
unpivot include nulls(amount for period in(jan2022 as 'jan2022',
feb2022 as 'feb2022',
mar2022 as 'mar2022'));
If you have dynamic columns you gonna have bad time with this aproach - you have to generate "unpivot in clause" (that part with jan2022 as 'jan2022') on your own.
I am new in programing and right now I am working on one program. Program need to find the substring in a string and return the index where the chain starts to be the same. I know that for that I can use "indexOf". Is not so easy. I want to find out substrings with at moste one different char.
I was thinking about regular expresion... but not really know how to use it because I need to use regular expresion for every element of the string. Here some code wich propably will clarify what I want to do:
var A= "abbab";
var B= "ba";
var tb=[];
console.log(A.indexOf(B));
for (var i=0;i<B.length; i++){
var D=B.replace(B[i],"[a-z]");
tb.push(A.indexOf(D));
}
console.log(tb);
I know that the substring B and string A are the lowercase letters. Will be nice to get any advice how to make it using regular expresions. Thx
Simple Input:
A B
1) abbab ba
2) hello world
3) banana nan
Expected Output:
1) 1 2
2) No Match!
3) 0 2
While probably theoretically possible, I think it would very complicated to try this kind of search while attempting to incorporate all possible search query options in one long complex regular expression. I think a better approach is to use JavaScript to dynamically create various simpler options and then search with each separately.
The following code sequentially replaces each character in the initial query string with a regular expression wild card (i.e. a period, '.') and then searches the target string with that. For example, if the initial query string is 'nan', it will search with '.an', 'n.n' and 'na.'. It will only add the position of the hit to the list of hits if that position has not already been hit on a previous search. i.e. It ensures that the list of hits contains only unique values, even if multiple query variations found a hit at the same location. (This could be implemented even better with ES6 sets, but I couldn't get the Stack Overflow code snippet tool to cooperate with me while trying to use a set, even with the Babel option checked.) Finally, it sorts the hits in ascending order.
Update: The search algorithm has been updated/corrected. Originally, some hits were missed because the exec search for any query variation would only iterate as per the JavaScript default, i.e. after finding a match, it would start the next search at the next character after the end of the previous match, e.g. it would find 'aa' in 'aaaa' at positions 0 and 2. Now it starts the next search at the next character after the start of the previous match, e.g. it now finds 'aa' in 'aaaa' at positions 0, 1 and 2.
const findAllowingOneMismatch = (target, query) => {
const numLetters = query.length;
const queryVariations = [];
for (let variationNum = 0; variationNum < numLetters; variationNum += 1) {
queryVariations.push(query.slice(0, variationNum) + "." + query.slice(variationNum + 1));
};
let hits = [];
queryVariations.forEach(queryVariation => {
const re = new RegExp(queryVariation, "g");
let myArray;
while ((searchResult = re.exec(target)) !== null) {
re.lastIndex = searchResult.index + 1;
const hit = searchResult.index;
// console.log('found a hit with ' + queryVariation + ' at position ' + hit);
if (hits.indexOf(hit) === -1) {
hits.push(searchResult.index);
}
}
});
hits = hits.sort((a,b)=>(a-b));
console.log('Found "' + query + '" in "' + target + '" at positions:', JSON.stringify(hits));
};
[
['abbab', 'ba'],
['hello', 'world'],
['banana', 'nan'],
['abcde abcxe abxxe xbcde', 'abcd'],
['--xx-xxx--x----x-x-xxx--x--x-x-xx-', '----']
].forEach(pair => {findAllowingOneMismatch(pair[0], pair[1])});
In my Cordova app, I need to query a SQLite database and select rows where the value of the column EventName contains a substring. I want to be able to use ? to hold values to avoid SQL injection. I tried this query:
SELECT * FROM EventName WHERE 1 = 1 AND lower(EventName) LIKE lower('%?%');
This is my JavaScript code that I use to query the database:
function searchEvent(onSearch, eventName) {
// First create the query string
var params = [];
var query = "SELECT * FROM Event WHERE 1 = 1";
if (eventName != null && eventName != "") {
query += " AND lower(EventName) LIKE lower('%?%')";
params.push(eventName);
}
query += ";";
console.log(query); // Log the query
console.log(params); // Log the parameters
// Then execute query statement
db.transaction(function(tx) {
tx.executeSql(query, params, function(tx, rs) {
onSearch(rs);
});
}, function(err) {
console.log(err); // This statement was executed
});
}
This is the logged query:
SELECT * FROM Event WHERE 1 = 1 AND lower(EventName) LIKE
lower('%?%');
This is the logged paramaters:
[ 'myInput' ]
This is the error the was returned:
{
code: 5,
messsage: 'number of \'?\'s in statement string does not match argument count'
}
As you can see there is 1 ? placeholder and 1 input parameter so the numbers DO match. I think it is because the ? is between the single quotes ('') so it is thought to be a part of the searched string. How do I fix this?
EDIT:
The JavaScript statement "SELECT * FROM Event WHERE 1 = 1" + " AND lower(EventName) LIKE lower('%" + eventName + "%')" is ok, but I wanna use a method that can protect me against SQL injection
In order to prevent the eventName from SQL injection, check it with regEx validation to include only alphanumneric and whitelist specific special characters /^[ A-Za-z0-9_#./#&+-]*$/. Also try this regEx /^[a-zA-Z0-9!##\$%\^\&*)(+=._-]+$/g. I do not believe that ? would work with SQL SELECT statement, so you need to pass +eventname+
Hope it helps.
I have a script I have been using in my test environment to programmically create a tracking number by parsing the year from timestamp and padding the response index.
function setTrackingNumber(ss, lastRowInx, createDateColumn) //This block generates and stores a tracking number in Column AU on the backend
{
var padTrackNo = "" + lastRowInx;
var trackSize = 4;
var trackingNumberColumn = createDateColumn-3; //trackingNumberColumn is currently in AU (Column 47) Calculating using it's relative position to createDateColumn Position
if (ss.getRange(lastRowInx, trackingNumberColumn).getValue() == "") // so that subsequent edits to Google Form don't overwrite original tracking number
{
if (padTrackNo > trackSize)
{
var padTrackNo = pad(padTrackNo, trackSize);
}
else {} //do nothing
var shortYear = setShortYear(ss, lastRowInx, createDateColumn);
var trackingNumber = shortYear + "-" + padTrackNo;
var createTrackingNumber = ss.getRange(lastRowInx, trackingNumberColumn);
createTrackingNumber.setValue(trackingNumber);
}
else {} //should do nothing
return;
}//This is the end of the setTrackingNumber function
function setShortYear(ss, lastRowInx, createDateColumn)
{
var newCreateDate = ss.getRange(lastRowInx,createDateColumn).getValue();
var strDate = "" + newCreateDate;
var splitDate = strDate.split(" ");
var trimYear = splitDate[3];
var shortYear = trimYear;
return shortYear;
}//This is the end of the shortYear function
function pad(padTrackNo, trackSize)
{
while (padTrackNo.length < trackSize)
{
padTrackNo = "0"+padTrackNo;
}
return padTrackNo;
}//This is the end of pad function
That gets me test result which is as expected ex. 2016-0005. However when we added it to another production sheet it seemed to work with test data and then production data showed up like a date 3/1/2016. production result - first cell.
I thought it must just be formatting the string as a date because of the numbers so I tried formatted the column as plain text but that just changed the date to a plain text version of the date.
I thought this might be similar to needing to specify the format like I did in this question Appending initial timestamp from Google Form to end of record in order to permanently store create date onFormSubmit at #SandyGood 's suggestion so I tried setting the number format as [0000-0000] by changing
createTrackingNumber.setValue(trackingNumber);
to
createTrackingNumber.setValue(trackingNumber).setNumberFormat("0000-0000");
which resulted in the [production result - second cell] which again doesn't match the expected result.
Oddly, some submissions seem to work just fine like [production result - third cell]. Over the past 3 days and approximately 10 records it has been fine, then hinky, then fine, they hinky, then fine again. I am not really sure what else to try to debug this odd behaviour.
Note: I had to parse the date as a string as I was having trouble getting it to parse the date correctly from the create date which is taken from initial timestamp.
To my understanding, "2016-0005" is not a number but a string, so the cell containing it should be formatted as plain text. With a script, this can be done by
range.setNumberFormat('#STRING#')
(source), and this must be done before you set the value to the cell. Like this:
createTrackingNumber.setNumberFormat('#STRING#').setValue(trackingNumber);
In an implementation I am fetching list of values by doing substring.
For example below are list of values:
First list item = 'itemno1',second list item = 'itemno2',third list item = 'itemno3 ****disabled****'.
I am using a marker disabled to identify the value as a disabled one. So, when the user
adding a value, I am just appending a space and then appending the marker disabled after that. But while updating I want to discard the marker and only get the value.
So, I am using the function below:
function GetAppropriateListValue(listVal) {
return listVal.substring(0, Math.max(0, listVal.lastIndexOf(" ")) || Infinity);
}
The function above discards the rest of characters after the first space character.
But, in some other scenario, user can add an item with multiple spaces.
'itemno10 itemno10 ****disabled****'
Here I need to get the value after discarding the marker ****disabled****
How can I achieve this in JavaScript?
Thanks.
var str = 'itemno10 itemno10 *disabled*'
str = str.replace('*disabled*',""); // returns 'itemno10 itemno10 '
Not pretty but if you want a substring then
var s='itemno10 itemno10 *****disabled****';
var t='itemno11 itemno11';
s = s.slice(0,(s.indexOf(' *')!== -1)? s.indexOf(' *'):undefined);
t = t.slice(0,(t.indexOf(' *')!== -1)? t.indexOf(' *'):undefined);
alert(s + " " + t);