How can I get substring dynamically, I want to split one word into two parts one is a string and other to no,
AA112 this is my string so from sql query
SELECT substr(thisColumn, 1,2) AS String from thisTable
I am getting AA in the query the index(2) I am pasing is dynamic I am getting from some value, So here I am able to get the string now I want to get the number +1 like it is 112 then -> 113
I have tried several queries but it is not working, I have tried doing it with javascript substring but it didn't work out.
Sample output
AAA123 -> AAA and 124
AA4 -> AA and 5
BBBB8 -> BBBB and 9
const input="AA112";
var numberPattern = /\d+/g;
const number = input.match(numberPattern)[0];
const text = input.replace(number,"");
console.log(text); //AA
console.log(number); //112
const incremented = parseInt(number) + 1;
console.log(incremented);
Using LOCATE, IF,LEAST and SUBSTRING over two sub-query can achieve the output result you're looking for.
SELECT VAL,
SUBSTRING(VAL,1,FIRSTNUM-1),
SUBSTRING(VAL,FIRSTNUM,999)+1
FROM
(SELECT VAL,LEAST(V0+0,V1+0,V2+0,V3+0,V4+0,V5+0,V6+0,V7+0,V8+0,V9+0) FIRSTNUM FROM
(SELECT VAL,
IF(LOCATE(0,VAL)=0,999,LOCATE(0,VAL)) V0,
IF(LOCATE(1,VAL)=0,999,LOCATE(1,VAL)) V1,
IF(LOCATE(2,VAL)=0,999,LOCATE(2,VAL)) V2,
IF(LOCATE(3,VAL)=0,999,LOCATE(3,VAL)) V3,
IF(LOCATE(4,VAL)=0,999,LOCATE(4,VAL)) V4,
IF(LOCATE(5,VAL)=0,999,LOCATE(5,VAL)) V5,
IF(LOCATE(6,VAL)=0,999,LOCATE(6,VAL)) V6,
IF(LOCATE(7,VAL)=0,999,LOCATE(7,VAL)) V7,
IF(LOCATE(8,VAL)=0,999,LOCATE(8,VAL)) V8,
IF(LOCATE(9,VAL)=0,999,LOCATE(9,VAL)) V9 FROM mytable) A ) B;
Here I use LOCATE to find the location of the number occurrence in the value then REPLACE to change the value to 999 if it returns 0. This is essential for the next operation using LEAST because if I leave it 0, it'll return all 0 instead. The reason I use LEAST is because if you look at the 4th data example in the fiddle it's AAAAA321. This will return the result in grid like the following:
+----------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| VAL | V0 | V1 | V2 | V3 | V4 | V5 | V6 | V7 | V8 | V9 |
+----------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| AAA123 | 999 | 4 | 5 | 6 | 999 | 999 | 999 | 999 | 999 | 999 |
| AA4 | 999 | 999 | 999 | 999 | 3 | 999 | 999 | 999 | 999 | 999 |
| BBBB8 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 5 | 999 |
| AAAAA321 | 999 | 8 | 7 | 6 | 999 | 999 | 999 | 999 | 999 | 999 | <---this
| AAA45 | 999 | 999 | 999 | 999 | 4 | 5 | 999 | 999 | 999 | 999 |
+----------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
The first number occurrence is actually '3' but because I construct the query running from 0-9, I'll always get the first number in front (in this case '1' is the 8th occurrence) despite it being on the middle or last position. That's why LEAST will correctly take which number is actually located first using LOCATE function.
In the last outer query, I use the result from the LEAST function (assigned as FIRSTNUM) as the defining value for the SUBSTRING. The first substring I use it as the end location subtract by 1 to get the strings and in the second substring I use it as the first location to get the number (I end the location with 999).
Fiddle: https://www.db-fiddle.com/f/F15cxiYJxGcozYUbQukeB/5
Edit: I realized I cannot use REPLACE because if the location is like 10, it will replace 0 to 999 which makes it become 1999 instead. So I use IF.
Related
My dexiedb structure looks like below.
const db = new Dexie('shipment-execution');
db.version(1).stores({
root: '++id,shipmentid,stopid',
})
My IndexedDB will look like below
| id| shipmentid| stopid|
| 1 | 6000001 | 10 |
| 2 | 6000001 | 20 |
| 3 | 6000001 | 30 |
| 4 | 6000002 | 10 |
| 5 | 6000002 | 20 |
I am trying to get all the data which has shipmentid equal to 6000001. Each time it is returning only one record (the first record ).
db.root.where({shipmentid : '6000001'}).toArray().then((d)=>{
console.log(d);
})
output is only fetching the first record
| id| shipmentid| stopid|
| 1| 6000001 | 10 |
Please let me know, what I am doing wrong.
I have the following table:
+----------+----------+---------+----------+----------+----------+
| Date | A | B | C | P | D |
+----------+----------+---------+----------+----------+----------+
|2019-01-10| -111,000 | 666,000 | 78,000 | 45 | 120,000 |
|2019-01-09| 555,000 | 55,000 | 100,000 | 55 | 700,000 |
|2019-01-08| 48,000 | 30,000 | 40,000 | 65 | 450,000 |
|2019-01-07| 600,000 |-450,000 | -800,000 | 90 | 980,000 |
+----------+----------+---------+----------+----------+----------+
May I know how to create a temporary table from the existing table above to become the table as below:
+----------+----------+---------+----------+----------+
| Date |Components| Values | Comp_no | P |
+----------+----------+---------+----------+----------+
|2019-01-10| A |-111,000 | 1 | 45 |
|2019-01-10| B | 666,000 | 2 | 45 |
|2019-01-10| C | 78,000 | 3 | 45 |
+----------+----------+---------+----------+----------+
Then sort it according to absolute values as below:
Give numbers to the largest value as '1', 2nd largest as '2' and so on.
The sorted_comp_no represents the order whereby the components is sorted where '1' is 'B', '2' is A and '3' is C.
+----------+----------+---------+----------+----------+--------------+
| Date |Components| Values | comp_no | P | sort_sequence|
+----------+----------+---------+----------+----------+--------------+
|2019-01-10| A |-111,000 | 1 | 45 | 2 |
|2019-01-10| B | 666,000 | 2 | 45 | 1 |
|2019-01-10| C | 78,000 | 3 | 45 | 3 |
+----------+----------+---------+----------+----------+--------------+
Use the comp_no and sort.
The components are now sorted according to their values.
+----------+----------+---------+----------+----------+--------------+
| Date |Components| Values | comp_no | P |sorted_comp_no|
+----------+----------+---------+----------+----------+--------------+
|2019-01-10| B | 666,000 | 2 | 45 | 2 |
|2019-01-10| A |-111,000 | 1 | 45 | 1 |
|2019-01-10| C | 78,000 | 3 | 45 | 3 |
+----------+----------+---------+----------+----------+--------------+
I've already created the temporary table template but still stuck in taking the name of specific column only (A,B and C) to be put into a column of its own category ignoring column D . Column P is brought into the temporary table but remain as is. There is also a dependency to the date column as there are multiple data of different date.
But the end goal is to be able to "sort specific column according to its absolute value at a specific date dynamically".
I'm working on aggregating my city's main big intersections with my city's collision data. What am trying to accomplish is to determine the number of accidents which happened in and around the intersection within a 20 meters radius.
Luckily, I'm already far off in the project and I have two tables in my database intersections and collisions
My intersections table:
--------------------------------------------
| id | city | Latitude | Longitude |
--------------------------------------------
| 1 | 1 | 34.44444 | 84.3434 |
--------------------------------------------
| 2 | 1 | 42.4666667 | 1.4666667 |
--------------------------------------------
| 3 | 1 | 32.534167 | 66.078056 |
--------------------------------------------
| 4 | 1 | 36.948889 | 66.328611 |
--------------------------------------------
| 5 | 1 | 35.088056 | 69.046389 |
--------------------------------------------
| 6 | 1 | 36.083056 | 69.0525 |
--------------------------------------------
| 7 | 1 | 31.015833 | 61.860278 |
--------------------------------------------
MY collisions table:
--------------------------------------------
| id | cause | Latitude | Longitude |
--------------------------------------------
| 1 | 1 | 44.44444 | 81.3434 |
--------------------------------------------
| 2 | 1 | 32.4666667 | 1.4666667 |
--------------------------------------------
| 3 | 1 | 42.534167 | 63.078056 |
--------------------------------------------
| 4 | 1 | 46.948889 | 62.328611 |
--------------------------------------------
| 5 | 1 | 45.088056 | 61.046389 |
--------------------------------------------
| 6 | 1 | 46.083056 | 63.0525 |
--------------------------------------------
| 7 | 1 | 41.015833 | 69.860278 |
--------------------------------------------
Note: Some fields were omitted for simplicity sake
As you can see, both tables posses latitude and longitude fields. Now to determine if intersection and collision coordinates are close, I thought of using a MySQL query that takes an id of an intersection which then queries the collisions table to get all collisions within 20 meters of the intersection.
What is this query (in MySQL or in Sequelize)?
Here's what I have now (it's in Sequelize using a MySQL database)
// api/collisions/{intersection_id}/count
exports.intersection_accident_count = (req, res) => {
intersection.findOne({where: {equipement: req.params.intersection_id}}).then(intersection => {
let intersectionLongitude = intersection.longitude;
let intersectionLatitude = intersection.latitude;
collision.count({where: {
longitude: {
$gt: intersectionLongitude
},
latitude: {
$gt: intersectionLatitude
},
}}).then(count => {
res.status(200).json({'number_of_accidents': count});
});
});
};
You should start with straightforward way:
SELECT
i.*
FROM
intersections AS i
INNER JOIN collisions AS c ON (
ST_Distance_Sphere(POINT(i.Longitude, i.Latitude), POINT(c.Longitude, c.Latitude)) < #dist
)
This should give you results, however the query will not use any indexes at all and if you have many records it would be very slow.
You should think of adding geometry data types in your table:
ALTER TABLE `collisions` ADD COLUMN `Location` POINT;
UPDATE `collisions` SET Location = POINT(Longitude, Latitude);
ALTER TABLE `intersections` ADD COLUMN `Location` POINT;
UPDATE `intersections` SET Location = POINT(Longitude, Latitude);
You can add trigger so the Location will be populated automatically when you updating Longitude/Latitude.
Then:
SELECT
i.*
FROM
intersections AS i
INNER JOIN collisions AS c ON (
ST_Distance_Sphere(i.Location, c.Location) < #dist
)
This would be a bit faster.
If you'd like to make it even faster, you can add another geometry poligon Area column into your intersection table and 'pre-build' areas (can be round for accuracy or square for speed).
After that you will be able to do something like this:
SELECT
i.*
FROM
intersections AS i
INNER JOIN collisions AS c ON (
ST_WITHIN(c.Location, i.Area)
)
I have this quite long string that contains multiple information. So I guess we can say that its a couple of fields concatenated together without any delimiters. I understand that to make this work, all of the lengths of the fields should always be fixed. However, two of the fields represent a name and an amount and no prefixes/suffixes were implemented to maintain a fixed length.
I was wondering how would I got about this problem? Here's a sample of the string and how they should be separated:
Sample #1
Actual Input:
48001MCAbastillas2200800046300017100518110555130000123
How it should be separated:
480 | 01 | MCAbastillas | 2200800046300017 | 100518 | 110555 | 130000 | 123
Sample #2
Actual Input:
48004MCAbastillas22008000463000171005181105555000000123
How it should be separated:
480 | 04 | MCAbastillas | 2200800046300017 | 100518 | 110555 | 5000000 | 123
In my example only the amount has changed but I'm expecting that the name will vary in length as well. Any suggestion will be much appreciated.
I'd probably use a regular expression for this.
String test = "48004MCAbastillas22008000463000171005181105555000000123";
Pattern pattern = Pattern.compile("^(\\d{3})(\\d{2})([A-Za-z]+)(\\d{16})(\\d{6})(\\d{6})(\\d+)(\\d{3})$");
Matcher matcher = pattern.matcher(test);
if (matcher.matches())
{
for (int i = 1; i <= matcher.groupCount(); ++i)
{
System.out.print(matcher.group(i) + " | ");
}
}
Sample output:
480 | 04 | MCAbastillas | 2200800046300017 | 100518 | 110555 | 5000000
| 123 |
Note that the third and second to last groups do not have fixed lengths.
It's more difficult if the name can contain numbers. My approach would be to run this against the data that you have and print a list of anything that doesn't match (i.e. add an else clause). Perhaps then you can come up with a better strategy for handling these cases. For example, something like ([A-Za-z]+\w*[A-Za-z]+) might be an improvement, because that will at least allow numbers in the middle of the name.
Sometimes you just have to accept that when the data you're given is crap, you just have to do the best that you can and that might mean throwing some of it away.
We want the output
480 | 01 | MCAbastillas | 2200800046300017 | 100518 | 110555 | 130000
| 123
where the fields 3 and 7 had no fixed length.
Suppose that we store the string in a string var:
String s="48001MCAbastillas2200800046300017100518110555130000123";
We can find the fields 1 & 2 easly:
System.out.println(s.substring(0, 3)); //has 3 digit
System.out.println(s.substring(3, 5)); //has 2 digit
//we can reduce s
s=s.substring(6); //remove char from 0 to 5 included
If you'll call System.out.println(s); you well see
CAbastillas2200800046300017100518110555130000123
Now we have the string... I can deduce that it is composed only by char. So we have to find the first occurrence of a number... We can use a cycle:
int index=-1;
for( int i=0; i<s.length(); i++ ) {
if( Character.isDigit(s.charAt(i))) {
index=i;
System.out.println("There is a number in the position "+ index);
break;
}
}
Now you can extract your name with:
System.out.println(s.substring(0, index));
and extract the other 3 fields (you can optimize this part...)
System.out.println(s.substring(0, 16));
s=s.substring(16);
System.out.println(s.substring(0, 6));
s=s.substring(6);
System.out.println(s.substring(0, 6));
s=s.substring(6);
Finally, you can divide the remaining s in two part with length s.length.3 and 3:
System.out.println(s.substring(0, s.length()-3));
System.out.println(s.substring( s.length()-3,s.length()));
Your output will be:
480
01
There is a number in the position 11
CAbastillas
2200800046300017
100518
110555
130000
123
What does the +d in
function addMonths(d, n, keepTime) {
if (+d) {
mean?
The + operator returns the numeric representation of the object. So in your particular case, it would appear to be predicating the if on whether or not d is a non-zero number.
Reference here. And, as pointed out in comments, here.
Operator + is a unary operator which converts the value to a number. Below is a table with corresponding results of using this operator for different values.
+----------------------------+-----------+
| Value | + (Value) |
+----------------------------+-----------+
| 1 | 1 |
| '-1' | -1 |
| '3.14' | 3.14 |
| '3' | 3 |
| '0xAA' | 170 |
| true | 1 |
| false | 0 |
| null | 0 |
| 'Infinity' | Infinity |
| 'infinity' | NaN |
| '10a' | NaN |
| undefined | NaN |
| ['Apple'] | NaN |
| function(val){ return val }| NaN |
+----------------------------+-----------+
Operator + returns a value for objects which have implemented method valueOf.
let something = {
valueOf: function () {
return 25;
}
};
console.log(+something);
It is a unary "+" operator which yields a numeric expression. It would be the same as d*1, I believe.
As explained in other answers it converts the variable to a number. Specially useful when d can be either a number or a string that evaluates to a number.
Example (using the addMonths function in the question):
addMonths(34,1,true);
addMonths("34",1,true);
then the +d will evaluate to a number in all cases. Thus avoiding the need to check for the type and take different code paths depending on whether d is a number, a function or a string that can be converted to a number.