I tried to match the sql values string (0),(5),(12),... or (0,11),(122,33),(4,51),... or (0,121,12),(31,4,5),(26,227,38),... and so on with the regular expression
\(\s*\d+\s*(\s*,\s*\d+\s*)*\)(\s*,\s*\(\s*\d+\s*(\s*,\s*\d+\s*)*\))*
and it works. But...
How can I ensure that the regex does not match a values string like (0,12),(1,2,3),(56,7) with different number of columns?
Thanks in advance...
As i mentioned in comment to the question, the best way to check if input string is valid: contains the same count of numbers between brackets, is to use client side programm, but not clear SQL.
Implementation:
List<string> s = new List<string>(){
"(0),(5),(12)", "(0,11),(122,33),(4,51)",
"(0,121,12),(31,4,5),(26,227,38)","(0,12),(1,2,3),(56,7)"};
var qry = s.Select(a=>new
{
orig = a,
newst = a.Split(new string[]{"),(", "(", ")"},
StringSplitOptions.RemoveEmptyEntries)
})
.Select(a=>new
{
orig = a.orig,
isValid = (a.newst
.Sum(b=>b.Split(new char[]{','},
StringSplitOptions.RemoveEmptyEntries).Count()) %
a.newst.Count()) ==0
});
Result:
orig isValid
(0),(5),(12) True
(0,11),(122,33),(4,51) True
(0,121,12),(31,4,5),(26,227,38) True
(0,12),(1,2,3),(56,7) False
Note: The second Select statement gets the modulo of sum of comma instances and the count of items in string array returned by Split function. If the result isn't equal to zero, it means that input string is invalid.
I strongly believe there's a simplest way to achieve that, but - at this moment - i don't know how ;)
:(
Unless you add some more constraints, I don't think you can solve this problem only with regular expressions.
It isn't able to solve all of your string problems, just as it cannot be used to check that the opening and closing of brackets (like "((())()(()(())))") is invalid. That's a more complicated issue.
That's what I learnt in class :P If someone knows a way then that'd be sweet!
I'm sorry, I spent a bit of time looking into how we could turn this string into an array and do more work to it with SQL but built in functionality is lacking and the solution would end up being very hacky.
I'd recommend trying to handle this situation differently as large scale string computation isn't the best way to go if your database is to gradually fill up.
A combination of client and serverside validation can be used to help prevent bad data (like the ones with more numbers) from getting into the database.
If you need to keep those numbers then you could rework your schema to include some metadata which you can use in your queries, like how many numbers there are and whether it all matches nicely. This information can be computed inexpensively from your server and provided to the database.
Good luck!
Ok, I'm totally at a loss with this....
I think I have looked at every example and every code snippet around and still can't work out how to implement a custom sorter on my ObjectListView.
My primary column (column 0) contains numbers only (as a string) but is sorting all items by alphanumeric instead of numeric, meaning that it is doing something like this:
1
11
111
2
22
etc.
I am trying to find a relatively simple example of how to modify my ObjectListView to sort column 0 when it first loads, but I'm struggling.
I have converted over a custom class called ColumnSorter (from CodeProject) into VB and I'm calling the following delegate:
lvwColumnSorter = New CustomLVSorter.CustomLVSorter()
lsv_OpenTickets.CustomSorter = Sub(column As OLVColumn, order As SortOrder)
lvwColumnSorter.ColumnToSort = Ticket_Status.Index
lvwColumnSorter._SortModifier = CustomLVSorter.CustomLVSorter.SortModifiers.SortByText
lvwColumnSorter.OrderOfSort = SortOrder.Ascending
lsv_OpenTickets.ListViewItemSorter = lvwColumnSorter
End Sub
I get no errors, but I also get no change.
Any help would be greatly appreciated.
Well, are you sure you have looked at every example? I think there are a lot of resources on this one.
When you're using a list, datagridview, or any main form, you can adjust it to use a custom sorter. You create a custom IComparer, i.e. the definition of how you sort something. It can be as simple as converting the string (like yours) to an int with CInt() and returning -1 or +1 if it is greater or less than the last value. This is very common.
If you need help on the basics of how to do it, of course there are always the microsoft links that give you the basics such as Custom Sort I Comparer. But there is a stack flow that also follow your problem here: Custom sort C#
It's in C#, but there are many converters on that around here.
But the easiest way to get around it? Convert your string list into a integer list. Then it will sort perfectly.
I'd like to know if there's any way how to use auto indexing for range lookup. If I query something like
START age=node:node_auto_index(age<20 and age>10)
RETURN age;
it returns
Exception in thread "main" string literal or parameter expected.
I also tried something like
START age=node:node_auto_index(age = range(10,20))
RETURN age;
but it looks like it needs just age = "15" or something like that.
Any ideas what to do please?
The Lucene documentation states that the range syntax is as follows:
age:[10 TO 20]
The resulting query (but haven't tested this):
START age=node:node_auto_index("age:[10 TO 20]")
RETURN age;
The following read might also be interesting for you: Range queries in Neo4j using Lucene query syntax
EDIT: not sure if it will work for you; check out this github issue.
Why not to use where clause, something like below?
START node=node:node_auto_index(name='PersonName')
where node.age > 20 and node.age <20
RETURN node.age;
Following a workshop with Stefan Armbruster from Neo4J Technologies the same topic came up.
The most basic solution we came up with was to make sure that all the values stored for the numeric property has the same length. Thus, one will need to pad the age property values as follows, 011, 099, 103... And the values are stored as strings not numeric values.
Doing this everything should work from the index.
Can and/or be nested in filters?
I want to filter something like this... a=1 AND ( d=NULL OR d>5 )
Can anyone help?
You can use a Lucene query string like this in elastic search:
http://www.elasticsearch.org/guide/reference/query-dsl/query-filter.html
and here is a reference to how you can use () for grouping ... one thing to note is the I found prefixing group statements with the + must have symbol returns more accurate results.
http://lucene.apache.org/java/3_2_0/queryparsersyntax.html
grouping is at the end.
... oh and if you going to use greater than RangeQuery can cover this case by
setting either the upper or lower term to null.
J.
This may be a bit late, but if anyone else is looking for this, I found that search word AND filters are easy to add. Just use more words in the query and separate them with space.
Scala Example:
val queryString = client.prepareSearch().setQuery(QueryBuilders.matchQuery("json.path.to.node", "sky car")).setSize(MAX_RESULTS)
val response = queryString.execute().actionGet()
Now response will have all results which containt both sky AND car
Here is the single line from one of my functions to test if any objects in my array have a given property with a matching value
Return ((From tag In DataCache.Tags Where (tag.FldTag = strtagname) Select tag).Count = 1)
WHERE....
DataCache.Tags is an array of custom objects
strtagname = "brazil"
and brazil is definitely a tag name stored within one of the custom objects in the array.
However the function continually returns false.
Can someone confirm to me that the above should or should not work.
and if it wont work can someone tell me the best way to test if any of the objects in the array contain a property with a specific value.
I suppose in summary I am looking for the equivalent of a SQL EXISTS statement.
Many thanks in hope.
Your code is currently checking whether the count is exactly one.
The equivalent of EXISTS in LINQ is Any. You want something like:
Return DataCache.Tags.Any(Function(tag) tag.FldTag = strtagname)
(Miraculously it looks like that syntax may be about right... it looks like the docs examples...)
Many Thanks for the response.
Your code did not work. Then I realised that I was comparing to an array value so it would be case sensitive.
However glad I asked the question, as I found a better way than mine.
Many thanks again !