so I have been trying for quite some time to impelement the Graphity on neo4j
But i can find a way to build the queries, anyone have any leads?
for example on the neo4j document for Graphity there is a query just to get only the first element on the chain. how do i get the second one?
and also why there is an order by in the query? isn't that algorithm suppose to eliminate that?
Here is the query:
MATCH p=(me { name: 'Jane' })-[:jane_knows*]->(friend),(friend)-[:has]->(status)
RETURN me.name, friend.name, status.name, length(p)
ORDER BY length(p)
[UPDATED]
That is a variable-length query (notice the * in the relationship pattern), and it gets all the elements in the chain in N result rows (where N is the length of the chain). Each result row's path will contain the previous row's path (if there was a previous row) plus the next element in the chain. And, because every row has a different path length, ordering by the path length makes sense.
If you want to see the names (in order) of all the statuses for each friend, this query should do that:
MATCH p=(me { name: 'Jane' })-[:jane_knows*]->(friend)
WITH me, friend, LENGTH(p) AS len
MATCH (friend)-[:has|next*]->(status)
RETURN me.name, friend.name, COLLECT(status.name), len
ORDER BY len;
With the same data as in the linked example, the result is:
+-----------------------------------------------------+
| me.name | friend.name | COLLECT(status.name) | len |
+-----------------------------------------------------+
| "Jane" | "Bill" | ["Bill_s1","Bill_s2"] | 1 |
| "Jane" | "Joe" | ["Joe_s1","Joe_s2"] | 2 |
| "Jane" | "Bob" | ["Bob_s1"] | 3 |
+-----------------------------------------------------+
Related
I have Sessions table
Sessions
|Timespan|Name |No|
|12:00:00|Start|1 |
|12:01:00|End |2 |
|12:02:00|Start|3 |
|12:04:00|Start|4 |
|12:04:30|Error|5 |
I need to extract from it duration of each session using KQL (but if you could give me suggestion how I can do it with some other query language it would be also very helpful). But if next row after start is also start, it means session was abandoned and we should ignore it.
Expected result:
|Duration|SessionNo|
|00:01:00| 1 |
|00:00:30| 4 |
You can try something like this:
Sessions
| order by No asc
| extend nextName = next(Name), nextTimestamp = next(timestamp)
| where Name == "Start" and nextName != "Start"
| project Duration = nextTimestamp - timestamp, No
When using the operator order by, you are getting a Serialized row set, which then you can use operators such as next and prev. Basically you are seeking rows with No == "Start" and next(Name) == "End", so this is what I did,
You can find this query running at Kusto Samples open database.
let Sessions = datatable(Timestamp: datetime, Name: string, No: long) [
datetime(12:00:00),"Start",1,
datetime(12:01:00),"End",2,
datetime(12:02:00),"Start",3,
datetime(12:04:00),"Start",4,
datetime(12:04:30),"Error",5
];
Sessions
| order by No asc
| extend Duration = iff(Name != "Start" and prev(Name) == "Start", Timestamp - prev(Timestamp), timespan(null)), SessionNo = prev(No)
| where isnotnull(Duration)
| project Duration, SessionNo
I would like to create a short Catalog for myself out of a database which would show what tables and fields are available there with the combination of SAPPLY(), LAPPLY() etc. and DBListNames.
So far I only get this far but it returns a "0" character variable:
catalog <- lapply(list_of_tables, function(t) dbListFields(con, name = paste0(t)))
So I would like to create an output like this:
+------------+--------------------+
| DB TABLES | FIELDS |
+------------+--------------------+
| ORDERS | "PRODUCT", "TIME" |
| CLIENTS | "ID", "NAME" |
| PROMOTIONS | "DATE", "DISCOUNT" |
+------------+--------------------+
I haven't used these kind of loops and I would like to start it here..
Thank you for your support in advance!
I have a spreadsheet where dates are being recorded in regards to individuals, with additional data, as such:
Tom | xyz | 5/2/2012
Dick | foo | 5/2/2012
Tom | bar | 6/1/2012
On another sheet there is a line in which I want to be able to put in the name, such as Tom, and retrieve on the following cell through a formula the data for the LAST (most recent by date) entry in the first sheet. So the first sheet is a log, and the second sheet displays the most recent one. In the following example, the first cell is entered and the remaining are formulas displaying data from the first sheet:
Tom | bar | 6/1/2012
and so on, showing the latest dated entry in the log.
I'm stumped, any ideas?
If you only need to do a single lookup, you can do that by adding two new columns in your log sheet:
Sheet1
| A | B | C | D | E | F
1 | Tom | xyz | 6/2/2012 | | * | *
2 | Dick | foo | 5/2/2012 | | * | *
3 | Tom | bar | 6/1/2012 | | * | *
Sheet2
| A | B | C
1 | Tom | =Sheet1.E1 | =Sheet1.F1
*(E1) = =IF(AND($A1=Sheet2.$A$1;E2=0);B1;E2)
(i.e. paste the formula above in E1, then copy/paste it in the other cells with *)
Explanation: if A is not what you're looking for, go for the next; if it is, but there is a non-empty next, go for the next; otherwise, get it. This way you're selecting the last one corresponding to your search. I'm assuming you want the last entry, not "the one with the most recent date", since that's what you asked in your example. If I interpreted your question wrong, please update it and I can try to provide a better answer.
Update: If the log dates can be out of order, here's how you get the last entry:
*(F1) = =IF(AND($A1=Sheet2.$A$1;C1>=F2);C1;F2)
*(E1) = =IF(C1=F1;B1;E2)
Here I just replaced the test F2=0 (select next if non-empty) for C1>=F2 (select next if more recent) and, for the other column, select next if the first test also did so.
Disclaimer: I'm very inexperienced with spreadsheets, the solution above is ugly but gets the job done. For instance, if you wanted a 2nd row in Sheet2 to do another lookup, you'd need to add two more columns to Sheet1, etc.
+----------+------------+------+------+--------------+---------+---------+
| | SUBJ | MIN | MAX | RESULT | STATUS | PERCENT |
| +------------+------+------+--------------+---------+---------+
| | Subj1 | 35 | 100 | 13 | FAIL | 13.00% |
|EXAM NAME | Subj2 | 35 | 100 | 63 | PASS | 63.00% |
| | Subj3 | 35 | 100 | 35 | PASS | 35.00% |
| +------------+------+------+--------------+---------+---------+
| | Total | 105 | 300 | 111 | PASS | 37.00% |
+----------+------------+------+------+--------------+---------+---------+
This is my report viewer report format.The SubTotal row counts the
total of all the above column.Every thing is fine. But in the status
column its showing Pass. I want it to show fail if there is single
fail in the status column. I am generating Status if Result < Min then
it is fail or else it is pass. Now how to change the SubTotal row
below depending upon the condition. And is there any way to show the
Subtotal row directly from database. Any suggestion.
The easiest way to do this would be to use custom code (right-click non-display area of report, choose Properties and click the Code tab) - calculate the pass/fail score in the detail, display it in the group footer and reset it in the group header:
Dim PassFail As String
// Reset Pass or Fail status in group header
Public Function ResetAndDisplayStatusTitle() AS String
PassFail = "PASS" // Initialise status to pass
ResetAndDisplayStatusTitle = "Status"
End Function
// Calculate pass/fail on each detail row and remember any fails
Public Function CalculatePassFail() As String
Dim ThisResult As String
// Calculate whether this result is pass or fail
If Fields!Result.Value < Fields!Min.Value Then
ThisResult = "FAIL"
Else
ThisResult ="PASS"
End If
// Remember any failure as overall failure
If ThisResult = "FAIL" Then PassFail = "FAIL"
CalculatePassFail = ThisResult
End Function
Then you tie in the custom code to your cells in your table as follows:
In the value for the status column in your group header you put:
=Code.ResetAndDisplayStatusTitle()
In the value for the status column in the detail row you put:
=Code.CalculatePassFail()
In the value for the status column in the group footer you put:
=Code.PassFail
With respect to getting the subtotal row from the database directly from the database, there are a couple of ways depending on what result you are after.
Join the detail row to a subtotalling row in your SQL (so that the subtotal fields appear on every row in the dataset) and use those fields.
Again, use custom code (but this is probably overly complicated for subtotalling)
However, these tricks are only for strange circumstances and in general the normal out-of-the-box subtotalling can be tweaked to give the result you are after. If there is something specific you want to know, it is probably best to explain the problem in a separate question so that issue can be dealt with individually.
Months ago I ended up with a sub statement that originally worked with my input data. It has since stopped working causing me to re-examine my ugly process. I hate to share it but it accomplished several things at once:
active$id[grep("CIR",active$description)] <- sub(".*CIR0*(\\d+).*","\\1",active$description[grep("CIR",active$description)],perl=TRUE)
This statement created a new id column by finding rows that had an id embedded in the description column. The sub statement would find the number following a "CIR0" and populate the id column iff there was an id within a row's description. I recognize it is inefficient with the embedded grep subsetting either side of the assignment.
Is there a way to have a 'sub' replacement be NA or empty if the pattern does not match? I feel like I'm missing something very simple but ask for the community's assistance. Thank you.
Example with the results of creating an id column:
| name | id | description |
|------+-----+-------------------|
| a | 343 | Here is CIR00343 |
| b | | Didn't have it |
| c | 123 | What is CIR0123 |
| d | | CIR lacks a digit |
| e | 452 | CIR452 is next |
I was struggling with the same issue a few weeks ago. I ended up using the str_match function from the stringr package. It returns NA if the target string is not found. Just make sure you subset the result correctly. An example:
library(stringr)
str = "Little_Red_Riding_Hood"
sub(".*(Little).*","\\1",str) # Returns 'Little'
sub(".*(Big).*","\\1",str) # Returns 'Little_Red_Riding_Hood'
str_match(str,".*(Little).*")[1,2] #Returns 'Little'
str_match(str,".*(Big).*")[1,2] # Returns NA
I think in this case you could try using ifelse(), i.e.,
active$id[grep("CIR",active$description)] <- ifelse(match, replacement, "")
where match should evaluate to true if there's a match, and replacement is what that element would be replaced with in that case. Likewise, if match evaluates to false, that element's replaced with an empty string (or NA if you prefer).