I have sqlite database with article table that contains articleID and articleDescription.
I'm using expressjs as server:
app.get('/articleDetail/:id',function(req,res){
res.sendFile(path.join(__dirname+'/articleDetail.html'));
var id = req.params.id;
var query = "select * from article where articleID = " + id;
});
I want the to show the content of the article based on its id in the database.
An example: when you select article 5 on the home page, it take you to url ..../articleDetail/5 and the content is shown to the user.
Summary of the 2 questions I have:
How can I connect and id in my database to the id of the url/route?
How can I show the correct article content based on its id using express?
Thanks for any help.
Install module called sqlite3 into your project. It provides exactly what you want, here you can see detailed guide on how to install it and use it for connecting and querying database - http://www.sqlitetutorial.net/sqlite-nodejs/connect/
So steps should be like this:
Get article id from request or url params e.g let id = req.params.id
Execute query and get the item from database
pass the value (article) object to view and render there
app.get('/articleDetail/:id',function(req,res){
var id = req.params.id;
var query = "select * from article where articleID = " + id;
// execute the query here
res.sendFile(path.join(__dirname+'/articleDetail.html'));
});
If I know the Room Id of a group can I get the list of online users in that group without joining the group? like,
QBGroupChat currentChatRoom =
groupChatManager.createGroupChat(groupDialog.getRoomJid());
Collection<Integer> onlineGroupUsers = null;
try {
onlineRoomUsers = currentChatRoom.getOnlineUsers();
} catch (XMPPException e) {
}
Please not that I didn't join the group, just got the room id from the Dialog.
You don't need to join chat to get the list of users, you just need to get the particular dialog using cycle, if you know the dialog's ID from QB.chat.dialog.list()
After you found the dialog, you can get the list of its users by occupants_ids
To get more information, please have a look at http://quickblox.com/developers/Chat#Retrieve_dialogs
I am working in a School Management project.The structure is when i am adding any new item in my project i have a single graph table where every item is generating a unique Graph Id, now i am having Cart where user can buy a book from it and that Cart contains GraphId of the item.
My problem is i want to search all the tables in database where that Item GraphId match the graphId in every table it give me the json of whole row of the table in which it exits
var searchgraphId = from m in db.OfflineCarts select m;
searchgraphId = searchgraphId.Where(s => s.UserId == loginuserinfoid);
foreach (var c in searchgraphId)
{
graphId = c.ListOfGraphIds;
}
This i have done where it will find all the graph ids belongs to login userid and it will get its carts item and now how to proceed??
you have to search graph id in all tables individual
your search will be as like
var searchgraphIdInUser = from m in db.UserInfo where m.GraphId == graphId select m;
foreach (var c in searchgraphIdInUser )
{
var user = db.UserInfoId.Find(c.UserInfoId)
// delete the row data here
}
i'm searching for a long time now to solve my problem but nearly found nothing helpful.
Hopefully some of you can give me a tip.
I have a relation A with the following format: username, timestamp, ip
For example:
Harald 2014-02-18T16:14:49.503Z 123.123.123.123
Harald 2014-02-18T16:14:51.503Z 123.123.123.123
Harald 2014-02-18T16:14:55.503Z 321.321.321.321
And i want to find out, who changed his ip adress in less then 5 seconds. So the second and the third row should be interesting.
I want do group the relation by username und want to compare the timestamp of the actuall row with the next row. if the ip adress isnt the same and the timestamp is less then 5 seconds bigger, this should be at the output.
could someone help me with that issue?
regards.
first i want to thank you for your time.
but i actually stuck at the Sessionize part.
this is my data comming in:
aoebcu 2014-02-19T14:23:17.503Z 220.61.65.25
aoebcu 2014-02-19T14:23:14.503Z 222.117.144.19
aoebcu 2014-02-19T14:23:14.503Z 222.117.144.19
jekgru 2014-02-19T14:23:14.503Z 213.56.157.109
zmembx 2014-02-19T14:23:12.503Z 199.188.198.91
qhixcg 2014-02-19T14:23:11.503Z 203.40.104.119
and my code till now looks like this:
hijack_Reduced = FOREACH finalLogs GENERATE ClientUserName, timestamp, OriginalClientIP;
hijack_Filtered = FILTER hijack_Reduced BY OriginalClientIP != '-';
hijack_Sessionized = FOREACH (GROUP hijack_Filtered BY ClientUserName) {
views = ORDER hijack_Filtered BY timestamp;
GENERATE FLATTEN(Sessionize(views)) AS (ClientUserName,timestamp,OriginalClientIP,session_id);
}
but when i run this script, i got the following error Message:
15:36:22 ERROR -
org.apache.pig.tools.pigstats.SimplePigStats.setBackendException(542)
| ERROR 0: Exception while executing [POUserFunc (Name:
POUserFunc(datafu.pig.sessions.Sessionize)[bag] - scope-199 Operator
Key: scope-199) children: null at []]:
java.lang.IllegalArgumentException: Invalid format: "aoebcu"
i already tried a lot, but nothing worked.
do you got an idea?
Regards
While you could write a UDF for this, you can actually make use of the UDFs already available in Apache DataFu to solve this.
My solution involves applying sessionization to the data. Basically you look at consecutive events and assign each event a session ID. If the time elapsed between two events exceeds a specified amount of time, in your case 5 seconds, then the next event gets a new session ID. Otherwise consecutive events get the same session ID. Once each event is assigned its session ID the rest is easy. We group by session ID and look for sessions that have more than one distinct IP address.
I'll walk through my solution.
Suppose you have the following input data. Both Harold and Kumar change their IP addresses. But Harold does it within 5 seconds, while Kumar does not. So the output of our script should just be simply "Harold".
Harold,2014-02-18T16:14:49.503Z,123.123.123.123
Harold,2014-02-18T16:14:51.503Z,123.123.123.123
Harold,2014-02-18T16:14:55.503Z,321.321.321.321
Kumar,2014-02-18T16:14:49.503Z,123.123.123.123
Kumar,2014-02-18T16:14:55.503Z,123.123.123.123
Kumar,2014-02-18T16:15:05.503Z,321.321.321.321
Load the data
data = LOAD 'input' using PigStorage(',')
AS (user:chararray,time:chararray,ip:chararray);
Now define a couple UDFs from DataFu. The Sessionize UDF performs sessionization as I described earlier. The DistinctBy UDF will be used to find the distinct IP addresses within each session.
define Sessionize datafu.pig.sessions.Sessionize('5s');
define DistinctBy datafu.pig.bags.DistinctBy('1');
Group the data by user, sort by time, and apply the Sessonize UDF. Note that the timestamp must be the first field, as this is what Sessionize expects. This UDF appends a session ID to each tuple.
data = FOREACH data GENERATE time,user,ip;
data_sessionized = FOREACH (GROUP data BY user) {
views = ORDER data BY time;
GENERATE flatten(Sessionize(views)) as (time,user,ip,session_id);
}
Now that the data is sessionized, we can group by the user and session. I group by user too because I want to spit this value back out. We pass the bag of events into the DistinctBy UDF. Check the documentation of this UDF for a more detailed description. But essentially we will get as many tuples as there are distinct IP addresses per session. Note that I have removed the time from the relation below. This is because 1) it isn't needed, and 2) the DistinctBy in 1.2.0 of DataFu has a bug when handling fields containing dashes, as the time field does.
data_sessionized = FOREACH data_sessionized GENERATE user,ip,session_id;
data_sessionized = FOREACH (GROUP data_sessionized BY (user, session_id)) GENERATE
group.user as user,
SIZE(DistinctBy(data_sessionized)) as distinctIpCount;
Now select all the sessions that had more than one distinct IP address and return the distinct users for these sessions.
data_sessionized = FILTER data_sessionized BY distinctIpCount > 1;
data_sessionized = FOREACH data_sessionized GENERATE user;
data_sessionized = DISTINCT data_sessionized;
This produces simply:
Harold
Here is the full source code, which you should be able to paste directly into the DataFu unit tests and run:
/**
define Sessionize datafu.pig.sessions.Sessionize('5s');
define DistinctBy datafu.pig.bags.DistinctBy('1'); -- distinct by ip
data = LOAD 'input' using PigStorage(',') AS (user:chararray,time:chararray,ip:chararray);
data = FOREACH data GENERATE time,user,ip;
data_sessionized = FOREACH (GROUP data BY user) {
views = ORDER data BY time;
GENERATE flatten(Sessionize(views)) as (time,user,ip,session_id);
}
data_sessionized = FOREACH data_sessionized GENERATE user,ip,session_id;
data_sessionized = FOREACH (GROUP data_sessionized BY (user, session_id)) GENERATE
group.user as user,
SIZE(DistinctBy(data_sessionized)) as distinctIpCount;
data_sessionized = FILTER data_sessionized BY distinctIpCount > 1;
data_sessionized = FOREACH data_sessionized GENERATE user;
data_sessionized = DISTINCT data_sessionized;
STORE data_sessionized INTO 'output';
*/
#Multiline private String sessionizeUserIpTest;
private String[] sessionizeUserIpTestData = new String[] {
"Harold,2014-02-18T16:14:49.503Z,123.123.123.123",
"Harold,2014-02-18T16:14:51.503Z,123.123.123.123",
"Harold,2014-02-18T16:14:55.503Z,321.321.321.321",
"Kumar,2014-02-18T16:14:49.503Z,123.123.123.123",
"Kumar,2014-02-18T16:14:55.503Z,123.123.123.123",
"Kumar,2014-02-18T16:15:05.503Z,321.321.321.321"
};
#Test
public void sessionizeUserIpTest() throws Exception
{
PigTest test = createPigTestFromString(sessionizeUserIpTest);
this.writeLinesToFile("input",
sessionizeUserIpTestData);
List<Tuple> result = this.getLinesForAlias(test, "data_sessionized");
assertEquals(result.size(),1);
assertEquals(result.get(0).get(0),"Harold");
}
I have an SecurityGroup entity witch has Memebers and Application properties.
Application is a lookup.
So securityGroups is in many-to-many relationship with User table and one-to-many with LookupApplciation (FK)
Now I want to select all application linked to a specific user.
I have follow criteria:
public IList<LookupApplication> GetApplicationByUser(User user)
{
return
this.Session.CreateCriteria(typeof(SecurityGroup), "sg")
.CreateAlias("Members", "u")
.CreateAlias("Application", "al")
.Add(Restrictions.Eq("u.Id", user.Id))
.List<LookupApplication>();
}
It trows an exception
The value "Edi.Advance.Core.Model.Security.SecurityGroup" is not of type "Edi.Advance.Core.Model.Lookups.LookupApplication" and cannot be used in this generic collection.
Parameter name: value
and it is right.
How can I transform the result to IList<LookupApplication>?
Thanks
You can only return the type which you create the criteria from.
The easiest way starting from the code you have will be:
return
this.Session.CreateCriteria(typeof(SecurityGroup), "sg")
.CreateAlias("Members", "u")
.CreateAlias("Application", "al")
.Add(Restrictions.Eq("u.Id", user.Id))
.List<SecurityGroup>()
// get the lookup applications in memory
.SelectMany(x => x.LookupApplications);
This loads all SecurityGroups into memory, even if it only needs the LookupApplications. This might not be an issue when you need them anyway or when they are small.
You could also reverse the query and start from the LookupApplication
return
this.Session.CreateCriteria(typeof(LookupApplication), "la")
// requires navigation path from SecurityGroup to LookupApplication
.CreateCriteria("la.SecurityGroup", "sg")
.CreateAlias("Members", "u")
.CreateAlias("Application", "al")
.Add(Restrictions.Eq("u.Id", user.Id))
.List<LookupApplication>()
Or use HQL, which has some features not available in Criteria, items gets all the items from a collection:
select sg.LookupApplications.items
from SecurityGroup sg inner join sg.Members u
where u.Id = :userId
HQL is actually recommended when you don't have dynamic queries.
Update, from isuruceanu's comment:
Session
.CreateQuery(
#"select sg.Application
from SecurityGroup sg
inner join sg.Members u
where u.Id = :userId")
.SetParameter("userId", user.Id)
.List<LookupApplication>();
It depends on how the SecurityGroup looks like and how LookupApplication looks like.
You could use ResultTransformer like:
.SetResultTransformer(Transformers.AliasToBean<LookupApplication>())
.List<LookupApplication>();
Granted that SecurityGroup has properties matchinig LookupAppliaction, or else you have to project those properties like:
.SetProjection(NHibernate.Criterion.Projections.ProjectionList()
.Add(Projections.Property("Number"), "OrderNumber")
.Add(Projections.Property("CreatedOn"), "CreatedOn")
.Add(Projections.Property("MemeberName"), "Name"))
.SetResultTransformer(Transformers.AliasToBean<LookupApplication>())
.List<LookupApplication>();