In MEAN Technology,I need to develop the payroll application,In this I have two fields code and name,But code and name should be unique,how to code this in mongodb?
Are you serious?
But still, do you mean code and name should be unique individually or do you mean the combination of code+name should be unique.
There is a difference, if code and name should be unique individually it means there cannot be same code in two different DB. if the combination should be unique means for one code there could be different names and vice versa.
I am going to provide a subjective answer as you haven't shown what you have tried or what you wish to try.
either you user _id as code+name making sure that it would be unique.
or you can have different key for code and name in document having a unique key indexing on both of them. or in second case having a compound unique indexing.
Related
I have a table in my postgres database, with a list of buildings called Buildings_national. In this table, I have a larger number of duplicates, and i need to point them out to have the duplicates deleted.
The thing is, that I need to leave out a single line for every duplicate group, to make sure that one example of the duplicated building is retained in the table.
All buildings has a unique identifier, and every line has a unique identifier as well.
Can anyone recommend a good way to do this? I guess what I am looking for, is a reversed distinct somehow?
I am using TitanDB with Cassandra as storage and ElasticSearch as Index. I found out that everytime you add Vertex in TitanDB, it generates a unique identifier.
All the elements I am adding into it, has already an identifier, this has been added as property of the Vertex.
My question is:
If I will add again a Vertex with the same id, How does TitanDB recognise that it is a duplicate?
Is it possible update element on duplicate key ? Or you have first to make a query within TitanDB? If so, isn't it a terrible waste of time doing so?
There is no direct method for "upsert". As noted above, in the comment on the question, the "getOrCreate" approach is the standard way to do this. So, "yes" you would need to do a lookup via index on your identifier property.
Titan can detect duplicates if you establish your indexed property with a unique constraint:
mgmt = graph.openManagement()
name = mgmt.getPropertyKey('name')
mgmt.buildIndex('byNameUnique', Vertex.class).addKey(name).unique().buildCompositeIndex()
mgmt.commit()
If the same property value is applied twice now, an exception will be generated on commit of the transaction. Use unique indexes wisely as they will affect performance especially if you expect heavy contention on the property that the unique is applied to.
I can't think of a better title, so feel free to make a suggestion once you understand the issue.
I was given a table to work with that I need to call from another table:
Name
Month
Type
Value
For each record in the main table I need to pull one "Value" that corresponds to it. What it is will be determined by all three of the other fields. So for example, if a record in the main table is:
Name:
Google
Date:
3\17\2016
Type:
M
Then I need to pull the value for the record in the other table where the Name is "Google", the month is "3", and the type is "M".
I was able to do this successfully (if slowly) using an ExecuteSQL command in a calculation field, with a ton of nested If statements for the names (I have yet to figure out how to input the record's data directly into the ExecuteSQL statement, it breaks when I try). I would prefer to just grab the data directly. I can't switch over to the other layout because I need to see all of the records at once. I can't do a simple relationship because there isn't a real relationship, it's like there are three foreign keys working in tandem and I only know how to use one to call the data.
Any idea on how to do this more simplistically?
Some ideas I've had but not sure if it will work:
Using a calculation field as a related field to dynamically point to the row by code (concatenate the three relevant fields into a type of code). Not sure if you can connect two tables by a calculation field.
Doing that same thing when calling the data into the table in the first place, adding a code to create a single primary key.
Here are my relationships:
I can't do a simple relationship because there isn't a real
relationship, it's like there are three foreign keys working in tandem
and I only know how to use one to call the data.
Simply define a relationship with three predicates - i.e. three pairs of match fields.
Is it possible, in SQL Server 2008, using the full text index syntax, to run a query such as this one?
SELECT *
FROM TABLE_TO_SEARCH S,
TABLE_WITH_STRINGS_TO_SEARCH SS
WHERE
CONTAINS(S.WHOLE_NAME,SS.FIRST_NAME)
OR CONTAINS(S.WHOLE_NAME,SS.LAST_NAME)
I need to search for the FIRST_NAME in table TABLE_TO_SEARCH, column WHOLE_NAME that has an full text index on it. It doesn't seem to be a valid query though... Is there any workaround to it by using the full text index search?
LATER EDIT:
Here is the business case: each night I am downloading from several websites information about "blacklisted" individuals and insert it into a table in this format: WholeName, LastName, FirstName, MiddleName. But the data is chaotic as WholeName does not necessarily contain either the last, first or middle name or the WholeName is null while the other 3 fields have values, or every of these 4 fields is null and so on. Also, the data may repeat itself as one blacklisted individual may come from 2+ of these websites. What I need to do is to compare this data, as chaotic as it is, against our customer data based on our customer's First and Last name and give it a matching score (rank) against the files we download from these websites.
First I tried with charindex or like operators but I couldn't create a scoring algorithm based on this and also it took 6 hours to compare just our customer's first and last name with only the WholeName column from the TABLE_TO_SEARCH table. I thought that perhaps implementing the full_text index it would get easier and faster but ... apparently I was wrong.
Has anyone dealt with a task like this? And if so, what was the best approach?
After skimming http://technet.microsoft.com/en-us/library/ms187787.aspx and http://technet.microsoft.com/en-us/library/ms142571.aspx I don't think it is possible to do your search in this way. Not only that, but it seems this type of index wouldn't work well with names anyway.
If you care about checking one name then all you have to do is set those values to variables. This method would allow you to use the full-text index.
Otherwise, I would suggest splitting the WHOLE_NAME column (if there is a space or unique character between the first and last name) and comparing each part to those other columns. If you are working with a huge data set, you may want to experiment with doing this at a temp table level and creating an index.
Good luck!
I have a drop down list of subjects. Two particular subjects are Mathematics and Additional Mathematics. When I choose Mathematics from the drop down list, records from Additional Mathematics and Mathematics are both displayed. Worse is that records from Additional Mathematics are shown first. Many colleagues made mistakes because of this.
How do I make the drop down list such that when clicked, the exact terms are used instead?
This is a problem that is not necessarily unique to FileMaker. You are searching for a name that is imprecise because it is a match for multiple names. Rather instead you might want to search for a unique key whose subject name is 'Mathematics' as displayed in your drop down. It is the use of that unique key that allows you to perform a precise search, even when the name of one subject is a partial or complete match for another.
This solution requires you to add a unique serial number which is, in your case, to alter the Subjects table and add a field called 'idnumber' or similar. The field type should be Number, and the options should include Auto-Enter-Serial number-Generate and On creation-increment by 1. The trick here lies in making sure no two subjects have the same 'idnumber' even when you aren't paying attention, so set the next value to something greater than the number of subjects that already exist. Then from another layout assign each existing subject a unique idnumber, noting that if there are a great many subjects you could script that step.
I should mention that many recommend a best practice of never changing a production layout, but rather to duplicate the layout and make the required changes to the duplicate. This minimizes the effects of testing your changes etc.
Finally, change your layout in inspector such that the drop down list shows Use values from field: 'idnumber'. Select Also display values from second field: 'Subject' and Show values only from second field. Now your drop down is the same clean selection as before. The field will not look correct yet because it will show a number. To make it look correct you can insert another field, selecting 'Subject'. Place that field over top of the 'idnumber' and send 'idnumber' to the back. Fill the 'Subject' field with the correct background solid color instead of none, and enjoy your new precision search capability! The entire process is handled server side so it should not matter that client access is IWP.
If you're using the selection to do a find, put an "==" before the text you're searching on. This will tell FileMaker to do an exact field contents search, instead of a "contains" search.