How to find a MoveTo destination filled by database? - database

I could need some help with a Anylogic Model.
Model (short): Manufacturing scenario with orders move in a individual route. The workplaces (WP) are dynamical created by simulation start. Their names, quantity and other parameters are stored in a database (excel Import). Also the orders are created according to an import. The Agent population "order" has a collection routing which contains the Workplaces it has to stop in the specific order.
Target: I want a moveTo block in main which finds the next destination of the agent order.
Problem and solution paths:
I set the destination Type to agent and in the Agent field I typed a function agent.getDestination(). This function is in order which returns the next entry of the collection WP destinationName = routing.get(i). With this I get a Datatype error (while run not compiling). I quess it's because the database does not save the entrys as WP Type but only String.
Is there a possiblity to create a collection with agents from an Excel?
After this I tried to use the same getDestination as String an so find via findFirst the WP matching the returned name and return it as WP. WP targetWP = findFirst(wps, w->w.name == destinationName);
Of corse wps (the population of Workplaces) couldn't be found.
How can I search the population?
Maybe with an Agentlink?
I think it is not that difficult but can't find an answer or a solution. As you can tell I'm a beginner... Hope the description is good an someone can help me or give me a hint :)
Thanks

Is there a possiblity to create a collection with agents from an Excel?
Not directly using the collection's properties and, as you've seen, you can't have database (DB) column types which are agent types.1
But this is relatively simple to do directly via Java code (and you can use the Insert Database Query wizard to construct the skeleton code for you).
After this I tried to use the same getDestination as String an so find via findFirst the WP matching the returned name and return it as WP
Yes, this is one approach. If your order details are in Excel/the database, they are presumably referring to workplaces via some String ID (which will be a parameter of the workplace agents you've created from a separate Excel worksheet/database table). You need to use the Java equals method to compare strings though, not == (which is for comparing numbers or whether two objects are the same object).
I want a moveTo block in main which finds the next destination of the agent order
So the general overall solution is
Create a population of Workplace agents (let's say called workplaces in Main) from the DB, each with a String parameter id or similar mapped from a DB column.
Create a population of Order agents (let's say called orders in Main) from the DB and then, in their on-startup action, set up their collection of workplace IDs (type ArrayList, element class String; let's say called workplaceIDsList) using data from another DB table.
Order probably also needs a working variable storing the next index in the list that it needs to go to (so let's say an int variable nextWorkplaceIndex which starts at 0).
Write a function in Main called getWorkplaceByID that has a single String argument id and returns a Workplace. This gets the workplace from the population that matches the ID; a one-line way similar to yours is findFirst(workplaces, w -> w.id.equals(id)).
The MoveTo block (which I presume is in Main) needs to move the Order to an agent defined by getWorkplaceByID(agent.workplaceIDsList.get(nextWorkplaceIndex++)). (The ++ bit increments the index after evaluating the expression so it is ready for the next workplace to go to.)
For populating the collection, you'd have two tables, something like the below (assuming using strings as IDs for workplaces and orders):
orders table: columns for parameters of your orders (including some String id column) other than the workplace-list. (Create one Order agent per row.)
order_workplaces table: columns order_id, sequence_num and workplace_id (so with multiple rows specifying the sequence of workplace IDs for an order ID).
In the On startup action of Order, set up the skeleton query code via the Insert Database Query wizard as below (where we want to loop through all rows for this order's ID and do something --- we'll change the skeleton code to add entries to the collection instead of just printing stuff via traceln like the skeleton code does).
Then we edit the skeleton code to look like the below. (Note we add an orderBy clause to the initial query so we ensure we get the rows in ascending sequence number order.)
List<Tuple> rows = selectFrom(order_workplaces)
.where(order_workplaces.order_id.eq(id))
.orderBy(order_workplaces.sequence_num.asc())
.list();
for (Tuple row : rows) {
workplaceIDsList.add(row.get(order_workplaces.workplace_id));
}
1 The AnyLogic database is a normal relational database --- HSQLDB in fact --- and databases only understand their own specific data types like VARCHAR, with AnyLogic and the libraries it uses translating these to Java types like String. In the user interface, AnyLogic makes it look like you set the column types as int, String, etc. but these are really the Java types that the columns' contents will ultimately be translated into.
AnyLogic does support columns which have option list types (and the special Code type column for columns containing executable Java code) but these are special cases using special logic under the covers to translate the column data (which is ultimately still a string of characters) into the appropriate option list instance or (for Code columns) into compiled-on-the-fly-and-then-executed Java).

Welcome to Stack Overflow :) To create a Population via Excel Import you have to create a method and call Code like this. You also need an empty Population.
int n = excelFile.getLastRowNum(YOUR_SHEET_NAME);
for(int i = FIRST_ROW; i <= n; i++){
String name = excelFile.getCellStringValue(YOUR_SHEET_NAME, i, 1);
double SEC_PARAMETER_TO_READ= excelFile.getCellNumericValue(YOUR_SHEET_NAME, i, 2);
WP workplace = add_wps(name, SEC_PARAMETER_TO_READ);
}
Now if you want to get a workplace by name, you have to create a method similar to your try.
Functionbody:
WP workplaceToFind = wps.findFirst(w -> w.name.equals(destinationName));
if(workplaceToFind != null){
//do what ever you want
}

Related

Avoiding database queries in Anylogic

I would like to avoid costly repeated data base queries in Anylogic. I have seen the following thread in Stack Overflow What is the fastest way to look up continuous data on Anylogic (Java, SQL) where a simple three step answer is provided but I'm not sure what the second point of the three actually means:
Save all rows as instances of that class at model start-up into a map - you can use Origin/Destination as the key (use Anylogic's Pair object) and the class instance as the value
I have created a class that takes as inputs the information from each column of my database. I would now like to save each row as an instance of that class - is there an easy way to do this? I may be missing something simple as I'm new to Anylogic.
I'm also unsure of how to create a mapping, if anyone could add more detail to point 2 above I'd be very grateful!
this is effectively the best advice, you created the class, which is a great step, but now, one element of that class, will be used as the key... for example the name... for instance if your class has firstName as one variable and lastName as another variable, you will use a string that is the concatenation of firstName and lastName as your key. Of course any key is fine, assuming that it is unique for all your table. Also an integer as an id is ok too.
create a collection of type LinkedHashMap
Create a class (you did that)
Your collection will take as the key a String (first + last name) and as the value of the elment the class...
now, when you read your database you will have something like this:
for(Tuple t : yourQueryResults){
YourClass yc=new YourClass(t.get(db.var1),t.get(db.var2));
String totalName=t.get(db.first_name)+"_"+t.get(db.last_name);
yourCollection.put(totalName,yc);
}
Now every time you want to find someone with the a name, for example "John Doe", instead of making a query, you will do
yourCollection.get("John_Doe").theVarYouWant;
if you use an id instead of the name, you can set an int as the key, and then you will just do yourCollection.get(theId).theVarYouWant

How to make dynamic references to tables in Anylogic?

I`ve modeled six machines. Each of them has a different profile of electricity load. The load profile is provided in a table in AnyLogic. Every machine has an own table storing these values. I iterate trough the values to implement the same in TableFunctions. Now I face the following challenge: How can I make a dynamic reference to the relevant table. I would like to pick a specific table in dependence of a machine indice. How can I define a variable that dynamically refers to the relevant table object?
Thank you for your help!
not sure it is really necessary in your case but here goes:
You can store a reference to a database table to a variable of the following type:
com.mysema.query.sql.RelationalPathBase
When selecting values of double (int, String, etc.) type in a particular column, you may get the column by index calling variable.getColumns().get(index). Then you need to cast it to the corresponding type like below:
List<Double> resultRows = selectFrom(variable).where(
( (com.mysema.query.types.path.NumberPath<Double>) variable.getColumns().get(1) ).eq(2.0))
.list(( (com.mysema.query.types.path.NumberPath<Double>) variable.getColumns().get(1) ));
Are you always going to have a finite number of machines and how is your load profile represented? If you have a finite number of machines, and the load profile is a set of individual values - or indeed as long as you can hold those values in a single field per element - then you can create a single table, e.g. machine_load_profile, where the first column is load_profile_element and holds element IDs and further columns are named machine_0, machine_1, machine_2 etc., holding the values for each load profile element. You can then get the load profile elements for a single machine like this:
List<Double> dblReturnLPEs = main.selectValues(
"SELECT machine_" + oMachine.getIndex()
+ " FROM machine_load_profile"
+ " ORDER BY load_profile_element;"
);
and either iterate that list or convert them into an array:
dblLPEValues = dblReturnLPEs.stream().mapToDouble(Double::doubleValue).toArray();
and iterate that.
Of course you could also use the opposite orientation for your columns and rows as well, using WHERE, I simply had a handy example oriented in this manner.

MS Access, use query name as field default value

My department uses a software tool that can use a custom component library sourced from Tables or Queries in an MS Access database.
Table: Components
ID: AutoNumber
Type: String
Mfg: String
P/N: String
...
Query: Resistors
SELECT Components.*
FROM Components
WHERE Components.Type = "Resistors"
Query: Capacitors
SELECT Components.*
FROM Components
WHERE Components.Type = "Capacitors"
These queries work fine for SELECT. But when users add a row to the query, how can I ensure the correct value is saved to the Type field?
Edit #2:
Nope, can't be done. Sorry.
Edit #1:
As was pointed out, I may have misunderstood the question. It's not a wonky question after all, but perhaps an easy one?
If you're asking how to add records to your table while making sure that, for example, "the record shows up in a Resistors query if it's a Resistor", then it's a regular append query, that specifies Resisitors as your Type.
For example:
INSERT INTO Components ( ID, Type, Mfg )
SELECT 123, 'Resistors', 'Company XYZ'
If you've already tried that and are having problems, it could be because you are using a Reserved Word as a field name which, although it may work sometimes, can cause problems in unexpected ways.
Type is a word that Access, SQL and VBA all use for a specific purpose. It's the same idea as if you used SELECT and FROM as field or table names. (SELECT SELECT FROM FROM).
Here is a list of reserved words that should generally be avoided. (I realize it's labelled Access 2007 but the list is very similar, and it's surprisingly difficult to find an recent 'official' list for Excel VBA.)
Original Answer:
That's kind a a wonky way to do things. The point of databases is to organize in such a way as to prevent duplication of not only data, but queries and codes as well
I made up the programming rule for my own use "If you're doing anything more than once, you're doing it wrong." (That's not true in all cases but a general rule of thumb nonetheless.)
Are the only options "Resistors" and "Capacitors"? (...I hope you're not tracking the inventory of an electronics supply store...) If there are may options, that's even more reason to find an alternative method.
To answer your question, in the Query Design window, it is not possible to return the name of the open query.
Some alternative options:
As #Erik suggested, constrain to a control on a form. Perhaps have a drop-down or option buttons which the user can select the relevant type. Then your query would look like:
SELECT * FROM Components WHERE Type = 'Forms![YourFormName]![NameOfYourControl]'
In VBA, have the query refer to the value of a variable, foe example:
Dim TypeToDel as String
TypeToDel = "Resistor"
DoCmd.RunSQL "SELECT * FROM Components WHERE Type = '" & typeToDel'"
Not recommended, but you could have the user manually enter the criteria. If your query is like this:
SELECT * FROM Components WHERE Type = '[Enter the component type]'
...then each time the query is run, it will prompt:
Similarly, you could have the query prompt for an option, perhaps a single-digit or a code, and have the query choose the the appropriate criteria:
...and have an IF statement in the query criteria.
SELECT *
FROM Components
WHERE Type = IIf([Enter 1 for Resistors, 2 for Capacitors, 3 for sharks with frickin' laser beams attached to their heads]=1,'Resistors',IIf([Enter 1 for Resistors, 2 for Capacitors, 3 for sharks with frickin' laser beams attached to their heads]=2,'Capacitors','LaserSharks'));
Note that if you're going to have more than 2 options, you'll need to have the parameter box more than once, and they must be spelled identically.
Lastly, if you're still going to take the route of a separate query for each component type, as long as you're making separate queries anyway, why not just put a static value in each one (just like your example):
SELECT * FROM Components WHERE Type = 'Resistor'
There's another wonky answer here but that's just creating even more duplicate information (and more future mistakes).
Side note: Type is a reserved word in Access & VBA; you might be best to choose another. (I usually prefix with a related letter like cType.)
More Information:
Use parameters in queries, forms, and reports
Use parameters to ask for input when running a query
Microsoft Access Tips & Tricks: Parameter Queries
 • Frickin' Lasers

Django Query Optimisation

I am working currently on telecom analytics project and newbie in query optimisation. To show result in browser it takes a full minute while just 45,000 records are to be accessed. Could you please suggest on ways to reduce time for showing results.
I wrote following query to find call-duration of a person of age-group:
sigma=0
popn=len(Demo.objects.filter(age_group=age))
card_list=[Demo.objects.filter(age_group=age)[i].card_no
for i in range(popn)]
for card in card_list:
dic=Fact_table.objects.filter(card_no=card.aggregate(Sum('duration'))
sigma+=dic['duration__sum']
avgDur=sigma/popn
Above code is within for loop to iterate over age-groups.
Model is as follows:
class Demo(models.Model):
card_no=models.CharField(max_length=20,primary_key=True)
gender=models.IntegerField()
age=models.IntegerField()
age_group=models.IntegerField()
class Fact_table(models.Model):
pri_key=models.BigIntegerField(primary_key=True)
card_no=models.CharField(max_length=20)
duration=models.IntegerField()
time_8bit=models.CharField(max_length=8)
time_of_day=models.IntegerField()
isBusinessHr=models.IntegerField()
Day_of_week=models.IntegerField()
Day=models.IntegerField()
Thanks
Try that:
sigma=0
demo_by_age = Demo.objects.filter(age_group=age);
popn=demo_by_age.count() #One
card_list = demo_by_age.values_list('card_no', flat=True) # Two
dic = Fact_table.objects.filter(card_no__in=card_list).aggregate(Sum('duration') #Three
sigma = dic['duration__sum']
avgDur=sigma/popn
A statement like card_list=[Demo.objects.filter(age_group=age)[i].card_no for i in range(popn)] will generate popn seperate queries and database hits. The query in the for-loop will also hit the database popn times. As a general rule, you should try to minimize the amount of queries you use, and you should only select the records you need.
With a few adjustments to your code this can be done in just one query.
There's generally no need to manually specify a primary_key, and in all but some very specific cases it's even better not to define any. Django automatically adds an indexed, auto-incremental primary key field. If you need the card_no field as a unique field, and you need to find rows based on this field, use this:
class Demo(models.Model):
card_no = models.SlugField(max_length=20, unique=True)
...
SlugField automatically adds a database index to the column, essentially making selections by this field as fast as when it is a primary key. This still allows other ways to access the table, e.g. foreign keys (as I'll explain in my next point), to use the (slightly) faster integer field specified by Django, and will ease the use of the model in Django.
If you need to relate an object to an object in another table, use models.ForeignKey. Django gives you a whole set of new functionality that not only makes it easier to use the models, it also makes a lot of queries faster by using JOIN clauses in the SQL query. So for you example:
class Fact_table(models.Model):
card = models.ForeignKey(Demo, related_name='facts')
...
The related_name fields allows you to access all Fact_table objects related to a Demo instance by using instance.facts in Django. (See https://docs.djangoproject.com/en/dev/ref/models/fields/#module-django.db.models.fields.related)
With these two changes, your query (including the loop over the different age_groups) can be changed into a blazing-fast one-hit query giving you the average duration of calls made by each age_group:
age_groups = Demo.objects.values('age_group').annotate(duration_avg=Avg('facts__duration'))
for group in age_groups:
print "Age group: %s - Average duration: %s" % group['age_group'], group['duration_avg']
.values('age_group') selects just the age_group field from the Demo's database table. .annotate(duration_avg=Avg('facts__duration')) takes every unique result from values (thus each unique age_group), and for each unique result will fetch all Fact_table objects related to any Demo object within that age_group, and calculate the average of all the duration fields - all in a single query.

MDX MEMBER causing NON EMPTY to not filter

I'm using an MDX query to pull information to support a set of reports. A high degree of detail is required for the reports so they take some time to generate. To speed up the access time we pull the data we need and store it in a flat Oracle table and then connect to the table in Excel. This makes the reports refresh in seconds instead of minutes.
Previously the MDX was generated and run by department for 100 departments and then for a number of other filters. All this was done in VB.Net. The requirements for filters have grown to the point where this method is not sustainable (and probably isn't the best approach regardless).
I've built the entire dataset into one MDX query that works perfectly. One of my sets that I cross join includes members from three different levels of hierarchy, it looks like this:
(
Descendants([Merch].[Merch CHQ].[All], 2),
Descendants([Merch].[Merch CHQ].[All], 3),
[Merch].[Merch CHQ].[Department].&[1].Children
)
The problem for me is in our hierarchy (which I can't change), each group (first item) and each department (second item) have the same structure to their naming, ie 15-DeptName and it's confusing to work with.
To address it I added a member:
MEMBER
[Measures].[Merch Level] AS
(
[Merch].[Merch CHQ].CurrentMember.Level.Name
)
Which returns what type the member is and it works perfectly.
The problem is that it updates for every member so none of the rows get filtered by NON BLANK, instead of 65k rows I have 130k rows which will hurt my access performance.
Can my query be altered to still filter out the non blanks short of using IIF to check each measurement for null?
You can specify Null for your member based on your main measure like:
MEMBER
[Measures].[Merch Level] AS
IIf(IsEmpty([Measures].[Normal Measure]),null,[Merch].[Merch CHQ].CurrentMember.Level.Name)
That way it will only generate when there is data. You can go further and add additional dimensions to the empty check if you need to get more precise.

Resources