I want to write a query to update a table based on below:
Let's say we have below table
Name |Account |Currency |Balance |
Sahil |Account1 |USD |40,000 |
Rohan |Account2 |USD |30,000 |
Mohit |Account3 |USD |20,000 |
Ronak |Account4 |USD |10,000 |
John |Account5 |EUR |50,000 |
Ram |Account6 |EUR |40,000 |
I want to deduct a total of $90,000. Firstly, I will deduct only from accounts having currency as USD because the amount which I want to deduct is in USD. Secondly, the way i want to deduct is start from the account which has the highest amount.
In my example I start with account1 and deduct 40,000 and so on and so forth. After deduction, as per the example, I should have exhausted amounts in all of the accounts except account4. The table after deduction will look like below:
Name |Account |Currency |Balance |
Sahil |Account1 |USD | 0 |
Rohan |Account2 |USD | 0 |
Mohit |Account3 |USD | 0 |
Ronak |Account4 |USD |10,000 |
John |Account5 |EUR |50,000 |
Ram |Account6 |EUR |40,000 |
Same goes for Euro.
Is it possible to write a generic query where currency is my key without cursor?
I don't want hardcode currency in my query.
Using Sybase ASE which does not support lead and lag or any advanced feature. Is it possible with basic query?
Related
My question is a bit simple, there are many answers to it but I have a question more about the query itself for certain conditions.
I have a table like this :
Client | Date | Employee | Last Record | Trained
JOE | April 2020 | John Doe | May 2019 | TRUE
JOE |February 2020| John Doe | May 2019 | TRUE
JOE | May 2 019 | John Doe | May 2019 | FALSE
Now I watn to make a simple SQL summary table saying :
Client | Date | Inactive | Trained
JOE | April 2020 | 1 | 1
JOE |February 2020 | 1 | 1
JOE | May 2019 | 0 | 0
So basically do a count of Employees grouped by client and date, with the condition that the difference of date and last record is greater than, lets say 1 month and also in another column count the number of employees with a TRUE condition.
So my question is basically that, hwo would I go about creating a summary table where I want to set conditions per column, such as a date difference or if its true in a column.
Before you say Use a view, I need to create this table for performance reason since I am querying the first table which has millions of rows for a report program. However it is simple and better to query instead a table that holds a summary or counts with conditions.
Temporal tables and time periods are nothing special in the IT world. But somehow it seems my request is rather unique because I cannot find anything useful for it at all.
What I have are two tables, one containing static data and the other one dynamic data for entries of the first table which changes over time. For each row in the second table there are two columns ValidFrom and ValidUntil whereas the latter can be null if there is no planned end of validity.
Simplified, the schema looks like this:
tbStatic
+----+------------+------------+
| Id | Attribute1 | Attribute2 |
+----+------------+------------+
| 1 | foo | bar |
| 2 | baz | foo |
+----+------------+------------+
tbDynamic
+----+------------+---------------------+---------------------+------------+------------+
| Id | tbStaticId | ValidFrom | ValidUntil | Attribute1 | Attribute2 |
+----+------------+---------------------+---------------------+------------+------------+
| 1 | 1 | 2018-01-01 00:00:00 | 2018-01-31 23:59:59 | 1 | 0 |
| 2 | 2 | 2018-04-01 00:00:00 | 2018-04-02 11:59.59 | 2 | 1 |
| 3 | 1 | 2018-02-01 00:00:00 | null | 2 | 1 |
| 4 | 2 | 2018-05-01 00:00:00 | 2018-06-01 00:00:00 | 23 | 15 |
| 5 | 2 | 2018-07-01 01:23:45 | 2018-07-05 23:12:01 | 80 | 12 |
+----+------------+---------------------+---------------------+------------+------------+
As you might have spotted, there is the possibility that we have holes between time periods. What we cannot have is overlapping periods, though. This means it is impossible to have overlapping time periods for the same tbStaticId.
Unfortunately, this is only a requirement until now and although it is enforced in the application using the database, I would prefer having a constraint on the table that prevents new rows to be inserted or existing rows to be updated when they violate this time uniqueness.
As stated, my research up to this point was rather disappointing and that is also the reason I cannot really show any code I've tried yet. The most promising approach I followed yet was to create a function that takes a record or the two time period values and the foreign key as input and determines if they overlap with something else. This function could then be called in a check constraint. But after thinking about the amount of cases to check, I gave up because it seemed unreasonable (especially when considering updates as well, which require additional attention).
So my question is if there is some easy way to constraint time slices in SQL Server, without the use of temporal tables (not available in my SQL Server version)? And if yes, how?
There are few payment methods: credit/debit card, cash, bitcoin
This is my payment transaction table:
Transaction:
| ID | AMOUNT | METHOD |
| 1 | 80 | credit |
| 2 | 100 | cash |
Transaction_credit:
| ID | AMOUNT | TYPE | TRANSACTION_ID |
| 1 | 80 | sale | 1 |
| 2 | -80 | reversal | 1 |
Transaction_cash:
| ID | AMOUNT | TYPE | TRANSACTION_ID |
| 2 | 100 | payment | 2 |
| 2 | -100 | refund | 2 |
Do you think it is a good idea to have amount in card, cash, and bitcoin sub table?
How can I solve the duplicate amount in sub table?
I think your database design needs some improvements.
Firstly: Transaction Entity (Table) in Accounting Systems holds all money transactions. If your sales are reversal, you should make a new Transaction row too. Also, if your Payment refunded, you should make a new Transaction row too.
Secondly: Details of all transactions should be saved in second level Entities (Tables). (as you design correctly). Transaction types (e.g. Card, Cash, Bitcoin and etc.) have many different attributes. So putting all types in one entity, make some bad design traps like Nullification.
Thirdly: If you want to have a complete Accounting System to supports all accounting parts (like generating Balance Sheet), you should add many other entities.
But in this case, you should hold Amount in Transaction. Fining Amount in other tables is so difficult when you want to perform some queries based on overall Amount on Transaction.
I am pretty new to database development and architecture. My only experience has been in college and now my project requires me to use that knowledge, however my project seems a lot more complicated with many more intricacies than what I studied.
A brief overview: My task is to basically turn paper work that was previously done by hand, into a quick computer application, which I will do in Java but thats far off now. I know I will need a database set up to accomplish my task since these reports are frequently edited. The report is a Labor Report. Basically, it shows who was working on a specific job, what days and how many hours on those days, as well as their total hours, pay rate, and total amount.
I believe my current problem lies within the fact that it seems like I'm going to have several "many to many" relationships, perhaps even nested, which is what is throwing my head for a spin as I try to organize information into entity relationship diagrams and tables. (I know that there are normally much more measured and organized stages to development but I don't have that experience and I'm essentially a one man team on this)
Contract Personnel with be selected out of a pool of Employees.
A Labor Contract can have 1 to 10 personnel (For sake of space on the final printed version, jobs requiring more laborers will have another Labor Contract.)
Each personnel must have 1 Title (foreman, mechanic, etc.) These titles can change from job to job. Joe Smith can be a mechanic on job A but a foreman on job B.
Each personnel must also have on record the number of hours they worked on each day of the week; and may have overtime and double overtime. (One Labor Record per week).
I am trying to avoid repeated data, or at least keep it to a minimum but I am struggling on figuring out how to do that in this situation. The tricky thing, at least in my mind, is figuring out how to handle the fact that different employees can work several jobs at once, under different titles, and different pay rates, and recording different types of hours (straight time, OT, double OT) on each day of the week.
Can anyone make suggestions?
I hope that I have supplied adequate information and apologize if I didn't or wasn't detailed enough. Please remember to keep in mind I'm a newbie to this type of work.
First thing, take a deep breath! It looks to me like you have a pretty good handle on this, maybe more than you think! This is not at all to try and design your project, and I'm sure you'll have lots of details to deal with, but maybe this will give an idea of how you might face these many many-to-many relationships swimming around in your head.
EMPLOYEES
---------
emp_id
emp_name
emp_address
JOBS
----
job_id
job_description
EMPLOYEE_JOBS
-------------
ej_id -- primary key
emp_id -- fk to employees table
job_id -- fk to jobs table
ej_title -- employee title for this job
ej_rate -- employee pay rate for this job
EMPLOYEE_JOB_HOURS
------------------
ejh_id -- primary key
ej_id -- fk to employee_jobs table
ejh_date
ejh_normal_hours -- hours worked by the employee on this job on this date, etc.
ejh_overtime_hours
ejh_double_overtime_hours
Following is a basic outline you could use to get started. Your final solution will be different based on your exact needs.
You'll need a table to store contract information. My example just shows a description but I'm sure you'll have much more than that.
contracts
id unsigned int(P)
description varchar(50)
+----+-------------+
| id | description |
+----+-------------+
| 1 | Contract A |
| 2 | Contract B |
| .. | ........... |
+----+-------------+
You'll need a table that links contracts and employees and shows what title the employee has for the given contract. In my example you can see that for Contract A John Q Public is a Foreman and Mary Jane Smith is a Mechanic. For Contract B their titles are reversed, John is a Mechanic and Mary is a Foreman. contract_id and employee_id are foreign keys to their respective tables and together they form the primary key. If it's possible that John and Mary get paid different rates for the same title (for example John get 25.00/hour as Foreman while Mary gets 20.00/hour) you would add a column here instead of using the rate in the titles table.
contracts_employees
contract_id unsigned int(F contracts.id)--\_(P)
employee_id unsigned int(F employees.id)--/
title_id varchar(15)(F titles.id)
+-------------+-------------+----------+
| contract_id | employee_id | title_id |
+-------------+-------------+----------+
| 1 | 1 | Foreman |
| 1 | 2 | Mechanic |
| 2 | 1 | Mechanic |
| 2 | 2 | Foreman |
| ........... | ........... | ........ |
+-------------+-------------+----------+
You'll need a table for employees (you could call this personnel if you prefer). You'll probably store a lot more than just their names...
employees
id unsigned int(P)
first_name varchar(30)
middle_name varchar(30)
last_name varchar(30)
...
+----+------------+-------------+-----------+-----+
| id | first_name | middle_name | last_name | ... |
+----+------------+-------------+-----------+-----+
| 1 | John | Quincy | Public | ... |
| 2 | Mary | Jane | Smith | ... |
| .. | .......... | ........... | ......... | ... |
+----+------------+-------------+-----------+-----+
You'll need a table to track hours worked. I just store a beginning and ending date/time, leaving it up to the application to calculate elapsed time. Your application will also need to ensure there is no overlap for employees - an employee should not be able to be working on more than one contract at any given time. Calculation of overtime and double overtime hours is also up to your application. If an employee's pay rate can change at any time (ie in the middle of a contract) you would want to store the pay rate in this table instead of using the rate from contracts_employees or titles.
hours
id unsigned int(P)
contract_id unsigned int(F contracts.id)
employee_id unsigned int(F employees.id)
beg datetime
end datetime
+----+-------------+-------------+---------------------+---------------------+
| id | contract_id | employee_id | beg | end |
+----+-------------+-------------+---------------------+---------------------+
| 1 | 1 | 1 | 2014-01-01 08:00:00 | 2014-01-01 17:00:00 |
| 2 | 1 | 2 | 2014-01-01 09:00:00 | 2014-01-01 17:30:00 |
| 3 | 1 | 1 | 2014-01-02 09:00:00 | 2014-01-02 10:00:00 |
| 4 | 1 | 2 | 2014-01-02 08:00:00 | 2014-01-02 09:00:00 |
| 5 | 2 | 1 | 2014-01-02 10:00:00 | 2014-01-02 17:30:00 |
| 6 | 2 | 2 | 2014-01-02 09:00:00 | 2014-01-02 15:00:00 |
| .. | ........... | ........... | ................... | ................... |
+----+-------------+-------------+---------------------+---------------------+
And finally a table to store titles and their related pay rates. If employees can be paid different rates for the same title, you wouldn't need the rate column here, instead you would use the rate stored in the contracts_employees table.
titles
id varchar(15)(P)
rate double
+----------+-------+
| id | rate |
+----------+-------+
| Foreman | 20.00 |
| Mechanic | 15.00 |
| ........ | ..... |
+----------+-------+
I need to regularly import large (hundreds of thousands of lines) tsv files into multiple related SQL Server 2008 R2 tables.
The input file looks something like this (it's actually even more complex and the data is of a different nature, but what I have here is analogous):
January_1_Lunch.tsv
+-------+----------+-------------+---------+
| Diner | Beverage | Food | Dessert |
+-------+----------+-------------+---------+
| Nancy | coffee | salad_steak | pie |
| Joe | milk | soup_steak | cake |
| Pat | coffee | soup_tofu | pie |
+-------+----------+-------------+---------+
Notice that one column contains a character-delimited list that needs preprocessing to split it up.
The schema is highly normalized -- each record has multiple many-to-many foreign key relationships. Nothing too unusual here...
Meals
+----+-----------------+
| id | name |
+----+-----------------+
| 1 | January_1_Lunch |
+----+-----------------+
Beverages
+----+--------+
| id | name |
+----+--------+
| 1 | coffee |
| 2 | milk |
+----+--------+
Food
+----+-------+
| id | name |
+----+-------+
| 1 | salad |
| 2 | soup |
| 3 | steak |
| 4 | tofu |
+----+-------+
Desserts
+----+------+
| id | name |
+----+------+
| 1 | pie |
| 2 | cake |
+----+------+
Each input column is ultimately destined for a separate table.
This might seem an unnecessarily complex schema -- why not just have a single table that matches the input? But consider that a diner may come into the restaurant and order only a drink or a dessert, in which case there would be many null rows. Considering that this DB will ultimately store hundreds of millions of records, that seems like a poor use of storage. I also want to be able to generate reports for just beverages, just desserts, etc., and I figure those will perform much better with separate tables.
The orders are tracked in relationship tables like this:
BeverageOrders
+--------+---------+------------+
| mealId | dinerId | beverageId |
+--------+---------+------------+
| 1 | 1 | 1 |
| 1 | 2 | 2 |
| 1 | 3 | 1 |
+--------+---------+------------+
FoodOrders
+--------+---------+--------+
| mealId | dinerId | foodId |
+--------+---------+--------+
| 1 | 1 | 1 |
| 1 | 1 | 3 |
| 1 | 2 | 2 |
| 1 | 2 | 3 |
| 1 | 3 | 2 |
| 1 | 3 | 4 |
+--------+---------+--------+
DessertOrders
+--------+---------+-----------+
| mealId | dinerId | dessertId |
+--------+---------+-----------+
| 1 | 1 | 1 |
| 1 | 2 | 2 |
| 1 | 3 | 1 |
+--------+---------+-----------+
Note that there are more records for Food because the input contained those nasty little lists that were split into multiple records. This is another reason it helps to have separate tables.
So the question is, what's the most efficient way to get the data from the file into the schema you see above?
Approaches I've considered:
Parse the tsv file line-by-line, performing the inserts as I go. Whether using an ORM or not, this seems like a lot of trips to the database and would be very slow.
Parse the tsv file to data structures in memory, or multiple files on disk, that correspond to the schema. Then use SqlBulkCopy to import each one. While it's fewer transactions, it seems more expensive than simply performing lots of inserts, due to having to either cache a lot of data or perform many writes to disk.
Per How do I bulk insert two datatables that have an Identity relationship and Best practices for inserting/updating large amount of data in SQL Server 2008, import the tsv file into a staging table, then merge into the schema, using DB functions to do the preprocessing. This seems like the best option, but I'd think the validation and preprocessing could be done more efficiently in C# or really anything else.
Are there any other possibilities out there?
The schema is still under development so I can revise it if that ends up being the sticking point.
You can import you file in the table of the following structure: Diner, Beverage, Food, Dessert, ID (identity, primary key NOT CLUSTERED - for performance issues).
After this simply add the following columns: Dinner_ID, Beverage_ID, Dessert_ID and fill them according to your separate tables (it's simple to group each of the columns and to add the missing data to lookup tables as Beverages, Desserts, Meals and, after this, to fix the imported table with the IDs for existent and newly added records).
The situation with Food table is more complex because of ability to combine the foods, but the same trick can be used: you can also add the data to your lookup table and, among this, store the combinations of foods in the additional temp table (with the unique ID) and separation on the single dishes.
When the parcing will be finished, you will have 3 temp tables:
table with all your imported data and IDs for all text columns
table with distinct food lists (with IDs)
table with IDs of food per food combination
From the above tables you can perform the insertion of the parsed values to either structure as you want.
In this case only 1 insert (bulk) will be done to the DB from the code side. All other data manipulations will be performed in the DB.