I am trying to get multiple employee dependents to be on the same row of data on my output file. I can get one dependent on the employee's row, but not more than one.
I tried using a Left Join where I am joining the AutoNum so it matches with employees and dependents, but I still am only pulling one dependent.
Any ideas on how to get all needed data on one row in a SQL Access query?
SELECT E.FirstName, E.LastName, E.SSN,
Switch(E.MemberStartDate<="2018-01-01" And E.MemberEndDate>="2018-12-31","X") AS Cov12Months,
D.DepFirstName, D.DepLastName, D.ResponsibleIndividualSSN, D.CoveredIndividualSSN, D.DepDOB,
Switch(D.DepStartDate<="2018-01-01" And D.DepEndDate>="2018-12-31","X") AS DCov12Months,
FROM EMP_Test AS E LEFT JOIN Dep_Test AS D ON E.AutoNum = D.AutoNum;
Below is a sample image of what my results are currently. As you can see, Charles Soper's record is correct since he only has one dependent. But Susan Smith has two records because she has two dependents. I need both dependents on one row
A VBA method is one approach and examples provided in comment link. A CROSSTAB is also a possibility. Each approach has its pros and cons.
Consider:
TRANSFORM Max([DepFirstName] & " " & [DepLastName]) AS DepName
SELECT EmpDeps.EmpID
FROM EmpDeps
GROUP BY EmpDeps.EmpID
PIVOT DCount("*","EmpDeps","EmpID='" & [EmpID] & "' AND ID<" & [ID])+1 In (1,2,3,4,5,6,7,8,9,10);
This requires a unique identifier field in table - autonumber should serve.
Defining column names in PIVOT clause allows query to be stable enough to use as report RecordSource. This query can be joined to Employees table to retrieve additional employee info.
Related
so I've been struggling with some of the select statements on multiple tables:
Employee table
Employee_ID
First_Name
Last_Name
Assignment table
Assignment_ID
Employee_ID
Host_Country_arrival_Date
Host_Country_departure_Date
Scheduled_End_Date
I'm being asked to display query to display employee full name, number of days between the host country arrival date and host country departure date, number of days between today's date and the assignment scheduled end date and the results sorted according to host country arrival date with the oldest date on top.
also, I'm not familiar with the sort function in SQL server..
Here's my query and I've been getting syntax errors:
SELECT
First_Name
Last_Name
FROM Employee
SELECT
Host_Country_Arrival_Date
Host_Country_Departure_Date
FROM Assignment;
So, Basically what your code is doing is 2 different queries. The first getting all the employees names, and the second one getting the dates of the assignments.
What you'll want to do here is take advantage of the relationship between the tables using a JOIN. That is basically saying "Give me all employees and all of HIS/HERS assignments". So, for each assignment that the employee has, it will bring a row in the result with his name and the assignment info.
To get the difference between days you use DATEDIFF passing 3 parameters, the timespan in which to calculate the difference, the first and the second date. It will then Subtract the first one from the second one and give you the result in the selected timespan.
And finnaly the sorting: Just add 'ORDER BY' followed by each column that you want to use for ordering and then specify if you want it ascending (ASC) or descending (DESC).
You can check how I would answer the if that question was proposed to me in a coding challenge.
SELECT
CONCAT(E.First_Name,' ', E.Last_Name) FullName,
DATEDIFF(DAY,Scheduled_End_Date,getdate()) DaysTillScheduledDate,
DATEDIFF(DAY,Host_Country_Arrival_Date,Host_Country_Departure_Date) DaysTillScheduledDate
FROM Employee As E --Is nice to add aliases
Inner Join
Assignment As A
on E.Employee_ID = A.Employee_ID -- Read a little bit about joins, there are a lot of material availabel an its going to be really necessary moving forward with SQL
order by Host_Country_Arrival_Date DESC -- Just put the field that you want to order by here, desc indicates that it should be descending
You should use a JOIN to link the tables together on Employee_ID:
SELECT
First_Name,
Last_Name,
Host_Country_Arrival_Date,
Host_Country_Departure_Date
FROM Employee
JOIN Assignment ON Assignment.Employee_ID = Employee.Employee_ID;
What this is saying basically is that for each employee, go out to the assignments table and add the assignments for that employee. If there are multiple assignments, the employee columns will be repeated on each row with the assignment columns for the assignment.
You need to look for the join and group by. Please find this link for reference tutorial
For now you may try this...
SELECT
CONCAT(Emp.First_Name,' ', Emp.Last_Name) FullName,
DATEDIFF(DAY,Scheduled_End_Date,getdate()) DaysTillScheduledDate,
DATEDIFF(DAY,Host_Country_Arrival_Date,Host_Country_Departure_Date) DaysTillScheduledDate
FROM Employee As Emp Inner Join Assignment As Assign on Emp.Employee_ID = Assign.Employee_ID
order by Host_Country_Arrival_Date DESC
I am still learning the ropes of SQL so I have run into my first obstacle. I am to create an SQL query that retrieves employee.firstname, employee.lastname, dependents.depname, and dependents.birthday from the two tables employees and dependents.
I am only supposed to show an employee if he or she has a dependent.
My primary table (employee; only the first 43 rows): employee table
My secondary table (dependents): dependents table
This is what I have so far:
SELECT
employee.firstname, employee.lastname,
dependents.depname, dependents.birthday
FROM
employee
INNER JOIN
dependents ON employee.id = dependents.empid
This works fine however I run into many duplicate rows of data:
Original Query
This is not the full query result but I think it provides sufficient evidence of my problem.
I used the DISTINCT keyword with my SELECT statement, but it only retrieved a small number of my dependents.
Adding DISTINCT
Have you already any duplicates in one of the tables employee or dependents? The second result looks correct. With select distinct the database removes all duplicates from the result set.
I have two tables in a Database
and
I need to retrieve the number of staff per manager in the following format
I've been trying to adapt an answer to another question
SELECT bankNo AS "Bank Number",
COUNT (*) AS "Total Branches"
FROM BankBranch
GROUP BY bankNo
As
SELECT COUNT (*) AS StaffCount ,
Employee.Name AS Name
FROM Employee, Stafflink
GROUP BY Name
As I look at the Group BY I'm thinking I should be grouping by The ManID in the Stafflink Table.
My output with this query looks like this
So it is counting correctly but as you can see it's far off the output I need to get.
Any advice would be appreciated.
You need to join the Employee and Stafflink tables. It appears that your FROM clause should look like this:
FROM Employee INNER JOIN StaffLink ON Employee.ID = StaffLink.ManID
You have to join the Eployee table twice to get the summary of employees under manager
select count(*) as StaffCount,Manager.Name
from Employee join Stafflink on employee.Id = StaffLink.EmpId
join Employee as Manager on StaffLink.ManId = Manager.Id
Group by Manager.Name
The answers that advise you on how to join are correct, assuming that you want to learn how to use SQL in MS Access. But there is a way to accomplish the same thing using the ACCESS GUI for designing queries, and this involves a shorter learning curve than learning SQL.
The key to using the GUI when more than one table is involved is to realize that you have to define the relationships between tables in the relationship manager. Once you do that, designing the query you are after is a piece of cake, just point and click.
The tricky thing in your case is that there are two relationships between the two tables. One relationship links EmpId to ID and the other links ManId to ID.
If, however, you want to learn SQL, then this shortcut will be a digression.
If you don't specify a join between the tables, a so called Cartesian product will be built, i.e., each record from one table will be paired with every record from the other table. If you have 7 records in one table and 10 in the other you will get 70 pairs (i.e. rows) before grouping. This explains why you are getting a count of 7 per manager name.
Besides joining the tables, I would suggest you to group on the manager id instead of the manager name. The manager id is known to be unique per manager, but not the name. This then requires you to either group on the name in addition, because the name is in the select list or to apply an aggregate function on the name. Each additional grouping slows down the query; therefore I prefer the aggregate function.
SELECT
COUNT(*) AS StaffCount,
FIRST(Manager.Name) AS ManagerName
FROM
Stafflink
INNER JOIN Employee AS Manager
ON StaffLink.ManId = Manager.Id
GROUP BY
StaffLink.ManId
I don't know if it makes a performance difference, but I prefer to group on StaffLink.ManId than on Employee.Id, since StaffLink is the main table here and Employee is just used as lookup table in this query.
I have a staff database table containing staff members, with user_no and user_name columns. I have another, department, table containing the departments which staff can be members of, with dept_no and dept_name as columns.
Because staff can be members of multiple departments, I have a third, staff_dept, table with a user_no column and a dept_no column, which are the primary keys of those other two tables. This table shows which departments each member of staff belongs to and contains one row for each user/department intersection.
I would like to have an output in the form of a spreadsheet (CSV file, whatever; I'll be fine mangling the results into a usable form after I've got them) with one column for each department, and one row for each user, with an X appearing at each intersection, as defined in staff_dept.
Can I write a single SQL query which will achieve this result? or will I have to do some "real" programming (because it's not a "real" program until you've nested three or four for loops, obviously) to collect and format this data?
This can be done with a PIVOT table (using SQL Server):
SELECT user_name, [dept1name], [dept2name], [dept3name], ...
FROM
(SELECT s.user_name, d.dept_name,
case when sd.user_no is not null then 'X' else '' end as matches
from staff s
cross join department d
left join staff_dept sd on s.user_no = sd.user_no and d.dept_no = sd.dept_no
) AS s
PIVOT
(
min(matches)
FOR dept_name IN ([dept1name], [dept2name], [dept3name], ...)
) AS pvt
order by user_name
Demo: http://www.sqlfiddle.com/#!3/c136d/5
Edit: To generate the PIVOT query dynamically from the list of departments in the table, you would make use of dynamic SQL, i.e., generate the code into a variable and use sp_executesql helper stored procedure. Here's an example: http://www.sqlfiddle.com/#!3/c136d/14
In SQL Server (if you're using SQL Server), I would start with a full outer join (to include all staff and departments, not just those involved in the relation), drop that into a pivot statement to pivot all departments into columns, and then build a short script to generate and dynamically execute that SELECT statement (because the columns created by a pivot statement must be hard-coded, they can't be dynamically generated at run time).
Here's a sample -- it's an unpivot statement, but the concept is pretty much the same.
I was asked the below SQL question in an interview. Kindly explain how it works and what join it is.
Q: There are two tables: table emp contains 10 rows and table department contains 12 rows.
Select * from emp,department;
What is the result and what join it is?
It would return the Cartesian Product of the two tables, meaning that every combination of emp and department would be included in the result.
I believe that the next question would be:
Blockquote
How do you show the correct department for each employee?
That is, show only the combination of emp and department where the employee belongs to the department.
This can be done by:
SELECT * FROM emp LEFT JOIN department ON emp.department_id=department.id;
Assuming that emp has a field called department_id, and department has a matching id field (This is quite standard in these type of questions).
The LEFT JOIN means that all items from the left side (emp) will be included, and each employee will be matched with the corresponding department. If no matching department is found, the resulting fields from departments will remain empty. Note that exactly 10 rows will be returned.
To show only the employees with valid department IDs, use JOIN instead of LEFT JOIN. This query will return 0 to 10 rows, depending on the number of matching department ids.
The join you specified is a cross join. It will produce one row for each combination of records in the tables being joined.
I'll let you do the math from there.
This will do a cross join I believe, returning 120 rows. One row for each pair-wise combination of rows from each of the two tables.
All-in-all a fairly useless join most of the time.
You will get all rows from both tables with each row joined together.
This is known as a Cartesian join and is very bad.
You will get a total of 120 rows.
This is also the old implied syntax (18 yeasr out of date) and accidental cross joins are a common problem with this syntax. One should never use it. Explict joins are a better choice. I would have also mentioned this in an interview and explained why. I also would not have taken the job if they actually used crappy syntax like this because it's very use shows me the database is very likely to be poorly designed.