I have a database table has four columns called "Courses(CourseID,CourseName,CreditHours,LabSession)", and I wanna write SQL Statement that retrieve all data in the Course table, furthermore, the SQL must repeat the row (record) if the LabSession column in the row has a value "Y" otherwise retrieve the row as it is without repeating.
BTW, I am using Microsoft SQL Server Database
select CourseID,CourseName,CreditHours,LabSession from Courses
union ALL
select CourseID,CourseName,CreditHours,LabSession from Courses where LabSession='Y'
order by CourseID
SELECT CourseID, CourseName, CreditHours, LabSession
FROM Courses
UNION ALL
SELECT CourseID, CourseName, CreditHours, LabSession
FROM Courses
WHERE LabSession = 'Y'
ORDER BY CourseId
Related
I have an Editable Interactive Grid (for product_sale table) with a Select List (to select a product) in Oracle Apex 20.2 app.
Currently I'm using below query to populate this list of values.
SELECT productName,productId FROM product WHERE productAvailability = 'Y'
There are a few products that I need to set the productAvailability as 'N'. When I made this change, Interactive Grid of product_sale shows productId instead of the productName.
What I need to achieve is, only show products with productAvailability = 'Y' for new records (when going to add new record in to the table by clicking Add Row button) and for the old records show the productName of the selected product regardless the productAvailability.
Table Structure
Sample Data
Interactive Grid View
How could I achieve this?
You can achieve this using the "cascading list of values" option in the column settings. Let me illustrate with an example on the EMP sample table - you should be able to translate this to your own code:
Situation: BLAKE can not be selected as manager for any other employees than the one he is already manager for.
This would be the select:
SELECT ename, empno FROM emp WHERE ename != 'BLAKE'
As expected, for records that have BLAKE as manager, the MGR column will display the id because the value is not in the result set of the select list query. This is the behaviour you are seeing.
The solution has 2 steps:
Union the query with a query that has the value of the current row. I have rewritten the query using a CTE.
WITH all_mgr(dv, rv) AS
(SELECT ename, empno FROM emp WHERE ename != 'BLAKE'
UNION
SELECT m.ename, m.empno
FROM emp e
JOIN emp m ON e.mgr = m.empno
WHERE e.ename = :ENAME
)
SELECT dv, rv FROM all_mgr
Make sure column ename from the current row is bind to :ENAME. In "Cascading List Of Values" set both "Parent Column" and "Items to Submit" to ENAME. Now the select list will take the current row value for :ENAME and the list of values will include 'BLAKE' for users that have 'BLAKE' as a manager.
Imagine, that I need to retrieve all records excluding, those, that are associated
with specific ID, for instance if you consider table below and chose RestaurantID 1, resulting table should not include rows, that contain CuisineID 3,4 and 7.
If RestaurantID is 6, then resulting table should return anything without CuisineID 1 and 8
and so on
My table
Kind regards
erwre
if you do a subselect with your query, you can get a list of which CuisineID's to exclude using the NOT IN clause.
select
t.*
from
mytable t
where
t.CuisineID NOT IN
(
select
t2.CuisineID
from
mytable t2
where
t2.ID = #YOUR_RESTAURANT_ID
)
I'm planning to do SQL expert examination.
I have doubts that answer D is correct:
Evaluate the following command:
CREATE TABLE employees
( employee_id NUMBER(2) PRIMARY KEY
, last_name VARCHAR2(25) NOT NULL
, department_id NUMBER(2)NOT NULL
, job_id VARCHAR2(8)
, salary NUMBER(10,2));
You issue
the following command to create a view that displays the IDs and last
names of the sales staff in the organization:
CREATE OR REPLACE VIEW sales_staff_vu AS
SELECT employee_id, last_name,job_id
FROM employees
WHERE job_id LIKE 'SA_%'
WITH CHECK OPTION;
Which two statements are true regarding the above view? (Choose two.)
A. It allows you to insert rows into the EMPLOYEES table .
B. It allows you to delete details of the existing sales staff from
the EMPLOYEES table.
C. It allows you to update job IDs of the existing sales staff to any
other job ID in the EMPLOYEES table.
D. It allows you to insert IDs, last names, and job IDs of the sales
staff from the view if it is used in multitable INSERT statements.
Source
A is FALSE as the view doesn't allow inserting into the department_id column which is mandatory.
B is TRUE, although it would be more accurate to say that the view only allows deletions of employees where the job_id matches the predicate LIKE 'SA_%'.
C is FALSE, as the WITH CHECK OPTION means that you can't change the job_id if the new job_id doesn't match the view's predicate.
D is FALSE: a multitable insert statement can't just insert some columns into the view and the remaining columns into the employees table. Even if you join the view to the table, the insert must still insert into the base table, not into the view:
insert into
(select e.employee_id, e.last_name, e.department_id, e.job_id
from sales_staff_vu v
join employees e
on v.employee_id = e.employee_id)
values
(1, 'KEMP', 2, 'SA_X');
I suspect this is a test of your ability to verify and ignore wrong information on the internet - i.e. 99% of sites say D is true!
Now, my answer can be easily disproved by crafting a multitable insert statement that successfully inserts via the view.
According to my knowledge answer D is wrong.Reasons are
1.If A is wrong, definitely D is wrong.because department_id column is mandatory field on the table, but it is not mentioned in view.so we can't insert a row using this view.
2.In Answer D,multitable INSERT statements are INSERT ALL, INSERT FIRST,etc.
to check this Answer,i have tried these steps
CREATE TABLE employees123
( employee_id NUMBER(2) PRIMARY KEY
, last_name VARCHAR2(25) NOT NULL
, department_id NUMBER(2)NOT NULL
, job_id VARCHAR2(8)
, salary NUMBER(10,2));
CREATE OR REPLACE VIEW sales_staff_vu123 AS
SELECT employee_id, last_name,job_id,department_id
FROM employees123
WHERE job_id LIKE 'SA_%'
WITH CHECK OPTION;
--department_id is added to view
--here i am trying to insert my employees table rows to employees123 table
INSERT ALL
INTO sales_staff_vu123 --using View
SELECT employee_id, last_name,job_id,department_id
FROM employees;
Error at Command Line:153 Column:15
Error report:
SQL Error: ORA-01702: a view is not appropriate here
01702. 00000 - "a view is not appropriate here"
*Cause:
*Action:
So my decision is we cant use views with multitable insert statements.
I have 2 tables, one is indexing the other.
I am querying Table#1, and it has one column (string) that has an ID in it that corresponds to a unique row in Table#2. Im trying to write a query in Sqlite that allows me to retrieve the value from Table#2 if the column value in Table#1 is not an empty string.
Kinda like:
"SELECT TMake,TModel,TTrim,IYear,[%q] AS TPart1 FROM AppGuide WHERE TPart1 != ''"
But instead of retrieving the Index value (TPart1) Id like to get the string from Table#2.
Is this possible?
Any help is appreciated.
You could use a correlated subquery:
SELECT TMake,
TModel,
...,
(SELECT stringvalue
FROM Table2
WHERE Table2.ID = Table1.TPart1)
FROM Table1
WHERE Table1.TPart1 != ''
However, these are rather slow to execute, so you'd better use a join (this returns exactly the same result):
SELECT Table1.TMake,
Table1.TModel,
...,
Table2.stringvalue
FROM Table1 LEFT JOIN Table2 ON Table1.TPart1 = Table2.ID
WHERE Table1.TPart1 != ''
If you don't want to get records from Table1 that have no matching Table2 record, drop the LEFT.
sql has a Table called emp.
emp(emp_id int IDENTITY primary key, EmployeeName varchar(50),.......)
I want to Insert a record to above table. Here is my code in asp.net.
DBconnection dbcon = new DBconnection();
string query = "insert into emp values('" + TextBox_EmpName.Text + "','" + ....);
int no1 = dbcon.insertQuery(query);
I have another table called emp-relation
emp-relation(emp_id int primary key, count int, ....)
-- foreign key (emp_id)references emp(emp_id)
My problem is when I inserting the emp row ,I dont know what is the emp_id since it created by auto. And when I am going to insert to emp-relation , I want to get emp-id since it is the foreign key.
How can I do this? Is there any way to read last Insert row in Sql according to Time stamp or some thing? I believe that records are not sorted according to inserted timestamp in nature. please help me.
There's bascally two ways. The first way is to return the new ID from the first insert query:
insert into emp values(...)
select scope_identity() as NewID
The second way is to lookup the first row when you insert into the relation table:
insert emp-relation
(emp_idm, ...)
select emp_id
, ...
from emp
where emp_name = #EmpName
You have to pass in enough columns to make the reference unique.