First, the table:
CLASS CLASS_NAME PROFESSOR NUMBER_OF_STUDENTS COST START_DAT END_DATE ROO
----- -------------------- ------------------ ------------------ ---------- --------- --------- ---
PC102 Peripherals Henry Higgins 12 $1,100.00 11-JAN-13 11-MAY-13 129
PC101 MS OFFICE BASICS INDIANA JONES 18 $1,000.00 10-JAN-13 10-MAY-13 127
EE101 Elementary Education Frank McCourt 22 $900.00 12-JAN-13 12-MAY-13 227
PC123 MS OFFICE ADVANCED Bill Gates 10 $800.00 13-JAN-13 13-MAY-13 180
The problem:
Add a check constraint to number of students to ensure capacity is between 12 and 25
students.
What I've tried
ALTER TABLE BW_CLASS
ADD CHECK( NUMBER_OF_STUDENTS > 15 AND
NUMBER_OF_STUDENTS < 25);
What is returned
ERROR at line 1:
ORA-02293: cannot validate (STUDENT.SYS_C007516) - check constraint violated
What am I doing wrong?
The table you're trying to apply the check to already has values that fail the check. Fix the entries in the table that fail, then apply the check.
Make sure the number of students in each class is between 12 and 25. update table, where number of students is below 12 increase to > 12. Where it's higher than 25 reduce.
Related
This request might be asked many times but I have done a search last night to figure out but I came up with nothing.
I have three tables
Table A
ID
City
1
LA
2
NY
3
LV
Table B
ID
Job
11
Programmer
22
Engineer
33
Database Administrator
44
Cyber Security Analyst
Table C
ID
Job level
111
Junior
222
Associate
333
Senior
444
Director
Final table
ID
EmployeeName
City_ID
Job_ID
Level_ID
1000
Susie
1
11
333
1001
Nora
2
11
222
1002
Jackie
2
22
111
1003
Mackey
1
11
444
1004
Noah
1
11
111
I’d like to have a crosstab query using Microsoft Access that returns the following result ( based on city )
LA Table
Jobs
Junior
Associate
Senior
Director
Programmer
1
-
1
1
Engineer
-
-
-
-
Database Administrator
-
-
-
-
Cyber Security Analyst
-
-
-
-
How can I do it?
The best approach for this is always:
Create a "base" query that joins the base tables and returns all data columns that you will need for the crosstab query.
Run the crosstab query wizard using the "base" query as input.
I'm trying to answer these questions but I couldn't and I need here
1) List the number of days that have elapsed since each student joined.
this what I did
Select FR_FIRSTNAME,
FR_LASTNAME,
trunc(sysdate - FR_DATEJOINED) / 7 DAYS
from alharbi_bandar5_FRESHMEN;
no rows selected
2) List the student names and city in upper case.
This what i did
Select FR_FIRSTNAME, FR_LASTNAME, CITY FROM alharbi_bandar5_FRESHMEN
where UPPER (FR_FIRSTNAME, FR_LASTNAME, CITY) like 'SMITH%';
> where UPPER (FR_FIRSTNAME, FR_LASTNAME, CITY) like 'SMITH%'
*
ERROR at line 2:
ORA-00909: invalid number of arguments
3) List the no and last name of the student(s) with the highest ACT score.
This what i did
Select FR_NO, FR_LASTNAME, ACT from alharbi_bandar5_FRESHME
where ACT = MAX(ACT);
where ACT = MAX(ACT)
*
ERROR at line 2:
ORA-00934: group function is not allowed here
this is my table
FR_ FR_FIRSTNAME FR_LASTNAME FR_DATEJO ACT CITY
--- ------------------------------ ------------------------------ --------- ---------- ------------------------------
100 Mark Ramon 12-JUL-13 21 Florence
101 John Wright 13-JUN-13 31 Edgewood
102 Peter Sellers 06-JAN-13 30 Blue Ash
103 Eric Bates 14-MAY-13 24 Milford
104 Theresa Boyers 23-APR-13 22 Covingtion
105 Alex William 04-MAR-13 24 Edgewood
106 Eric Byrd 23-MAR-13 19 Alexandria
107 Steve Norris 21-DEC-12 21 Highland
108 Lisa Nkosi 13-FEB-13 33 Florence
109 Bradley Rego 21-FEB-12 29 Covington
110 Kathy Thomas 15-OCT-12 27 Milford
111 Catherine Jones 17-APR-13 34 Edgewood
112 Emily Hess 15-NOV-12 36 Highland
113 Josha Hunter 19-MAY-14 31 Florence
A lot of these questions have answers in the Oracle SQL reference and are mostly syntax issues.
1) trunc(sysdate - FR_DATEJOINED) / 7 DAYS
Oracle gies out the number of days in the units of difference, so sysdate - FR_DATEJOINED would gie you number of days, which could also involve fractional component (2.5 days for example, if it has been 2 days and 12 hours since the candidate joined). Trunc would get rid of the fractional component, but "/7" would convert the result into number of weeks instead. why are you doing this?
Either way, i don't believe this query is being fired against the table below, otherwise you'd not get zero rows as you are not filtering anything at all.
Check these out for more info on Oracle's date functions.
http://docs.oracle.com/cd/E17952_01/refman-5.1-en/date-and-time-functions.html
https://www.youtube.com/watch?v=H18UWBoHhHY
2) UPPER function accepts a column name or an expression, so if you need multiple columns. you'd need to use UPPER around each column.
3) For this example, you'll need to use a subquery to get the max value first and then use the query on top.
getting the max value
Select max(act) from alharbi_bandar5_FRESHME;
so, final query would be...
Select FR_NO, FR_LASTNAME, ACT from alharbi_bandar5_FRESHME
where ACT = (select MAX(ACT) from alharbi_bandar5_FRESHME);
Or, you could use the oracle rank function..
select fr_no,
fr_last_name,
act
from (
select fr_no, fr_lastname, act,
rank () over (order by act desc) rnk
from alharbi_bandar5_FRESHME
) where rnk = 1
The project I'm asking about is for sending an email to teachers asking what books they're using for the classes they're teaching next semester, so that the books can be ordered. I have a query that compares the course number of this upcoming semester's classes to the course numbers of historical textbook orders, pulling out only those classes that are being taught this semester. That's where I get lost.
I have a table that contains the following:
Professor
Course Number
Year
Book Title
The data looks like this:
professor year course number title
--------- ---- ------------- -------------------
smith 13 1111 Pride and Prejudice
smith 13 1111 The Fountainhead
smith 13 1222 The Alchemist
smith 12 1111 Pride and Prejudice
smith 11 1222 Infinite Jest
smith 10 1333 The Bible
smith 13 1333 The Bible
smith 12 1222 The Alchemist
smith 10 1111 Moby Dick
johnson 12 1222 The Tipping Point
johnson 11 1333 Anna Kerenina
johnson 10 1333 Everything is Illuminated
johnson 12 1222 The Savage Detectives
johnson 11 1333 In Search of Lost Time
johnson 10 1333 Great Expectations
johnson 9 1222 Proust on the Shore
Here's what I need the code to do "on paper":
Group the records by professor. Determine every unique course number in that group, and group records by course number. For each unique course number, determine the highest year associated. Then spit out every record with that professor+course number+year combination.
With the sample data, the results would be:
professor year course number title
--------- ---- ------------- -------------------
smith 13 1111 Pride and Prejudice
smith 13 1111 The Fountainhead
smith 13 1222 The Alchemist
smith 13 1333 The Bible
johnson 12 1222 The Tipping Point
johnson 11 1333 Anna Kerenina
johnson 12 1222 The Savage Detectives
johnson 11 1333 In Search of Lost Time
I'm thinking I should make a record set for each teacher, and within that, another record set for each course number. Within the course number record set, I need the system to determine what the highest year number is - maybe store that in a variable? Then pull out every associated record so that if the teacher ordered 3 books the last time they taught that class (whether it was in 2013 or 2012 and so on) all three books display. I'm not sure I'm thinking of record sets in the right way, though.
My SQL so far is basic and clearly doesn't work:
SELECT [All].Professor, [All].Course, Max([All].Year)
FROM [All]
GROUP BY [All].Professor, [All].Course;
Use your query as a subquery and INNER JOIN it back to the [ALL] table to filter the rows.
SELECT
a.Professor,
a.Year,
a.Course,
a.title
FROM
[ALL] AS a
INNER JOIN
(
SELECT [All].Professor, [All].Course, Max([All].Year) AS MaxOfYear
FROM [All]
GROUP BY [All].Professor, [All].Course
) AS sub
ON
a.Professor = sub.Professor
AND a.Course = sub.Course
AND a.Year = sub.MaxOfYear;
As defined here, the maximum number of compound select term is SQLITE_MAX_COMPOUND_SELECT
How can we get this value when we query a sqlite database using a sql command?
e.g.
select SQLITE_MAX_COMPOUND_SELECT from SomeTableSomeWhere
or
select someFunctionForThisValue()
well, I can not answer your directly to your question, but as we know SQLITE_MAX_COMPOUND_SELECT default defined 500. We can go around with this by using SELECT LIMIT, OFFSET statement to fetch all data in a large table (hope this is want you want)
for example:
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
With help of count rows
sqlite> SELECT count(*) FROM COMPANY
We can select limit rows with offset to fetch all database table
sqlite> SELECT * FROM COMPANY LIMIT 3 OFFSET 2;
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
reference here: http://www.tutorialspoint.com/sqlite/sqlite_limit_clause.htm
Foreign Key Not Populating with Primary Key Values
I did a lot of searching on the site, but I am relatively new to writing code for a database. I read a few threads like the one listed above, but I was unable to utilize the information within to solve my problem. I have two tables, customer and billing. The customer table is below:
SQL> SELECT * FROM CUSTOMER;
CUST_ID NAME BILL_NUM
-------------------- ------------------- ----------
432 MICHAEL MAYS
433 VILMA PACULAN
434 RUBY PUKE
435 ROWENA JOHNSON
436 MAGIC JOHNSON
437 DARTH VADER
438 OBI WAN
439 YODA
440 STEWIE GRIFFIN
441 EVIL MONKEY
442 HARRY POTTER
Bill table:
SQL> SELECT * FROM BILL
2 ;
BILL_NUM TOTAL
---------- ----------
1000 5.5
1001 7.4
1002 12.5
1003 14.56
1004 25.36
1005 66.66
1006 99.97
1007 56.67
1008 5.23
1009 87.25
1010 36.17
As you can see in the customer table the FK Bill_Num is null. I need to know how to insert the data into the column, to match the PK data? I am using oracle 10g SQLPlus. Any help would be greatly appreciated!
If you look at your current data set up, there is no common column (implicit or explicit) that would link these two tables. As a result, it is impossible to automatically link the tables.
You either need a transaction table in the form:
CUST_ID | Bill_NUM (many to many)
Or as Graeme stated put the CUST_ID on the Bill table as right now your many-to-one relationship will be the opposite of what would be expected.
http://en.wikipedia.org/wiki/Database_normalization - A good place to start on normalizing a database