I am new to mysql and I am trying create a gradebook db to keep track of grades for a certain class. I am using Mysql workbench and here is my code:
SET #OLD_UNIQUE_CHECKS=##UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET #OLD_FOREIGN_KEY_CHECKS=##FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET #OLD_SQL_MODE=##SQL_MODE, SQL_MODE='TRADITIONAL';
DROP SCHEMA IF EXISTS nj1368843 ;
CREATE SCHEMA IF NOT EXISTS nj1368843 DEFAULT CHARACTER SET latin1 COLLATE latin1_swedish_ci ;
USE nj1368843 ;
-- Table nj1368843.Users
DROP TABLE IF EXISTS nj1368843.Users ;
CREATE TABLE IF NOT EXISTS nj1368843.Users (
idUsers INT NOT NULL AUTO_INCREMENT ,
UserName VARCHAR(45) NOT NULL ,
pw VARCHAR(45) NOT NULL ,
PRIMARY KEY (idUsers, UserName, pw) )
ENGINE = InnoDB;
INSERT INTO nj1368843.Users (UserName, pw) VALUES ('njack2', '123');
-- Table nj1368843.Teachers
DROP TABLE IF EXISTS nj1368843.Teachers ;
CREATE TABLE IF NOT EXISTS nj1368843.Teachers (
idTeachers INT NOT NULL ,
Lname VARCHAR(45) NULL ,
Fname VARCHAR(45) NULL ,
Users_idUsers INT NOT NULL ,
Users_pw VARCHAR(45) NOT NULL ,
PRIMARY KEY (idTeachers) ,
INDEX fk_Teachers_Users1 (Users_idUsers ASC, Users_pw ASC) ,
CONSTRAINT fk_Teachers_Users1
FOREIGN KEY (`Users_idUsers` , `Users_pw` )
REFERENCES `nj1368843`.`Users` (`idUsers` , `UserName` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
INSERT INTO nj1368843.Teachers (idTeachers, Lname, Fname, Users_idUsers, Users_pw) VALUES (105, 'Stacey', 'Sheila', '1', '123');
-- Table nj1368843.Schedule
DROP TABLE IF EXISTS nj1368843.Schedule ;
CREATE TABLE IF NOT EXISTS nj1368843.Schedule (
course_id INT NOT NULL ,
Semester VARCHAR(45) NULL ,
Year YEAR NULL ,
Teachers_idTeachers INT NOT NULL ,
PRIMARY KEY (course_id) ,
INDEX fk_Grades_Teachers1 (Teachers_idTeachers ASC) ,
CONSTRAINT fk_Grades_Teachers1
FOREIGN KEY (`Teachers_idTeachers` )
REFERENCES `nj1368843`.`Teachers` (`idTeachers` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- Table nj1368843.Assignments
DROP TABLE IF EXISTS nj1368843.Assignments ;
CREATE TABLE IF NOT EXISTS nj1368843.Assignments (
idAssignments INT NOT NULL ,
Assignment 1 INT NULL ,
AVG_Grade INT(11) NULL ,
Schedule_course_id INT NOT NULL ,
PRIMARY KEY (idAssignments) ,
INDEX fk_Assignments_Schedule1 (Schedule_course_id ASC) ,
CONSTRAINT fk_Assignments_Schedule1
FOREIGN KEY (`Schedule_course_id` )
REFERENCES `nj1368843`.`Schedule` (`course_id` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- Table nj1368843.Student
DROP TABLE IF EXISTS nj1368843.Student ;
CREATE TABLE IF NOT EXISTS nj1368843.Student (
idStudent INT NOT NULL ,
lname VARCHAR(45) NULL ,
fname VARCHAR(45) NULL ,
Schedule_course_id INT NOT NULL ,
Users_idUsers INT NOT NULL ,
Users_pw VARCHAR(45) NOT NULL ,
Assignments_idAssignments INT NOT NULL ,
PRIMARY KEY (idStudent) ,
INDEX fk_Student_Schedule1 (Schedule_course_id ASC) ,
INDEX fk_Student_Users1 (Users_idUsers ASC, Users_pw ASC) ,
INDEX fk_Student_Assignments1 (Assignments_idAssignments ASC) ,
CONSTRAINT fk_Student_Schedule1
FOREIGN KEY (`Schedule_course_id` )
REFERENCES `nj1368843`.`Schedule` (`course_id` )
ON DELETE NO ACTION
ON UPDATE NO ACTION,
CONSTRAINT fk_Student_Users1
FOREIGN KEY (`Users_idUsers` , `Users_pw` )
REFERENCES `nj1368843`.`Users` (`idUsers` , `UserName` )
ON DELETE NO ACTION
ON UPDATE NO ACTION,
CONSTRAINT fk_Student_Assignments1
FOREIGN KEY (`Assignments_idAssignments` )
REFERENCES `nj1368843`.`Assignments` (`idAssignments` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- Table nj1368843.Classes
DROP TABLE IF EXISTS nj1368843.Classes ;
CREATE TABLE IF NOT EXISTS nj1368843.Classes (
cid INT NOT NULL ,
Name VARCHAR(45) NULL ,
Schedule_course_id INT NOT NULL ,
PRIMARY KEY (cid) ,
INDEX fk_Classes_Schedule1 (Schedule_course_id ASC) ,
CONSTRAINT fk_Classes_Schedule1
FOREIGN KEY (`Schedule_course_id` )
REFERENCES `nj1368843`.`Schedule` (`course_id` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
-- Table nj1368843.Teachers
DROP TABLE IF EXISTS nj1368843.Teachers ;
CREATE TABLE IF NOT EXISTS nj1368843.Teachers (
idTeachers INT NOT NULL ,
Lname VARCHAR(45) NULL ,
Fname VARCHAR(45) NULL ,
Users_idUsers INT NOT NULL ,
Users_pw VARCHAR(45) NOT NULL ,
PRIMARY KEY (idTeachers) ,
INDEX fk_Teachers_Users1 (Users_idUsers ASC, Users_pw ASC) ,
CONSTRAINT fk_Teachers_Users1
FOREIGN KEY (`Users_idUsers` , `Users_pw` )
REFERENCES `nj1368843`.`Users` (`idUsers` , `UserName` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB;
SET SQL_MODE=#OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=#OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=#OLD_UNIQUE_CHECKS;
I generated this out of an erd diagram and I can't insert any information in the database because I get:
ERROR 1452: Cannot add or update a child row: a foreign key constraint fails (nj1368843.Teachers, CONSTRAINT fk_Teachers_Users1 FOREIGN KEY (Users_idUsers, Users_pw) REFERENCES Users (idUsers, UserName) ON DELETE NO ACTION ON UPDATE NO ACTION)
SQL Statement:
INSERT INTO nj1368843.Teachers (idTeachers, Lname, Fname, Users_idUsers, Users_pw) VALUES (105, 'Stacey', 'Sheila', 1, '123')
I tried everyone's ideas and looked over the code a million times and still can't find the problem. I can't insert into none of the tables for this db.help.
Related
I want to join table Saleperson with Table Salevolume. The Logic of the join is:
Table Saleperson has key: itemfrom and itemto, Table Salevolume has Key: Item. When the key "Item" from Salevolume is between the key "itemfrom" and "itemto" of saleperson, then i will make sume of salevolume, group by Saleperson
The Key "accountfrom" and "accountto" and "item" have sometime character at the end
Can you please help me ?
Thanks
CREATE TABLE [dbo].[Saleperson](
[Saleperson] [nvarchar](3) NULL,
[itemfrom] [nvarchar](4) NULL,
[itemto] [nvarchar](4) NULL
)
insert into [dbo].[Saleperson]
values
('A','111H','112H'),
('B','122G','125G'),
('C','134F','137F'),
('D','117','119'),
CREATE TABLE [dbo].[Salevolume](
[Item] [nvarchar](6) NULL,
[Salevolume] [int] NULL
)
insert into [dbo].[Salevolume]
values
('112H',30),
('113H',40),
('122G',30),
('134F',50),
('118',100)
You need to fist check if item's last charater is alphabet or not. if it is a alphabet then check whether numeric value and alphabet value of item is between that of numeric value and alphabet value of itemfrom and itemto respectively as shown below:
select p.Saleperson,sum(v.Salevolume)
from Saleperson p
inner join Salevolume v
on v.Item between p.itemfrom and p.itemto
OR (
RIGHT(v.Item,1) between 'A' and 'Z'
and RIGHT(v.Item,1) between RIGHT(p.itemfrom,1) AND RIGHT(p.itemto,1)
and REPLACE(v.item,RIGHT(v.Item,1),'') between REPLACE(p.itemfrom,RIGHT(p.itemfrom,1),'') and REPLACE(p.itemto,RIGHT(p.itemto,1),'')
)
group by p.Saleperson;
I can't get this simple query right. I need to join my adresses table to my annonces table.
I supose this should be farly strait forward but I simply can't get it to work.
I firstly made my adresse table object like this
class AdressesTable extends Table
{
public function initialize(array $config)
{
$this->belongsTo('Annonces', [
'foreignKey' => 'annonceId',
'joinType' => 'INNER',
]);
}
}
Then in my annonces controller I tryed to join the adresses like this
public function view($id = null)
{
if (!$id) {
throw new NotFoundException(__('Annonce invalide!'));
}
$query = $this->Annonces->find('all', ['contain' => ['Adresses']])->where(['id' => $id]);
$annonce = $query->firstOrFail();
$this->set(compact('annonce'));
}
But then I got this error :
Error: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'Adresses.annonce_id' in 'where clause'
Witch I don't understand why I got it since I have defined my foreign key in the AdressesTable class.
The query I would like to have at the end would look like this
SELECT *
FROM annonces
INNER JOIN adresses ON adresses.annonceId = annonces.id
WHERE annonces.id = #param
*PS. I know it wont be select * but rather select [all my column]*
EDIT : My table schema are as following
CREATE TABLE annonces(
id INT NOT NULL AUTO_INCREMENT, #PK
startDate DATE NOT NULL,
endDate DATE NOT NULL,
title VARCHAR(128) NOT NULL,
descript TEXT NOT NULL,
infoSupplementaire TEXT NULL,
premium BIT NOT NULL,
clientId INT NOT NULL, #FK
categorieId INT NOT NULL, #FK
CONSTRAINT pk_annonces_id PRIMARY KEY (id),
CONSTRAINT fk_annonces_clientId FOREIGN KEY (clientId) REFERENCES clients(id),
CONSTRAINT fk_annonces_categorieId FOREIGN KEY (categorieId) REFERENCES categories(id)
);
CREATE TABLE adresses(
id INT NOT NULL AUTO_INCREMENT, #PK
latitude DECIMAL(11,7),
longitude DECIMAL(11,7),
adresse VARCHAR(512),
annonceId INT NOT NULL, #FK
CONSTRAINT pk_adresses_id PRIMARY KEY (id),
CONSTRAINT fk_adresses_annonceId FOREIGN KEY (annonceId) REFERENCES annonces(id)
)
I solved my problem by renaming my column folowing cakephp convention and using any of the code from this answer
You can try
$query = $this->Annonces->find('all', ['contain' => ['Adresses']])->where(['Annonces.id' => $id]);
$annonce = $query->firstOrFail();
OR
public function view($id = null)
{
if (!$id) {
throw new NotFoundException(__('Annonce invalide!'));
}
$annonceEntity = $this->Annonces->get($id);
$query = $this->Annonces->find('all', ['contain' => ['Adresses']])->where(['Annonces.id' => $annonceEntity->id]);
$annonce = $query->firstOrFail();
$this->set(compact('annonce'));
}
I've added a new table to my DB:
CREATE TABLE myTable (
myId ID NOT NULL,
aNumber INTEGER NOT NULL,
anUniqueTextId TEXT NOT NULL,
aText TEXT,
PRIMARY KEY(myId, anUniqueTextId) ON CONFLICT IGNORE,
FOREIGN KEY(anUniqueTextId, aNumber) REFERENCES otherTable(otherTableId, otherTableValue2) ON DELETE CASCADE
);
Now I want to insert values without manually finding out which index should I put in myId field:
[myDatabase inTransaction:^(FMDatabase *db, BOOL *rollback) {
[db executeUpdate:#"INSERT INTO myTable VALUES(?,?,?)",
// #(myData.myId), //I don't want to insert it manually
#(aNumber),
myData.anUniqueTextId,
myData.aText];
if (db.lastErrorCode) {
NSLog(#"Huston, we've got a problem: %#", db.lastError.localizedDescription);
}
}];
Ofc, I get here an error telling:
table myTable has 4 columns but 3 values were supplied
Now the question is how to insert the data to make this field autoinsert myId? I'm not sure if my insert code is invalid or CREATE TABLE statement.
-- UPDATE --
I've updated create statement to correct one:
CREATE TABLE myTable (
myId INTEGER PRIMARY KEY DEFAULT 0 NOT NULL,
aNumber INTEGER NOT NULL,
anUniqueTextId TEXT NOT NULL,
aText TEXT,
FOREIGN KEY(anUniqueTextId, aNumber) REFERENCES otherTable(otherTableId, otherTableValue2) ON DELETE CASCADE
);
With respect to your comment you need to specify the PRIMARY KEY with a NULLvalue in the QUERY:
[db executeUpdate:#"INSERT INTO myTable VALUES(?,?,?,?)",
NULL,
#(aNumber),
myData.anUniqueTextId,
myData.aText];
That way the database will fill in the primary key and autoincrement it (SQL Lite specs for PRIMARY KEY).
Here you need to change the schema of table.
To auto insert into myId field, you must have to add constraint AUTOINCREMENT when you create table. Also this field must be use as primary key. So now the schema for table is like:
CREATE TABLE myTable (
myId INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL
aNumber INTEGER NOT NULL,
anUniqueTextId TEXT NOT NULL,
aText TEXT,
FOREIGN KEY(anUniqueTextId, aNumber) REFERENCES otherTable(otherTableId, otherTableValue2) ON DELETE CASCADE
);
I woud like to inquire if my Linq solution below is a good solution or if there is a better way. I am new to using Linq, and am most familiar with MySQL. So I've been converting one of my past projects from PHP to .NET MVC and am trying to learn Linq. I would like to find out if there is a better solution than the one I came up with.
I have the following table structures:
CREATE TABLE maplocations (
ID int NOT NULL AUTO_INCREMENT,
name varchar(35) NOT NULL,
Lat double NOT NULL,
Lng double NOT NULL,
PRIMARY KEY (ID),
UNIQUE KEY name (name)
);
CREATE TABLE reservations (
ID INT NOT NULL AUTO_INCREMENT,
loc_ID INT NOT NULL,
resDate DATE NOT NULL,
user_ID INT NOT NULL,
PRIMARY KEY (ID),
UNIQUE KEY one_per (loc_ID, resDate),
FOREIGN KEY (user_ID) REFERENCES Users (ID),
FOREIGN KEY (loc_ID) REFERENCES MapLocations (ID)
);
CREATE TABLE Users (
ID INT NOT NULL AUTO_INCREMENT,
name VARCHAR(20) NOT NULL,
email VARCHAR(50) NOT NULL,
pass VARCHAR(128) NOT NULL,
salt VARCHAR(5) NOT NULL,
PRIMARY KEY (ID),
UNIQUE KEY unique_names (name),
UNIQUE KEY unique_email (email)
);
In MySQL, I use the following query to get the ealiest reservation at each maplocation with a non null date for any locations that don't have a reservation.
SELECT locs.*, if(res.resDate,res.resDate,'0001-01-01') as resDate, res.Name as User
FROM MapLocations locs
LEFT JOIN (
SELECT loc_ID, resDate, Name
FROM Reservations, Users
WHERE resDate >= Date(Now())
AND user_ID = Users.ID
ORDER BY resDate
) res on locs.ID = res.loc_ID
group by locs.ID
ORDER BY locs.Name;
In Linq, with Visual studio automatically creating much of the structure after connecting to the database, I have come up with the following equivalent to that SQL Query
var resList = (from res in Reservations
where res.ResDate >= DateTime.Today
select res);
var locAndRes =
(from loc in Maplocations
join res in resList on loc.ID equals res.Loc_ID into join1
from res2 in join1.DefaultIfEmpty()
join usr in Users on res2.User_ID equals usr.ID into join2
from usr2 in join2.DefaultIfEmpty()
orderby loc.ID,res2.ResDate
select new {
ID = (int)loc.ID,
Name = (string)loc.Name,
Lat = (double)loc.Lat,
Lng = (double)loc.Lng,
resDate = res2 != null ?(DateTime)res2.ResDate : DateTime.MinValue,
user = usr2 != null ? usr2.Name : null
}).GroupBy(a => a.ID).Select(b => b.FirstOrDefault());
So, I'm wondering is there a better way to perform this query?
Are these equivalent?
Are there any good practices I should be following?
Also, one more question, I'm having trouble getting this from the var to a List. doing something like this doesn't work
List<locAndResModel> locList = locAndRes.AsQueryable().ToList<locAndResModel>();
In the above snippet locAndResModel is just a class which has variables to match the int, string, double double, DateTime, string results of the query. Is there an easy way to get a list without having to do a foreach and passing the results to a constructor override? Or should I just add it to ViewData and return the View?
You'll want to take advantage of the automatic joins performed by the Entity Framework. Give this a try and let me know if it does what you want:
var locAndRes = from maplocation in MapLocations
let earliestReservationDate = maplocation.Reservations.Min(res => res.resDate)
let earliestReservation = (from reservation in mapLocation.Reservations
where reservation.resDate == earliestReservationDate && reservation.resDate >= DateTime.Today
select reservation).FirstOrDefault()
select new locAndResModel( maplocation.ID, maplocation.name, maplocation.Lat, maplocation.Lng, earliestReservation != null ? earliestReservation.resDate : DateTime.MinValue, earliestReservation != null ?earliestReservation.User.name : null)
Run into a strange problem while writing an ASP.NET MVC site. I have a view in my SQL Server database that returns a few date ranges. The view works fine when running the query in SSMS.
When the view data is returned by the Entity Framework Model, It returns the correct number of rows but some of the rows are duplicated.
Here is an example of what I have done:
SQL Server code:
EDITED: (table A)
CREATE TABLE [dbo].[A](
[ID] [int] NOT NULL,
[PhID] [int] NULL,
[FromDate] [datetime] NOT NULL,
[ToDate] [datetime] NULL,
CONSTRAINT [PK_A] PRIMARY KEY CLUSTERED
( [ID] ASC,
[FromDate] ASC
)) ON [PRIMARY]
CREATE TABLE [dbo].[B](
[PhID] [int] NOT NULL,
[FromDate] [datetime] NULL,
[ToDate] [datetime] NULL,
CONSTRAINT [PK_B] PRIMARY KEY CLUSTERED
( [PhID] ASC )) ON [PRIMARY]
go
CREATE VIEW C as
SELECT A.ID,
CASE WHEN A.PhID IS NULL THEN A.FromDate ELSE B.FromDate END AS FromDate,
CASE WHEN A.PhID IS NULL THEN A.ToDate ELSE B.ToDate END AS ToDate
FROM A
LEFT OUTER JOIN B ON A.PhID = B.PhID
go
INSERT INTO B (PhID, FromDate, ToDate) VALUES (100, '20100615', '20100715')
INSERT INTO A (ID, PhID, FromDate, ToDate) VALUES (1, NULL, '20100101', '20100201')
INSERT INTO A (ID, PhID, FromDate, ToDate) VALUES (1, 100, '20100615', '20100715')
INSERT INTO B (PhID, FromDate, ToDate) VALUES (101, '20101201', '20101231')
INSERT INTO A (ID, PhID, FromDate, ToDate) VALUES (2, NULL, '20100801', '20100901')
INSERT INTO A (ID, PhID, FromDate, ToDate) VALUES (2, 101, '20101201', '20101231')
So now, if you select all from C, you get 4 separate date ranges
In the Entity Framework Model (which I call 'Core'), the view 'C' is added.
in MVC Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
CoreEntities db = new CoreEntities();
var clist = from c in db.C
select c;
return View(clist.ToList());
}
}
in MVC View:
#model List<RM.Models.C>
#{
foreach (RM.Models.C c in Model)
{
#String.Format("{0:dd-MMM-yyyy}", c.FromDate)
<span>-</span>
#String.Format("{0:dd-MMM-yyyy}", c.ToDate)
<br />
}
}
When I run all this, it outputs this:
01-Jan-2010 - 01-Feb-2010
01-Jan-2010 - 01-Feb-2010
01-Aug-2010 - 01-Sep-2010
01-Aug-2010 - 01-Sep-2010
When it should do this (this is what the view returns):
01-Jan-2010 - 01-Feb-2010
15-Jun-2010 - 15-Jul-2010
01-Aug-2010 - 01-Sep-2010
01-Dec-2010 - 31-Dec-2010
Also, I've run the SQL profiler over it and according to that, the query being executed is:
SELECT
[Extent1].[ID] AS [ID],
[Extent1].[FromDate] AS [FromDate],
[Extent1].[ToDate] AS [ToDate]
FROM (SELECT
[C].[ID] AS [ID],
[C].[FromDate] AS [FromDate],
[C].[ToDate] AS [ToDate]
FROM [dbo].[C] AS [C]) AS [Extent1]
Which returns the correct data
So it seems that the entity framework is doing something to the data in the meantime.
To me, everything looks fine! Have I missed something?
Cheers,
Ben
EDIT:
sorry, table A should be:
CREATE TABLE [dbo].[A](
[ID] [int] NOT NULL,
[PhID] [int] NULL,
[FromDate] [datetime] NOT NULL,
[ToDate] [datetime] NULL,
CONSTRAINT [PK_A] PRIMARY KEY CLUSTERED
( [ID] ASC,
[FromDate] ASC
)) ON [PRIMARY]
I figured it out myself.
The problem was with the way the view was mapped in the entity model.
When it was added, it made the entity key just the ID. I needed it over the ID and FromDate. So I included the FromDate in the entity key and it works fine.