Cannot create Access tables through SQL view - sql

I'm trying to create 3 access tables in SQL view on Microsoft Access but whenever I try to execute it, I receive the following error. 'Syntax Error in CREATE TABLE statement'.
Please find my code below.
CREATE TABLE Book (
Book_ID int,
Book_Title varchar (30),
PRIMARY KEY (Book_ID)
);
CREATE TABLE Users (
User_ID int,
User_Name varchar (30),
PRIMARY KEY (User_ID)
);
CREATE TABLE Borrows (
User_ID int,
Book_ID int,
B_ID int,
PRIMARY KEY(B_ID),
FOREIGN KEY(User_ID) REFERENCES Users(User_ID),
FOREIGN KEY(Book_ID) REFERENCES Book(Book_ID)
);
INSERT INTO Book VALUES (101, 'The Hobbit'), (102, 'To Kill a Mockingbird');
INSERT INTO Users VALUES (1, 'Stephen'), (2, 'Tom'), (3,' Eric');
INSERT INTO Borrows VALUES (3, 102, 1), (1, 101, 2);
Appreciate any feedback I can get, have a good day.

Your first CREATE TABLE executed flawlessly from the query designer in Access 2010. However my preference is to include the PRIMARY KEY constraint as part of the field definition:
CREATE TABLE Book (
Book_ID int PRIMARY KEY,
Book_Title varchar (30)
);
That variation also executed successfully.
I suspect you have at least 2 issues to resolve:
Access does not allow you to execute more than one SQL statement at a time (as Heinzi and Albert mentioned). You must execute them one at a time.
In Access, INSERT ... VALUES can only be used to add one row at a time. Revise your inserts accordingly.
IOW, split the first one into 2 statements which you then execute individually:
-- INSERT INTO Book VALUES (101, 'The Hobbit'), (102, 'To Kill a Mockingbird');
INSERT INTO Book VALUES (101, 'The Hobbit');
INSERT INTO Book VALUES (102, 'To Kill a Mockingbird');
Then split and execute the remaining inserts similarly.

Your code example use SQL Server (T-SQL) syntax, not MS Access syntax.
The syntax for Access' CREATE TABLE statement is documented here:
https://learn.microsoft.com/en-us/office/client-developer/access/desktop-database-reference/create-table-statement-microsoft-access-sql
The most obvious differences seem to be there is no varchar type and that PRIMARY KEY needs a constraint name if specified in an extra line. There might be more, see the article and its examples for details. I also suggest that you submit your statements one-by-one, instead of submitting a complete ;-separated batch; I'm not sure Access queries even support the latter.

Related

Securing values for other tables from enumerable table in SQL Server database

English is not my native language, so I might have misused words Enumerator and Enumerable in this context. Please get a feel for what I'm trying to say and correct me if I'm wrong.
I'm looking into not having tables for each enumerator I need in my database.
I "don't want" to add tables for (examples:) service duration type, user type, currency type, etc. and add relations for each of them.
Instead of a table for each of them which values will probably not change a lot, and for which I'd have to create relationships with other tables, I'm looking into having just 2 tables called Enumerator (eg: user type, currency...) and Enumerable (eg: for user type -> manager, ceo, delivery guy... and for currency -> euro, dollar, pound...).
Though here's the kicker. If I implement it like that, I'm loosing the rigidity of the foreign key relationships -> I can't accidentally insert a row in users table that will have a user type of some currency or service duration type, or something else.
Is there another way to resolve the issue of having so many enumerators and enumerables with the benefit of having that rigidity of the foreign key and with the benefit of having all of them in just those 2 tables?
Best I can think of is to create a trigger for BEFORE UPDATE and BEFORE INSERT to check if (for example) the column type of user table is using the id of the enumerable table that belongs to the correct enumerator.
This is a short example in SQL
CREATE TABLE [dbo].[Enumerator]
(
[Id] INT NOT NULL PRIMARY KEY,
[Name] VARCHAR(50)
)
CREATE TABLE [dbo].[Enumerable]
(
[Id] INT NOT NULL PRIMARY KEY,
[EnumeratorId] INT NOT NULL FOREIGN KEY REFERENCES Enumerator(Id),
[Name] VARCHAR(50)
)
INSERT INTO Enumerator (Id, Name)
VALUES (1, 'UserType'),
(2, 'ServiceType');
INSERT INTO Enumerable (Id, EnumeratorId, Name) -- UserType
VALUES (1, 1, 'CEO'),
(2, 1, 'Manager'),
(3, 1, 'DeliveryGuy');
INSERT INTO Enumerable (Id, EnumeratorId, Name) -- ServiceDurationType
VALUES (4, 2, 'Daily'),
(5, 2, 'Weekly'),
(6, 2, 'Monthly');
CREATE TABLE [dbo].[User]
(
[Id] INT NOT NULL PRIMARY KEY IDENTITY (1,1),
[Type] INT NOT NULL FOREIGN KEY REFERENCES Enumerable(Id)
)
CREATE TABLE [dbo].[Service]
(
[Id] INT NOT NULL PRIMARY KEY IDENTITY (1,1),
[Type] INT NOT NULL FOREIGN KEY REFERENCES Enumerable(Id)
)
The questions are:
Is it viable to resolve enumerators and enumerables with 2 tables and with before update and before insert triggers, or is it more trouble than it's worth?
Is there a better way to resolve this other than using before update and before insert triggers?
Is there a better way to resolve enumerators and enumerables that is not using 2 tables and triggers, nor creating a table with relations for each of them?
I ask for your wisdom as I don't have one or more big projects behind me and I didn't get a chance to create a DB like this until now.

How can I insert values into a table with a composite primary key?

These are the tables I already have:
CREATE TABLE Gyartok
(
GyID INT IDENTITY(2, 3),
Nev VARCHAR(20),
CONSTRAINT PK_Gyartok PRIMARY KEY (GyID)
)
CREATE TABLE Focicsuka
(
CsID INT IDENTITY(2, 2),
Meret INT,
CONSTRAINT PK_Focicsuka PRIMARY KEY (CsID)
)
CREATE TABLE FcsGyartjaGya
(
GyID INT IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1
FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2
FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya
PRIMARY KEY (GyID, CsID)
)
The problem is that every time I try to add new values to the table (like such)
INSERT INTO FcsGyartjaGya (Ar) VALUES (300);
I get an error saying I didn't initialize the CsID INT column:
Cannot insert the value NULL into column 'CsID', table 'Lab3.dbo.FcsGyartjaGya'; column does not allow nulls. INSERT fails.
I know I must initialize it with something, but I have no idea what do to it with, because IDENTITY(x, y) doesn't work (it's occupied by another column already) and adding another parameter to the code (like such)
INSERT INTO FcsGyartjaGya (Ar, CsID) VALUES (300, 7);
creates another error which says
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Lab3a", table "dbo.Gyartok", column 'GyID'.
It is important to note that I already filled every column with data, so that couldn't be the problem.
As I mention in the comments, your INSERT will work fine, provided the stars align correctly. For your table Gyartok you have GyID as your PRIMARY KEY, which is defined as a IDENTITY(2,3); so the first value generated is 2 and then each row attempted to be INSERTed will increment by 3.
So, if we run the following, we get the IDs 2, 5, 7 and 17. (11 and 14 are skipped as the INSERT failed).
CREATE TABLE Gyartok (
GyID INT IDENTITY(2, 3),
Nev VARCHAR(20),
CONSTRAINT PK_Gyartok PRIMARY KEY (GyID)
);
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES ('asdfjahsbvd'),
('ashjkgdfakd'),
('kldfbhjo');
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES (REPLICATE('A',25)), --Force a truncation error
('ashjkgdfakd');
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES (REPLICATE('A',15));
Let's now add some data for your other table:
CREATE TABLE Focicsuka (
CsID INT IDENTITY(2, 2),
Meret INT,
CONSTRAINT PK_Focicsuka PRIMARY KEY (CsID)
)
INSERT INTO dbo.Focicsuka (Meret)
VALUES(12),
(25);
Now we want to INSERT into the table FcsGyartjaGya, defined as the following:
CREATE TABLE FcsGyartjaGya (
GyID INT IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1 FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2 FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya PRIMARY KEY (GyID, CsID)
)
This has a IDENTITY on GyID, but defined as an IDENTITY(3,2), so the first value is 3 and then incremented by 2.
As this has 2 foreign keys, on GyID and CsID when we INSERT the row the values must appear in the respective tables. As GyID is defined as anIDENTITY(3,2) however, this is where we need to rely on the Stars luck for the INSERT to work. Why? Well 2 + (3*n) and 3+(2*n) can give very different numbers. The first are as you saw at the start of this answer. For the latter, we have numbers like 3, 5, 7, 9, 11. As you can see, only 1 in 3 of these numbers match a number in our original sequence, so luck is what we are going to be relying on.
Let's, therefore, try a single INSERT.
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(2,1);
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Sandbox", table "dbo.Gyartok", column 'GyID'.
Well, that didn't work, but it was expected. 3 isn't a value in the table Gyartok. Let's try again!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(2,2);
It worked! The stars Luck was our side, and the IDENTITY value was a value in the table Gyartok. Let's try a couple of rows this time!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,3),
(4,4);
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Sandbox", table "dbo.Gyartok", column 'GyID'.
No!! Not again. :( That's because the stars didn't align; 7 and 9 aren't in the other table. But wait, 11 was in the sequence, so let's try that:
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,5);
Error, again?! No, it cannot be!!! :( Oh wait, I forgot, the stars were against us before, because that INSERT failed against Gyartok for the value of 11. I need to wait for 17!
--13 fails
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
GO
--15 fails
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
GO
--17 works!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
And now we have another row in our table.
So what is the problem? Your design. GyID is defined as an IDENTITY and a FOREIGN KEY; meaning you are at the "whims" of SQL Server generating a value valid. This is not what you want. Just don't define the column as an IDENTITY and then INSERT the data with all 3 of your columns defined:
CREATE TABLE FcsGyartjaGya (
GyID int,-- IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1 FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2 FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya PRIMARY KEY (GyID, CsID)
)
GO
INSERT INTO dbo.FcsGyartjaGya (GyID, CsID, Ar)
VALUES(2,2,1),
(2,4,2),
(5,4,3),
(8,2,4),
(8,4,5);
And all these rows insert fine.
I think there is a bit confusion, if I understand correctly what You're trying to do, then you have two tables each with their own id, which is based on an identity column, so you get new values in those for free.
Then you are trying to make a relation table with extra data.
Issue 1: You cannot have FcsGyartjaGya.GyID be identity if it refers to Gyartok.GyID because you will want to insert into it and not rely on an auto increment. If it doesn't refer to the same it should have another name or my head will possibly explode :))
Issue 2: When populating a relation table you need to insert it with what pairs you want, there is no way SQL server can know how it should match these identity pairs in the relation table
I think this is what people are aiming at in the comments, for example
to insert a relationship between row with Focicsuka.CsID = 1 to Gyartok.GyID 7 and adding Ar = 300 have to look like
INSERT INTO FCSGYARTJAGYA(GYID, CSID, AR)
VALUES(7, 1, 300)
Unless You've forgotten to mention that you want to put some value for each of some value or based on something which can be scripted, in other words unless You have logics to define the pairs and their values, relationship tables cannot have defaults on their foreign key fields.

How to get ID of an identity column?

I have a many-to-many relationship between two tables, Users and Projects.
The table that connects those two together is named ProjectsUsers.
Here is the description of the tables and their relationships:
CREATE TABLE "Users"
(
Email VARCHAR(320) COLLATE SQL_Latin1_General_CP1_CI_AS PRIMARY KEY CHECK(LEN(Email) >= 3),
--More....
);
CREATE TABLE "Projects"
(
ProjectID INT PRIMARY KEY IDENTITY,
--More....
);
CREATE TABLE "ProjectsUsers"
(
UsersEmail VARCHAR(320) COLLATE SQL_Latin1_General_CP1_CI_AS CHECK(LEN(UsersEmail) >= 3) NOT NULL,
ProjectsID INT NOT NULL,
CONSTRAINT ProjectsUsers_PK PRIMARY KEY (UsersEmail, ProjectsID),
CONSTRAINT ProjectsID_FK FOREIGN KEY (ProjectsID) REFERENCES Projects (ProjectID)
ON DELETE CASCADE ON UPDATE CASCADE ,
CONSTRAINT UsersEmail_FK FOREIGN KEY (UsersEmail) REFERENCES Users(Email)
ON DELETE CASCADE ON UPDATE CASCADE
);
I am now trying to create a stored procedure that will insert a new project to the Projects table. After I add the project I want to create a reference to it in the ProjectsUsers table. The problem is, there is no possible way for me to know what the id of the project I just created - thus, I am unable to know what ID should I insert into the ProjectsUsers.
So if my stored procedure was something like this:
INSERT INTO Projects (Project, CreationDate, ProjectName)
VALUES (#project, GETDATE(), #email);
INSERT INTO ProjectsUsers VALUES (#email, ???)
How can I get the ID?
Just use SCOPE_IDENTITY like this:
INSERT INTO Projects (Project, CreationDate, ProjectName)
VALUES (#project, SYSDATETIME(), #email);
DECLARE #ProjectID INT = SCOPE_IDENTITY();
INSERT INTO ProjectsUsers
VALUES (#email, #ProjectID)
More all the relevant details about SCOPE_IDENTITY on the official Microsoft Documentation site.
As Sean Lange mentions, you can use SCOPE_IDENTITY to get last id inserted from within your proc
You can also use the OUTPUT clause and get possibly many ids. You can output in the screen or in a table, but it wont work if you are selecting from a table that has triggers.
Use the OUTPUT clause! Do not use the various identity functions or variables. This directly solves your problem:
DECLARE #ids TABLE (ProjectId int);
INSERT INTO Projects (Project, CreationDate, ProjectName)
OUTPUT inserted.ProjectId INTO #ids;
VALUES (#project, GETDATE(), #email);
INSERT INTO ProjectsUsers (UsersEmail, ProjectId)
SELECT #email, ProjectId
FROM #ids;
All the other methods of returning the identity have peculiarities:
Perhaps they don't work when the insert has multiple statements.
Perhaps concurrent inserts mess up the value.
Perhaps they don't work well with triggers.

Database Normalization using Foreign Key

I have a sample table like below where Course Completion Status of a Student is being stored:
Create Table StudentCourseCompletionStatus
(
CourseCompletionID int primary key identity(1,1),
StudentID int not null,
AlgorithmCourseStatus nvarchar(30),
DatabaseCourseStatus nvarchar(30),
NetworkingCourseStatus nvarchar(30),
MathematicsCourseStatus nvarchar(30),
ProgrammingCourseStatus nvarchar(30)
)
Insert into StudentCourseCompletionStatus Values (1, 'In Progress', 'In Progress', 'Not Started', 'Completed', 'Completed')
Insert into StudentCourseCompletionStatus Values (2, 'Not Started', 'In Progress', 'Not Started', 'Not Applicable', 'Completed')
Now as part of normalizing the schema I have created two other tables - CourseStatusType and Status for storing the Course Status names and Status.
Create Table CourseStatusType
(
CourseStatusTypeID int primary key identity(1,1),
CourseStatusType nvarchar(100) not null
)
Insert into CourseStatusType Values ('AlgorithmCourseStatus')
Insert into CourseStatusType Values ('DatabaseCourseStatus')
Insert into CourseStatusType Values ('NetworkingCourseStatus')
Insert into CourseStatusType Values ('MathematicsCourseStatus')
Insert into CourseStatusType Values ('ProgrammingCourseStatus')
Insert into CourseStatusType Values ('OperatingSystemsCourseStatus')
Insert into CourseStatusType Values ('CompilerCourseStatus')
Create Table Status
(
StatusID int primary key identity(1,1),
StatusName nvarchar (100) not null
)
Insert into Status Values ('Completed')
Insert into Status Values ('Not Started')
Insert into Status Values ('In Progress')
Insert into Status Values ('Not Applicable')
The modified table is as below:
Create Table StudentCourseCompletionStatus1
(
CourseCompletionID int primary key identity(1,1),
StudentID int not null,
CourseStatusTypeID int not null CONSTRAINT [FK_StudentCourseCompletionStatus1_CourseStatusType] FOREIGN KEY (CourseStatusTypeID) REFERENCES dbo.CourseStatusType (CourseStatusTypeID),
StatusID int not null CONSTRAINT [FK_StudentCourseCompletionStatus1_Status] FOREIGN KEY (StatusID) REFERENCES Status (StatusID),
)
I have few question on this:
Is this the correct way to normalize it ? The old table was very helpful to get data easily - I can store a student's course status in a single row, but now 5 rows are required. Is there a better way to do it?
Moving the data from the old table to this new table seems to be not an easy task. Can I achieve this using a query or I have to manually to do this ?
Any help is appreciated.
vou could also consider storing results in flat table like this:
studentID,courseID,status
1,1,"completed"
1,2,"not started"
2,1,"not started"
2,3,"in progress"
you will also need additional Courses table like this
courserId,courseName
1, math
2, programming
3, networking
and a students table
students
1 "john smith"
2 "perry clam"
3 "john deere"
etc..you could also optionally create a status table to store the distinct statusstrings statusstings and refer to their PK instead ofthestrings
studentID,courseID,status
1,1,1
1,2,2
2,1,2
2,3,3
... etc
and status table
id,status
1,"completed"
2,"not started"
3,"in progress"
the beauty of this representation is: it is quite easy to filter and aggregate data , i.e it is easy to query which subjects a particular person have completed, how many subjects are completed by an average student, etc. this things are much more difficult in the columnar design like you had. you can also easily add new subjects without the need to adapt your tables or even queries they,will just work.
you can also always usin SQLs PIVOT query to get it to a familiar columnar presentation like
name,mathstatus,programmingstatus,networkingstatus,etc..
but now 5 rows are required
No, it's still just one row. That row simply contains identifiers for values stored in other tables.
There are pros and cons to this. One of the main reasons to normalize in this way is to protect the integrity of the data. If a column is just a string then anything can be stored there. But if there's a foreign key relationship to a table containing a finite set of values then only one of those options can be stored there. Additionally, if you ever want to change the text of an option or add/remove options, you do it in a centralized place.
Moving the data from the old table to this new table seems to be not an easy task.
No problem at all. Create your new numeric columns on the data table and populate them with the identifiers of the lookup table records associated with each data table record. If they're nullable, you can make them foreign keys right away. If they're not nullable then you need to populate them before you can make them foreign keys. Once you've verified that the data is correct, remove the old de-normalized columns. Done.
In StudentCourseCompletionStatus1 you still need 2 associations to Status and CourseStatusType. So I think you should consider following variant of normalization:
It means, that your StudentCourseCompletionStatus would hold only one CourseStatusID and another table CourseStatus would hold the associations to CourseType and Status.
To move your data you can surely use a query.

PostgreSQL force X amount of foreign key rows after insert

If I have the following tables:
CREATE TABLE projects
(
id SERIAL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
);
INSERT INTO projects (name) VALUES ('Portfolio Website'), ('Client Website');
CREATE TABLE developers
(
id SERIAL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
);
INSERT INTO developers (name) VALUES ('Kevin'), ('Mark'), ('Simon');
CREATE TABLE languages
(
id SERIAL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
);
INSERT INTO languages (name) VALUES ('HTML'), ('PHP'), ('ASP.NET'), ('Java');
CREATE TABLE developer_languages
(
id SERIAL PRIMARY KEY,
developer INTEGER REFERENCES developers(id),
language INTEGER REFERENCES languages(id)
);
INSERT INTO developer_languages (developer, language) VALUES (1,1), (1,2), (2,1), (2,3), (3,4);
CREATE TABLE project_developers
(
id SERIAL PRIMARY KEY,
project INTEGER REFERENCES projects(id),
developer INTEGER REFERENCES developers(id)
);
The requirement is that every project has a HTML developer and a Java developer. Is there any way to create a rule that enforces this?
I know I could just have a 'html_dev' and 'java_dev' column in the projects table but this then is an extra data source if you wanted to get every developer on the project stored in these two columns and the project_developers table.
I hope my question makes sense? I'm not even sure where to start looking so I though someone might be able to point me in the right direction, thanks!
What you are trying to do is not easily solved and a constraint trigger is not the solution because you cannot create a constraint to match your problem. One solution is the following, although it is a bit artificial:
Remove the INSERT privilege from the projects table.
Create a function insert_new_project(nm text, html_dev integer, java_dev integer) which inserts the new project and two inserts in project_developers. Check that the developers indeed have the required language skills.
Remove the UPDATE privilege on project_developers. Create a BEFORE DELETE trigger on project_developers to check that if you delete a Java or HTML developer from a project there is at least one such developer remaining. (So if you want to remove a developer, first insert a replacement.)
This procedure ensures that a new project has one developer of both flavours and that when developers get removed from a project at least one of each flavour remains. Insert a new project with SELECT insert_new_project('New project', 1, 3);.