Can anybody tell me how to create columns with space like "FULL NAMES"?
I've tried like the following but it doesn't work.
CREATE TABLE info
(
Full Names varchar(20),
Physical Address varchar(20),
Moviesrented varchar(100),
Salutation varchar(20),
Category varchar(20),
PRIMARY KEY (address)
)
Just put the name in backticks:
CREATE TABLE info (`Full Names` varchar(20), ...)
But that's no good handle for naming your columns.
I wonder why you want that. But to answer your question, wrap it with backticks.
`Full Names` VARCHAR(20)
Related
Can anybody tell me how to create columns with space like "FULL NAMES"?
I've tried like the following but it doesn't work.
CREATE TABLE info
(
Full Names varchar(20),
Physical Address varchar(20),
Moviesrented varchar(100),
Salutation varchar(20),
Category varchar(20),
PRIMARY KEY (address)
)
Just put the name in backticks:
CREATE TABLE info (`Full Names` varchar(20), ...)
But that's no good handle for naming your columns.
I wonder why you want that. But to answer your question, wrap it with backticks.
`Full Names` VARCHAR(20)
Hi guys so i dont know how to make it as varchar because is want to input BSIT as my primary key and i cant figure it out how to make it as characters please help me this is my code btw
create table CourseTBL
(
CourseID int primary key,
Course varchar(50),
Description varchar(50),
)
It's better to create a different CODE column to use WHERE condition on it, because key is something meaningless and is intended for referential integrity only. For PK add a constraint as an another element of CREATE TABLE statement. Like this:
create table CourseTBL
(
CourseID varchar(50),
Course varchar(50),
Description varchar(50),
primary key( CourseID )
)
My preference is to add course code column
Create table CourseTBL
(
CourseID int primary key,
CourseName varchar(50),
CourseCode varchar(10),
CourseDescription varchar(50),
)
So I got used to using doctrine so much that I forgot the standard mysql syntax, which I need for an exam.
I want to create a test database called 'youtube'
with an app_users table and an app_videos table.
In "real life" this would be a oneToMany relationship, but I need to
study to create a manyToMany relationship.
so its
"many app_users" -> have "many app_videos"
and the other way around.
so first I created a database;
CREATE DATABASE youtube;
use youtube;
then I created the users and videos table
CREATE TABLE app_users(
id INT AUTO_INCREMENT,
username VARCHAR(20),
password VARCHAR(40),
first_name VARCHAR(20),
last_name VARCHAR(20),
video_id INT,
PRIMARY KEY(id)
);
CREATE TABLE app_videos(
id INT AUTO_INCREMENT,
video_path VARCHAR(20),
description VARCHAR(20),
likes INT(20),
dislikes INT(20),
user_id INT,
PRIMARY KEY(id)
);
then I created a relationship table
CREATE TABLE vid_uid
(
id INT AUTO_INCREMENT,
video_id INT,
user_id INT,
PRIMARY KEY(id)
);
now what I need to do is somehow connect the columns to eachother but my syntax never works
I know I need to change this
ALTER TABLE app_users
ADD FOREIGN KEY(video_id)
REFERENCES app_videos(video_id);
to something that works :/
You need to change app_videos(video_id) to app_videos(id). Also you want to alter the table vid_uid (not app_users) since thats the one that as references to external keys:
ALTER TABLE vid_uid
ADD FOREIGN KEY(video_id)
REFERENCES app_videos(id);
You'll also need to do:
ALTER TABLE vid_uid
ADD FOREIGN KEY(user_id)
REFERENCES app_users(id);
I am a beginner at this but is it possible (in MySQL workbench) to create an attribute that is a set depended on an attribute from another table?
CREATE TABLE danes (
id INT PRIMARY KEY,
name VARCHAR(50),
nationality VARCHAR(20),
gender CHAR(1),
degree SET ?????????????????? from degree(level)
);
CREATE TABLE degree (
level VARCHAR(10),
subject VARCHAR(20),
institutionawarding VARCHAR(20),
yearawarded DATE,
PRIMARY KEY (level, subject)
);
never mind I got it
I am guessing that you want another table, a junction table:
CREATE TABLE DaneDegrees (
DanesId INT REFERENCES danes(id),
Level VARCHAR(10),
Subject VARCHAR(20),
FOREIGN KEY fk_level_subject(level, subject) REFERENCES Degree(level, Subject)
);
I would, however, have an INT AUTO_INCREMENT PRIMARY KEY in both Danes and Degrees.
apparently you cant just say
<attribute_name> set(get set from another tabe)
the set thing doesn't work that way
eventhough you can apparently update it so it actually can
update table_name
attribute = (select * from another table_name)
I have two tables classroom and computer and currently computer is a variable in the table classroom
CREATE TABLE classroom_tbl
(
room_id INT AUTO_INCREMENT PRIMARY KEY,
teacher_name VARCHAR(30),
subject_name VARCHAR(30),
computer VARCHAR(30)
);
and I want to make it so instead of being a VARCHAR in the classroom table the variable computer calls the computer table
CREATE TABLE computer_tbl
(
computer_id INT AUTO_INCREMENT PRIMARY KEY,
computer_type VARCHAR(30),
computer_status INT
);
Is there any way to do this? I've tried UNION and INNER JOIN but I always get an error that says that my columns are different sizes. Which makes sense because classroom is bigger than computer. Thanks for any help you can give!
I believe you are new to SQL and have some experience in programming. SQL does not have variables like we do have in programming langauages such as C/C++/java. Rather SQL tables relate to each other with relationships such as foreign key relationship. You need to go through SQL tutorials for understanding more about relationships, here is a link to one of those:
http://www.functionx.com/sql/Lesson11.htm
In order to use the JOINS you need to have Primary-foreign key relationship between the two tables. You may have to create your table like this:
CREATE TABLE classroom_tbl
(
room_id INT AUTO_INCREMENT PRIMARY KEY,
teacher_name VARCHAR(30),
subject_name VARCHAR(30),
computer_id INT REFERENCES computer_tbl(computer_id)
);
Since a given classroom can have many computers in it, but a given computer can only be in one classroom at a time, it makes more sense to have classroom as a foreign key on the computer table, rather than vice versa:
CREATE TABLE classroom_tbl
(
room_id INT AUTO_INCREMENT PRIMARY KEY,
teacher_name VARCHAR(30),
subject_name VARCHAR(30)
);
CREATE TABLE computer_tbl
(
computer_id INT AUTO_INCREMENT PRIMARY KEY,
computer_type VARCHAR(30),
computer_status INT,
room_id INT
);
To see which computers are in each room, try a query like:
select r.room_id, r.teacher_name, r.subject_name,
c.computer_id, c.computer_type, c.computer_status
from classroom_tbl r
left join computer_tbl c on r.room_id = c.room_id
If anyone comes across this, what I wanted to do was not possible. You can only reference other columns in other tables or create foriegn keys. Unfortunatly you cannot reference an entire table.