I am creating a table which is like this:
CREATE TABLE Peeps
(
Name VARCHAR(255) NOT NULL,
PhoneNum BIGINT NOT NULL,
CONSTRAINT PhoneNum_Check CHECK (PhoneNum LIKE '08%')
)
Every phone number has to start with 08. However when I tried insert there's an error because LIKE can't be used for numeric (or that's what my friend said). The alternative would be using VARCHAR for PhoneNum, but this is an assignment and we have to use numeric for the phone number.
If a phone number can start with a 0 then you need to use a string:
CREATE TABLE Peeps (
Name VARCHAR(255) NOT NULL,
PhoneNum VARCHAR(255) NOT NULL,
CONSTRAINT PhoneNum_Check CHECK (PhoneNum LIKE '08%')
);
Although you can use LIKE on a number, it is highly not recommended. What happens is that the number is converted to a string. However, that string will never start with a 0 -- well, at least never when the value is greater than 1.
Related
The code is the category of the video, it is represented by one upper case character, excluding I, O,
Q, V, Y and Z, followed by a numeric character.
So far, I took a guess and got this. Any suggestions on how to fix it?
create table channelTable (
channelID number NOT NULL,
ChannelName varchar(100) NOT NULL,
ChannelDate date NOT NULL,
UserName varchar(100) NOT NULL UNIQUE,
TopicCode varchar(4) NOT NULL);
CONSTRAINT channelID_pk PRIMARY KEY (channelID)
CONSTRAINT c_topicCode LIKE '[A-Za-z][0-9] NOT (I,O,Q,N,Y,Z)
);
Some comments:
NOT NULL is not needed for PRIMARY KEY columns.
In Oracle, use VARCHAR2().
Then, I would suggests regular expressions. If the value is supposed to be exactly two characters, then declare it as such:
create table channelTable (
channelID number,
ChannelName varchar(100) NOT NULL,
ChannelDate date NOT NULL,
UserName varchar2(100) NOT NULL UNIQUE,
TopicCode char(2) NOT NULL;
CONSTRAINT channelID_pk PRIMARY KEY (channelID)
CONSTRAINT check (REGEXP_LIKE(c_topicCode, '^[A-HJ-NPR-UYZ][0-9]$')
);
Or perhaps more simply:
CONSTRAINT REGEXP_LIKE(c_topicCode, '^[A-Z][0-9]$') AND NOT REGEXP_LIKE(c_topicCode, '^[IOQNYZ]'))
All that said, I would rather see a table of TopicCodes that is populated with the correct values. Then you can just use a foreign key relationship to define the appropriate codes.
Use the regular expression ^[A-HJ-MPR-X]\d$ to match an upper-case character excluding I,O,Q,N,Y,Z followed by a digit:
CREATE TABLE channels (
id number CONSTRAINT channel__id__pk PRIMARY KEY,
Name varchar(100) CONSTRAINT channel__name__nn NOT NULL,
DateTime date CONSTRAINT channel__date__nn NOT NULL,
UserName varchar(100) CONSTRAINT channel__username__NN NOT NULL
CONSTRAINT channel__username__U UNIQUE,
TopicCode varchar(4),
CONSTRAINT channel__topiccode__chk CHECK ( REGEXP_LIKE( topiccode, '^[A-HJ-MPR-X]\d$' ) )
);
db<>fiddle
Also, you don't need to call the table channeltable just call it channels and you don't need to prefix the column names with the table name and you can name all the constraints (rather than relying on system generated constraint names which makes it much harder to track down issues when you are debugging).
Consider the following check constrait:
create table channelTable (
...
topicCode varchar(4) not null
check(
substr(c_topicCode, 1, 1) not in ('I', 'O', 'Q', 'V', 'Y', 'Z')
and regexp_like(topicCode, '^[A-Z]\d')
),
...
);
The first condition ensures that the code does not start with one of the forbidden characters, the second valides that it stats with an upper alphabetic character, followed by a number.
To avoid using two conditions, an alternative would be to list all allowed characters in the first position:
check(regexp_like(topicCode, '^[ABCDEFGHJKLMNPRSTUVWX]\d'))
This works in Oracle, and in very recent versions of MySQL.
I am experimenting with PostgreSQL coming from SQL using MySQL and I simply wish to create a table with this piece of code which is valid SQL:
CREATE TABLE flat_10
(
pk_flat_id INT(30) DEFAULT 1,
rooms INT(10) UNSIGNED NOT NULL,
room_label CHAR(1) NOT NULL,
PRIMARY KEY (flat_id)
);
I get the error
ERROR: syntax error at or near "("
LINE 3: pk_flat_id integer(30) DEFAULT 1,
I have conducted searches on the web and found no answer and I cant seem to find an answer in the PostgreSQL manual. What am I doing wrong?
I explicitly want to set a limit to the number of digits that can be inserted into the "pk_flat_id" field
I explicitly want to set a limit to the number of digits that can be inserted into the "pk_flat_id" field
Your current table definition does not impose a "size limit" in any way. In MySQL the parameter for the intdata type is only a hint for applications on the display width of the column when displaying it.
You can store the value 2147483647 in an int(1) without any problems.
If you want to limit the values to be stored in an integer column you can use a check constraint:
CREATE TABLE flat_10
(
pk_flat_id bigint DEFAULT 1,
rooms integer NOT NULL,
room_label CHAR(1) NOT NULL,
PRIMARY KEY (flat_id),
constraint valid_number
check (pk_flat_id <= 999999999)
);
The answer is that you use numeric or decimal types. These are documented here.
Note that these types can take an optional precision argument, but you don't want that. So:
CREATE TABLE flat_10
(
pk_flat_id DECIMAL(30) DEFAULT 1,
rooms DECIMAL(10) NOT NULL,
room_label CHAR(1) NOT NULL,
PRIMARY KEY (pk_flat_id)
);
Here is a SQL Fiddle.
I don't think that Postgres supports unsigned decimals. And, it seems like you really want serial types for your keys and the long number of digits is superfluous.
Changing integer to numeric works.
CREATE TABLE flat_10
(
pk_flat_id bigint DEFAULT 1,
rooms numeric NOT NULL,
room_label CHAR(1) NOT NULL,
);
I am new to MSSQL 2014 Server, my professor listed these steps to make a table, I don't know the proper steps to create tables in the pictures listed below, please help.
Create and populate (insert values) the following tables per table description and data values provided
DEPARTMENT
EMPLOYEE
PROJECT
ASSIGNMENT
Add a SQL Comment to include /* * Your First Name_Your Last Name* */ when inserting corresponding values for each table.
What I tried so far:
CREATE TABLE DEPARTMENT(
DepartmentName Text(35) PRIMARY KEY,
BudgetCode Text(30) NOT NULL,
OfficeNumber Text(15) NOT NULL,
Phone Text(12) NOT NULL, );
I have put this to my query and the error is
Msg 2716, Level 16, State 1, Line 1 Column, parameter, or variable #1: Cannot specify a column width on data type text.
Try this(I assume that your table exists in dbo schema):
IF OBJECT_ID(N'dbo.DEPARTMENT', N'U') IS NOT NULL
BEGIN
DROP TABLE DEPARTMENT
END
GO
CREATE TABLE DEPARTMENT(
DepartmentName varchar(35) PRIMARY KEY,
BudgetCode varchar(30) NOT NULL,
OfficeNumber varchar(15) NOT NULL,
Phone varchar(12) NOT NULL
);
You can not define width for Text data type. In case which you need to define width you can use char or varchar data types. Also keep in mind that if you need to work with Unicode characters then you will need to use nchar or nvarchar instead.
so i was trying to make a code for a document. So if i put 01234567890 and 1234567890 on a table, they should stay there. But when i put 12345667890 and then look the table, that number is different like: 1234566789 (the zero is gone!)
Plus the length must be 11.
If you can help me/understand me, thank you.
create table DOCTORS(
fullname varchar(35) not null,
document varchar(11) not null,
salary bigint null,
homeaddress varchar(35) null,
phone bigint not null,
cellphone bigint not null,
speciality varchar(20) not null,
birthdate date not null,
gradedate date not null,
workingdate date not null,
constraint pk primary key (document) and check(document between '0' and '99999999999'),
constraint validCellphone check (cellphone between 3000000000 and 3029999999 or cellphone between 3100000000 and 3129999999 or cellphone between 3150000000 and 3169999999),
constraint validSpeciality check (speciality in('Medicina general','Ginecologia','Traumatologia','Pediatria')),
constraint validDates check (birthdate < gradedate and birthdate < workingdate and gradedate< getdate() and workingdate< getdate() and gradedate<workingdate),
constraint antiquity check (datediff(dd, gradedate, getdate() )>1461),
constraint validPhone check(phone between 1000000 and 9999999)
);
GO>
If you tried INT previously,
01234567890
is not a number. It's a string.
1234567890
is the number.
SQL is able to recognize that those extra zeros are not needed to define the number, so it ignores them. If you want to dispaly a value as 01234567890 to the application, I'd suggest doing the formatting on the application side. That way the number stored in SQL is still a number if you want do addition, aggregation, or other calculations. If you really have to store it as '01234567890', you need to convert it to a character field; char, varchar, nvarchar, nchar.
Maybe not literally but the query below gets an error near user. If i change it to userZ it works. WHY can i not use that name? Is there a way to specific its a field instead of a keyword? (or whatever it is)
create table Post2 (
id INTEGER PRIMARY KEY NOT NULL,
title nvarchar(max)
NOT NULL,
body nvarchar(max)
NOT NULL,
user integer REFERENCES Post1(id));
Reserved words, like user should be enclosed in brackets.
Take a look at Using Identifiers for a more in depth explanation.
CREATE TABLE Post2 (
id INTEGER PRIMARY KEY NOT NULL
, title NVARCHAR(MAX)NOT NULL
, body NVARCHAR(MAX) NOT NULL
, [User] INTEGER REFERENCES Post1(id)
);
USER is a reserved word.
Try delimiting it with "" (e.g. "user" or [user])
Read more on using delimited identifiers here.