Table example :
Table T1(
ID int primary key,
n1 int
)
How can I add a trigger to check if n1 is between 0 and 10 before inserting?
Answer by #500-InternalServerError (will delete if they post):
There is no need for a trigger. Use a CHECK constraint instead.
CREATE TABLE Persons (
ID int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int CHECK (Age>=18)
);
db<>fiddle
Related
The task indicated this:
Create a table named automagic with the following fields:
An id field is an auto-incrementing serial field.
A name field that allows up to 32 characters but no more This field is required.
A height field is a floating-point number that is required.
And my code was:
CREATE TABLE automatic (
id SERIAL PRIMARY KEY NOT NULL,
name CHAR (32),
height numeric);
However, the self-rater answered this Expecting an INSERT without a height to fail, it did not fail.
After that, I tried this
CREATE TABLE automatic (
id int not null auto_increment primary key,
name varchar(32) not null,
height float not null);
And got
ERROR: syntax error at or near "auto_increment"
LINE 1: CREATE TABLE automagic (id int not null auto_increment prima...\
SQL state: 42601
Character: 41
You can try something like this:
CREATE TABLE automagic (
id int NOT NULL,
name varchar(32) NOT NULL,
height float NOT NULL
);
CREATE SEQUENCE automagic_id_seq
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
ALTER SEQUENCE automagic_id_seq OWNED BY automagic.id;
ALTER TABLE ONLY automagic ALTER COLUMN id SET DEFAULT nextval('automagic_id_seq'::regclass);
EDIT:
As pointed out by #a_horse_with_no_name, this is better:
CREATE TABLE automagic (
id int GENERATED ALWAYS AS IDENTITY,
name varchar(32) NOT NULL,
height float NOT NULL
);
maybe try this:
CREATE TABLE automagic (
id SERIAL,
name VARCHAR(32) NOT NULL,
height FLOAT NOT NULL)
Use primary key.
CREATE TABLE automagic (
id SERIAL primary key,
name VARCHAR(32) NOT NULL,
height FLOAT NOT NULL)
I am trying to make a simple database with an number generator but why do I get the error below?
ERROR: syntax error at or near "AUTO_INCREMENT"
LINE 2: IDNumber int NOT NULL AUTO_INCREMENT,
Code:
CREATE TABLE Finance
(
IDNumber int NOT NULL AUTO_INCREMENT,
FinName varchar(50) NOT NULL,
PRIMARY KEY(IDNumber)
);
The subject of the question mentions pgAdmin 4, so here's how to do it there.
First, add a column to your table, then click the little edit icon:
Then go to Constraints and select the Identity type:
This generates SQL similar to this:
CREATE TABLE public.my_table_name
(
id integer NOT NULL GENERATED ALWAYS AS IDENTITY,
PRIMARY KEY (id)
);
For Postgres you have to use SERIAL
CREATE TABLE Finance
(
IDNumber SERIAL PRIMARY KEY,
FinName varchar(50) NOT NULL
);
IN pgadmin-2.
step 01:
create seq:
and set info:
step 02: go to ID in table and set constraints
if it is sql the syntax is the following
CREATE TABLE Persons (
ID int IDENTITY(1,1) PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int
);
You are using a MySQL syntax which won't work in SQL Server.
CREATE TABLE Finance
(
IDNumber int NOT NULL IDENTITY(1,1) PRIMARY KEY,
FinName varchar(50) NOT NULL
);
The following code should work for SQL Server.
IDENTITY(1,1) is SQL Server's way of saying "auto increment".
The starting value for IDENTITY is 1, and it will increment by 1 for each new record.
So : IDENTITY(startvalue, incrementvalue)
there are two options; one is to use the "datatype" serial or create a sequence and use this sequence as a default value for your integer as follows:
CREATE SEQUENCE your_seq;
CREATE TABLE foo(
id int default nextval('your_seq'::regclass),
other_column TEXT);
INSERT INTO foo(other_column) VALUES ('bar') RETURNING *;
It is important to note that specifying a table as follows:
CREATE TABLE tablename (
colname SERIAL);
is equivalent to:
CREATE SEQUENCE tablename_colname_seq AS integer;
CREATE TABLE tablename (
colname integer NOT NULL DEFAULT nextval('tablename_colname_seq'));
ALTER SEQUENCE tablename_colname_seq OWNED BY tablename.colname;
More information about serial can be found here.
I have data I want to looking to design table as in the picture
Create a table with the following design
CREATE TABLE dbo.MyData
(
SeqNo INT IDENTITY(1,1) CONSTRAINT Pk_MyDate_SeqNo PRIMARY KEY,
Diseases VARCHAR(255),
YesNo BIT CONSTRAINT Df_MyData_YesNo DEFAULT(0),
Duration INT,
Treatement VARCHAR(255)
)
Insert the value 1 To the Column YesNo for value Yes for No insert Value 0
I wanna create a table in SQL, and if the I wanna set the attributes to NULL, how do I do it?
For example, I wanna create a table named Courses and its attributes "CourseNo" and "Title" must not be null. I created one below:
CREATE TABLE Courses(
CourseNo INTEGER CHECK(100<=CourseNo<=999) PRIMARY KEY,
Title VARCHAR(100),
)
ALTER TABLE Courses
ALTER COLUMN CourseNo INTEGER NOT NULL
ALTER COLUMN Title VARCHAR(100) NOT NULL
Is this correct?
whatever you wrote that one correct but good practice is to write not null at a time of defining table. do like this:
CREATE TABLE Courses(
CourseNo INTEGER CHECK(100<=CourseNo<=999) PRIMARY KEY,
Title VARCHAR(100) NOT NULL,
)
primary key is by default NOT NULL always, hence you no need to declare it as NOT NULL
NOT NULL in alter is used when u want to make change in column definations of table later
Change that Title VARCHAR(100) to Title VARCHAR(100) NOT NULL.
CREATE DATABASE agom COLLATE Arabic_CI_AS
CREATE TABLE Branches
(
ID INT PRIMARY KEY NOT NULL IDENTITY,
NAME VARCHAR(255) NOT NULL
)
CREATE TABLE agom.Brands
(
ID INT PRIMARY KEY NOT NULL IDENTITY,
NAME VARCHAR(255) NOT NULL
)
CREATE TABLE agom.Work_Order
(
NUMBER INT NOT NULL,
BRANCHID INT NOT NULL,
BRANDID INT NOT NULL,
WDATE DATE NOT NULL,
REPAIRSTATUS VARCHAR(255),
REPAIRCOST VARCHAR(255),
REMARK VARCHAR(500),
PRIMARY KEY (NUMBER,BRANCHID,BRANDID)
)
CREATE TABLE agom.Profiles
(
ID INT PRIMARY KEY NOT NULL IDENTITY,
USERNAME VARCHAR(25) NOT NULL,
PASS VARCHAR(25) NOT NULL
)
ALTER TABLE agom.Work_Order
ADD CONSTRAINT branchfk
FOREIGN KEY (BRANCHID) REFERENCES Branches(ID)
ALTER TABLE agom.Work_Order
ADD CONSTRAINT brandfk
FOREIGN KEY (BRANDID) REFERENCES Brands(ID)
I get an error that cannot create table
I try to write database name with the table name db.tablename but it's not working
I need to create the database then create the tables and its constraints but I don't know where is the error.I am a sql noob
It's never Database.Table.
It's either Table, or Schema.Table, or Database.Schema.Table, or Server.Database.Schema.Table.
You probably just want to insert USE agom right after create database, and then only refer to tables by name.
Alternatively, you can refer to your tables as agom.dbo.Work_Order, dbo being the default database schema.
See Using Identifiers As Object Names for general reference.