如何在Postgresql数据库中创建具有一列枚举数据类型的表？

Question

How can I create a table with one column of enum datatype in PostgreSQL database?

Table name: Employee

Columns:

ID: Integer

Name: ENUM

Below is the query but not sure it is correct or not.

CREATE TYPE Name AS ENUM();

CREATE TABLE IF NOT EXISTS Employee(
    ID integer NOT NULL,
    Name DEFAULT NULL,
    CONSTRAINT "Employee_pkey" PRIMARY KEY (id)
 );

Can someone please help.

Answer 1

Here you got a simple example, consider to add a name to your enum column at Employee Table, and add some values to your enum.

 CREATE TYPE NameEnum AS ENUM('Jony','Bala','Mark');

 CREATE TABLE IF NOT EXISTS Employee(
    ID integer NOT NULL,
    name NameEnum DEFAULT NULL,
    CONSTRAINT "Employee_pkey" PRIMARY KEY (id)
 );

 Insert into Employee(ID,name)
 Values(1,  (SELECT enum_first(NULL::NameEnum)))

 Select * from Employee
 Output:

Answer 2

1. In the line

Name DEFAULT NULL,

you either forgot the name of the column or defining the columns as enum type:

myname Name DEFAULT NULL, -- add column name

or

Name Name DEFAULT NULL, -- add enum type

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2. Because "Name" is a keyword in Postgres you also have to change the type name. Otherwise it will not work.

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3. However: Your enum type has no values. So you are not able to insert any value. You have to add some enum values:

 CREATE TYPE name_type AS ENUM('name1', 'name2'); 

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Final:

 CREATE TYPE name_type AS ENUM('name1', 'name2'); CREATE TABLE Employee2( ID integer, myname name_type ); 

demo: db<>fiddle