Creating a composite type with "char"?

All we need is an easy explanation of the problem, so here it is.

PostgreSQL has a type called char that’s stored as an signed 1 byte int

The type "char" (note the quotes) is different from char(1) in that it only uses one byte of storage. It is internally used in the system catalogs as a simplistic enumeration type.

Can we create composite types with "char"? I can create a table with it…

CREATE TABLE pixel ( r "char", g "char", b "char" );

Internally that creates a type which I can use elsewhere,

CREATE TABLE f ( mypixel pixel );

But, can I create a simple TYPE (no table) from it?

CREATE TYPE pixel ( r "char", g "char", b "char" );
ERROR:  syntax error at or near ""char""
LINE 1: CREATE TYPE pixel ( r "char", g "char", b "char" );

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

It’s just the missing keyword AS:

CREATE TYPE pixel AS (r "char", g "char", b "char");

The data type "char" is a non-standard type, primarily meant for internal purposes. But it’s just another type – except for the peculiar spelling of the name including the double-quotes to disambiguate against char. See:

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

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