ban-char-field

problem#

Using character is likely a mistake and should almost always be replaced by text or varchar.

From the postgres docs:

There is no performance difference among these three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance advantages in some other database systems, there is no such advantage in PostgreSQL; in fact character(n) is usually the slowest of the three because of its additional storage costs. In most situations text or character varying should be used instead.

https://www.postgresql.org/docs/10/datatype-character.html

See the prefer-text-field rule for info on the advantages of text over varchar.

solution#

Use text or varchar instad of character.

Instead of:

CREATE TABLE "app_user" (
    "id" serial NOT NULL PRIMARY KEY,
    "name" char(100) NOT NULL,
    "email" character NOT NULL,
);

Use:

CREATE TABLE "app_user" (
    "id" serial NOT NULL PRIMARY KEY,
    "name" varchar(100) NOT NULL,
    "email" TEXT NOT NULL,
);