banCharField

Diagnostic Category: lint/safety/banCharField

Since: vnext

Sources: - Inspired from: squawk/ban-char-field

Description

Using CHAR(n) or CHARACTER(n) types is discouraged.

CHAR types are fixed-length and padded with spaces, which can lead to unexpected behavior when comparing strings or concatenating values. They also waste storage space when values are shorter than the declared length.

Use VARCHAR or TEXT instead for variable-length character data.

Examples

Invalid

CREATE TABLE "core_bar" (
    "id" serial NOT NULL PRIMARY KEY,
    "alpha" char(100) NOT NULL
);

code-block.sql:1:1 lint/safety/banCharField ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! CHAR type is discouraged due to space padding behavior.

  > 1 │ CREATE TABLE "core_bar" (
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^
  > 2 │     "id" serial NOT NULL PRIMARY KEY,
  > 3 │     "alpha" char(100) NOT NULL
  > 4 │ );
      │ ^^
    5 │ 

  i CHAR types are fixed-length and padded with spaces, which can lead to unexpected behavior.

  i Use VARCHAR or TEXT instead for variable-length character data.

Valid

CREATE TABLE "core_bar" (
    "id" serial NOT NULL PRIMARY KEY,
    "alpha" varchar(100) NOT NULL
);

How to configure

{
  "linter": {
    "rules": {
      "safety": {
        "banCharField": "error"
      }
    }
  }
}