no-implicit-join · eslint-plugin-postgresql

Why this matters

`SELECT ... FROM a, b WHERE ...` is an implicit cross join whose join condition is buried in `WHERE`. Forget the condition and you silently get a cartesian product. Explicit `JOIN ... ON ...` puts the join condition next to the join.

Examples

Incorrect

SELECT a.id FROM a, b WHERE a.id = b.id;

Correct

SELECT a.id FROM a JOIN b ON a.id = b.id;

Configure it

// eslint.config.js
import postgresql from "eslint-plugin-postgresql";

export default [
  {
    files: ["**/*.sql"],
    languageOptions: {
      parser: postgresql.configs.recommended.languageOptions.parser,
    },
    plugins: { postgresql },
    rules: {
      "postgresql/no-implicit-join": "warn",
    },
  },
];

Options

This rule has no options.

Edit the SQL — only no-implicit-join is enabled.

Pre-filled with the first incorrect example. Toggle off in the rule shelf to see how the diagnostic disappears.

Diagnostics

No issues found.

2 rules enabled.

Rule under test no-implicit-join — plus no-syntax-error as a safety net.