SQL: Comments

Welcome to the Comments lesson!

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In SQL, comments begin with --. This is an unusual syntax for comments, although it is shared with some other programming languages, like Ada and Haskell. Anything from the -- until the end of the line gets ignored.

exec(`
  CREATE TABLE cats (
    name TEXT
    -- owner_name TEXT
  )
`);
exec(`INSERT INTO cats (name, owner_name) VALUES ('Wilford', 'Wilford')`);

Result:

Error: table cats has no column named owner_name

SQL databases also support C-style comments /* like this */, which can span multiple lines.

exec(`
  CREATE TABLE cats (
    id INTEGER PRIMARY KEY
    /*
    name TEXT,
    owner_name TEXT
    */
  )
`);
exec(`INSERT INTO cats (name, owner_name) VALUES ('Wilford', 'Wilford')`);

Result:

Error: table cats has no column named name