TypeScript example from documentation fails with "SequelizeDatabaseError: Duplicate column name 'UserId'"

[TobiasWehrum]

When executing the "Example of a minimal TypeScript project" from http://docs.sequelizejs.com/manual/typescript.html, running sequelize.sync() fails with the following error:

Executing (default): CREATE TABLE IF NOT EXISTS `users` (`id` INTEGER UNSIGNED auto_increment , `name` VARCHAR(128) NOT NULL, `preferredName` VARCHAR(128), `createdAt` DATETIME NOT NULL, `updatedAt` DATETIME NOT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB;
Executing (default): SHOW INDEX FROM `users`
Executing (default): CREATE TABLE IF NOT EXISTS `projects` (`id` INTEGER UNSIGNED auto_increment , `ownerId` INTEGER UNSIGNED NOT NULL, `name` VARCHAR(128) NOT NULL, `createdAt` DATETIME NOT NULL, `updatedAt` DATETIME NOT NULL, PRIMARY KEY (`id`), FOREIGN KEY (`ownerId`) REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE) ENGINE=InnoDB;
Executing (default): SHOW INDEX FROM `projects`
Executing (default): CREATE TABLE IF NOT EXISTS `address` (`id` INTEGER NOT NULL auto_increment , `userId` INTEGER UNSIGNED, `address` VARCHAR(128) NOT NULL, `createdAt` DATETIME NOT NULL, `updatedAt` DATETIME NOT NULL, `UserId` INTEGER UNSIGNED, PRIMARY KEY (`id`), FOREIGN KEY (`UserId`) REFERENCES `users` (`id`) ON DELETE SET NULL ON UPDATE CASCADE) ENGINE=InnoDB;
(node:8856) UnhandledPromiseRejectionWarning: SequelizeDatabaseError: Duplicate column name 'UserId'

As you can see, the address table first creates a userId key and then yet another UserId key (which it then tries to use as a foreign key).

I believe this is in line which what is reported in https://github.com/sequelize/sequelize/issues/3035 and https://github.com/sequelize/sequelize/issues/9328 and I fixed it by replacing

Address.belongsTo(User, { targetKey: "id" });
User.hasOne(Address, { sourceKey: "id" });

with

Address.belongsTo(User, { targetKey: "id", foreignKey: "userId" });
User.hasOne(Address, { sourceKey: "id", foreignKey: "userId" });

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[ephys]

We're resolving these sort of issues in https://github.com/sequelize/sequelize/pull/14280 by introducing the new inverse option. Instead of writing

Address.belongsTo(User, { targetKey: "id" });
User.hasOne(Address, { sourceKey: "id" });

you'll be able to write

Address.belongsTo(User, { targetKey: "id", inverse: { type: 'one' } });

and be guaranteed that the options for both sides of the associations are correct