-- AlterTable
ALTER TABLE `Contract` ADD COLUMN `previousContractNumber` VARCHAR(191) NULL,
    ADD COLUMN `previousCustomerNumber` VARCHAR(191) NULL,
    ADD COLUMN `previousProviderId` INTEGER NULL;

-- AddForeignKey
ALTER TABLE `Contract` ADD CONSTRAINT `Contract_previousProviderId_fkey` FOREIGN KEY (`previousProviderId`) REFERENCES `Provider`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;