DROP TABLE users; DROP TABLE domains; CREATE TABLE domains ( "id" BIGSERIAL PRIMARY KEY, "name" varchar(255) UNIQUE NOT NULL ); CREATE INDEX ON domains ("name"); CREATE TABLE users ( "id" BIGSERIAL PRIMARY KEY, "name" varchar(255) NOT NULL, "domain_id" BIGSERIAL NOT NULL, CONSTRAINT "fk_domain" FOREIGN KEY("domain_id") REFERENCES domains("id"), "password" varchar(255) NOT NULL, "redirect" varchar(255) DEFAULT NULL ); CREATE UNIQUE INDEX ON users ("name", "domain_id") WHERE "redirect" IS NULL; INSERT INTO domains (id, name) VALUES (1, 'mails2.sublimity.de'); INSERT INTO users (id, name, domain_id, password) VALUES (1, 'ckn', 1, MD5('test123'));