SQLite外键错误

Question

我刚开始学习JDBC，这里发生了一个问题。我有桌子医生和病人。它们已成功创建，其中包含自己的ID，但我无法创建以下表：

String sqlVisit = "CREATE TABLE IF NOT EXISTS Visit (" +
       "id INTEGER PRIMARY KEY NOT NULL," +
       "doctor_id INTEGER NOT NULL," +
       "FOREIGN KEY (doctor_id) REFERENCES Doctor (id)," +
       "patient_id INTEGER NOT NULL," +
       "FOREIGN KEY (patient_id) REFERENCES Patient (id),"+
       "cost DOUBLE NOT NULL," +
       "date DATE" +
       ")";

错误行：

org.sqlite.SQLiteException: [SQLITE_ERROR] SQL error or missing database (near "patient_id": syntax error)

我不知道我做错了什么，试图找到解决方案，但没有成功。