java errno:150“外键约束格式不正确EdmySQL

Question

我有两张表格，名字是patient_info和report。但当我尝试创建这两个表时，只创建了patient_info，而不创建report table。它显示以下错误。为什么会这样？ JAVAsql。SQLException:无法创建表sampathreport（错误号：150“外键约束格式不正确”）

MySql代码：

private static final String patient_info="CREATE TABLE patient_info(Id_person int(11) NOT null AUTO_INCREMENT,"+
        "ref varchar(10),first_name varchar(100),"+
        "last_name varchar(100),age int(5) not null,"+
        "dob date,address varchar(255),status varchar(20),sample varchar(20),report_no varchar(100),"+
        "primary key(Id_person,report_no))";

private static final String report="CREATE TABLE report(report_no varchar(100),"+
        "Id_person int(11) not null,"+
        "sample varchar(100),report varchar(100),"+
                "foreign key(report_no) references patient_info(report_no) ON DELETE CASCADE ON UPDATE CASCADE)";