Can't use String as #Id with SpringData - mysql

Question

I want to create new table on my database using this class
#Entity
#Table(name = "currency_rate")
public class CurrencyRate {
#Id
private String id;
#Column(name = "source_currency")
private String sourceCurrency;
#Column(name = "target_currency")
private String targetCurrency;
#Column(name = "exchange_rate")
private double exchangeRate;
#Column
private Date date;
#PrePersist
public void generateID() {
this.id = this.date.toString().replace("-", "") + sourceCurrency + targetCurrency;
}
//getters, setters
}
When I try to run my application with property
spring.jpa.hibernate.ddl-auto=create
I got this exception
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:
Specified key was too long; max key length is 1000 bytes
Looks like I can't use Spring as my ID? Changing type to Long solves problem, but I really wanted to go with String with this one. From what I searched, it should be totally doable.

Answer 1

As per tutorial from https://www.tutorialspoint.com/hibernate/hibernate_annotations.htm, the attribute can be defined by Column annotation in details.
#Column Annotation The #Column annotation is used to specify the
details of the column to which a field or property will be mapped. You
can use column annotation with the following most commonly used
attributes −
name attribute permits the name of the column to be explicitly
specified.
length attribute permits the size of the column used to map a value
particularly for a String value.
nullable attribute permits the column to be marked NOT NULL when the
schema is generated.
unique attribute permits the column to be marked as containing only
unique values.
What matters here for your question is length parameter, maybe you can try annotate your id like below:
#Id
#Column(length = 100)
private String id;