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For a DB there are 4 columns that represent numbers:

col1 type: NUMBER(38)
col2 type: NUMBER(18) 
col3 type: NUMBER(10,2)

In Spring JPA should I map these columns to Float or Double ?

@Column(name = "col1")
private Double col1

@Column(name = "col2")
private Double col2

@Column(name = "col3")
private Double col3

or

@Column(name = "col1")
private Float col1

@Column(name = "col2")
private Float col2

@Column(name = "col3")
private Float

Is it redundant to use Double as each number type

col1 type: NUMBER(38)
col2 type: NUMBER(18) 
col3 type: NUMBER(10,2)

can be mapped to float without loss of precision ?

Update:

For NUMBER(38) should be ? :

@Column(precision=38, scale=0)

For NUMBER(10,2) should be ? : 

@Column(precision=10, scale=2)
blue-sky
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  • You mean this - https://stackoverflow.com/questions/4078559/how-to-specify-doubles-precision-on-hibernate and this - https://www.tutorialspoint.com/hibernate/hibernate_mapping_types.htm? – Ajay Kumar Apr 05 '20 at 19:51
  • @AjayKumar please see question update. – blue-sky Apr 05 '20 at 19:55
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    Why not use `BigDecimal` together with the precision and scale values for the `@Column` annotation? – Matthew Formosa Apr 05 '20 at 20:19
  • @Matthew Formosa I plan to use Long, why BigDecimal instead of Long ? For NUMBER(38) Long is suitable with precision=38 ? – blue-sky Apr 05 '20 at 20:23
  • Yes, sure. However, if you're concerned about loss of precision with the other fields, I would definitely opt for `BigDecimal`. – Matthew Formosa Apr 05 '20 at 20:30
  • Having said that it could be the case that `Long` would not be able to store `NUMBER(38)` given its size so be careful. For such a use case there's `BigInteger` which might be a more suitable option. – Matthew Formosa Apr 05 '20 at 20:33
  • @Matthew Formosa Double is also an option instead of BigInteger? – blue-sky Apr 05 '20 at 20:43
  • It's an option but I would not go for `Double` given that you are not dealing with decimals in this case. – Matthew Formosa Apr 05 '20 at 20:48
  • Since NUMBER(38) and NUMBER(10,2) are huge, you can use Double for both. (Double should be capable of handling more precision in future if you need it). – Ajay Kumar Apr 06 '20 at 05:08

0 Answers0