Question

I have a precision problem storing a float value in mysql via jpa (EclipseLink). In my code I have annotated the field with

@Column(precision=15, scale=7)
private float x;

But when i store a value like 322,249878 the database returns 322.25. Whats going on there :)?

Answer 1

precision and scale settings are only applicable to exact numeric types (i.e. BigDecimal in Java and decimal in MySQL).

Floating point types (float and double) are approximate by their nature, therefore these settings don’t make sense for them.

Also note that if you change type of this field to BigDecimal you should initialize it with precise values as well.