Common task

Set Default value

• @Column(columnDefinition = "varchar(255) default 'John Snow'")
• Inside Entity class
• private String firstName = "John Snow";

constraint - Nullable

• @Column(nullable=t/f)
• @Basic(optional=t/f)
• hibernate validator - @NotNull
• can apply on any bean, not just entity eg:jackson.

Constraint - unique

• @Column(unique=t/f) : Single column
• unique composite key:

  @Table(uniqueConstraints = {
     @UniqueConstraint(columnNames = { "personNumber", "isActive" }) ,
     @UniqueConstraint(columnNames = { "personNumber" }) 
   }, ...)