Mysql 多列的唯一约束

Question

I have this table and, as the code shows, I have marked columns " cnpj, product, proposalNumber " as a unique composed constraint:

    @Table(name = "Proposal", uniqueConstraints = {@UniqueConstraint(columnNames = {"cnpj", "product", "proposalNumber"})})
    public class Proposal {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id", unique = true, updatable = false, insertable = false)
        @JsonProperty("id")
        private Long id;
    
        @JsonProperty("cnpj")
        @Column(name = "cnpj", nullable = false, length = 14)
        private String cnpj;
    
        @JsonProperty("proposalNumber")
        @Column(name = "proposalNumber", nullable = false)
        private String proposalNumber;
    
        @JsonProperty("product")
        @Column(name = "product", nullable = false, length = 100)
        private String product;
    
        @JsonProperty("price")
        @Column(name = "price", nullable = false)
        private BigDecimal price;
    
        @JsonProperty("dueDate")
        @Column(name = "dueDate", nullable = false)
        private String dueDate;
    
        @JsonProperty("qtyLife")
        @Column(name = "qtyLife", nullable = false)
        private Integer qtyLife;
    
        @JsonIgnore
        @Column(name = "active", nullable = false)
        private Boolean active = true;

        ...

But, checking the DDL or DUMP ain't no unique information...

CREATE TABLE `proposal` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `active` bit(1) NOT NULL,
  `cnpj` varchar(14) NOT NULL,
  `due_date` varchar(255) NOT NULL,
  `price` decimal(19,2) NOT NULL,
  `product` varchar(100) NOT NULL,
  `proposal_number` varchar(255) NOT NULL,
  `qty_life` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

In addition to this, writing @Column(unique = true) on the column does not solve the problem either, it creates the unique constraint in the database but only referencing that single column, not the composition ( cnpj, product and proposalNumber ).

Any tips?

Answer 1

The problem is solved: nothing wrong with my solution, but I had to change my spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect to spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect