Unique Key Constraint in Spring Data Jpa

Question

How to make a field unique in pojo using spring data jpa?I know how to do that using jpa

For reference: multi column constraint with jpa

If there is a way, is it possible to use with spring boot?

Rahul · Answer 1 · 2017-03-16T16:00:47.430

15

Use the @UniqueConstraint annotation to specify that a unique constraint is to be included in the generated DDL for a primary or secondary table.

Alternately, to ensure a field value is unique you can write

@Column(unique=true)
String myField;

edited Mar 16 '17 at 16:00

answered Mar 16 '17 at 15:54

Rahul

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Thanks. What's the package of `UniqueConstraint`? – AlikElzin-kilaka Jun 29 '22 at 06:13

score 2 · Answer 2 · answered Mar 16 '17 at 06:29

2

With Spring Data JPA you are using JPA, so you specify the unique constraint using JPA. Nothing special from Spring Boot or Spring Data on that front.

answered Mar 16 '17 at 06:29

Jens Schauder

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So you are saying we need to use jpa only to make it as unique constraint.Nothing in the spring data jpa – Karthikeyan Soundararaj Mar 16 '17 at 07:24
is this corect? – Karthikeyan Soundararaj Mar 16 '17 at 14:40

score 1 · Answer 3 · answered Feb 28 '20 at 11:53

If you have a single column in the table that has UNIQUE KEY constraint then you can simply add the attribute unique=true in the annotation @Column

CODE SNIPPET:

@Column(name = "unique_key_field", nullable = false, unique = true)
String uniqueKeyFied;

In case if you have multiple Unique key constraints in the table then you have to simply follow with the JPA annotations as the spring-boot-data-starter does not provide any special annotations for the table constraints(KEY/UNIQUEKEY).

CODE SNIPPET:

@Entity
@Table(name = "table_name", uniqueConstraints={
          @UniqueConstraint( name = "idx_col1_col2",  columnNames ={"col1","col2"})
       })

score 0 · Answer 4 · answered Mar 08 '19 at 12:27

Um exemplo em Kotlin:

Entity
@Table(name = "TBL_XXX",
    uniqueConstraints = [
            UniqueConstraint(name = "sessionid_uindex", columnNames = ["sessionId"])
    ]
)
data class XxxReturn(
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "XXX_ID")
    var id: Long? = null,

    var sessionId: String,

    var msg: String
)

Unique Key Constraint in Spring Data Jpa

4 Answers4