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Available in versions: Dev (3.21) | Latest (3.20) | 3.19 | 3.18 | 3.17 | 3.16 | 3.15 | 3.14 | 3.13 | 3.12 | 3.11

Unique constraints

Applies to ✅ Open Source Edition   ✅ Express Edition   ✅ Professional Edition   ✅ Enterprise Edition

A candidate key that is not ideal for a Primary key should still be declared UNIQUE to enforce uniqueness, as well as for query performance reasons. In jOOQ, this can be done with the following approaches: 

// Create a new table with columns and unnamed constraints
create.createTable("table")
      .column("column1", INTEGER)
      .column("column2", INTEGER)
      .column("column3", INTEGER)
      .constraints(
          unique("column1"),
          unique("column2", "column3")
      )
      .execute();

// Create a new table with columns and named constraints (recommended if you want to alter the constraint)
create.createTable("table")
      .column("column1", INTEGER)
      .column("column2", INTEGER)
      .column("column3", INTEGER)
      .constraints(
          constraint("uk1").unique("column1"),
          constraint("uk2").unique("column2", "column3")
      )
      .execute();

Dialect support

This example using jOOQ:

createTable("table")
      .column("column1", INTEGER)
      .constraints(
          constraint("uk").unique("column1")
      )

Translates to the following dialect specific expressions:

Access, DB2, Firebird, Hana, Teradata

CREATE TABLE table (
  column1 integer,
  CONSTRAINT uk UNIQUE (column1)
)

ASE, Sybase

CREATE TABLE table (
  column1 int NULL,
  CONSTRAINT uk UNIQUE (column1)
)

Aurora MySQL, Aurora Postgres, Derby, DuckDB, Exasol, H2, HSQLDB, MariaDB, MemSQL, MySQL, Postgres, Redshift, SQLServer, SQLite, Vertica, YugabyteDB

CREATE TABLE table (
  column1 int,
  CONSTRAINT uk UNIQUE (column1)
)

BigQuery

CREATE TABLE table (
  column1 int64
)

ClickHouse

CREATE TABLE table (
  column1 Nullable(integer)
)
ENGINE Log()

CockroachDB

CREATE TABLE table (
  column1 int4,
  CONSTRAINT uk UNIQUE (column1)
)

Databricks

CREATE TABLE table (
  column1 int,
  CONSTRAINT uk UNIQUE (column1)
)
TBLPROPERTIES(
  'delta.columnMapping.mode' = 'name',
  'delta.feature.allowColumnDefaults' = 'supported'
)

Informix

CREATE TABLE table (
  column1 integer,
  UNIQUE (column1) CONSTRAINT uk
)

Oracle, Snowflake

CREATE TABLE table (
  column1 number(10),
  CONSTRAINT uk UNIQUE (column1)
)

SQLDataWarehouse

CREATE TABLE table (
  column1 int,
  CONSTRAINT uk UNIQUE (column1) NOT ENFORCED
)

Trino

CREATE TABLE table (
  column1 int
)
Generated with jOOQ 3.21. Support in older jOOQ versions may differ. Translate your own SQL on our website

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