H2 unique constraint However, you can have many UNIQUE constraints per table, but only one ALTER TABLE CUSTOMERS MODIFY AGE INT NOT NULL UNIQUE; You can also use the following syntax, which supports naming the constraint in multiple columns as well. ALTER TABLE CUSTOMERS ADD CONSTRAINT myUniqueConstraint UNIQUE(AGE, SALARY); DROP a UNIQUE Constraint. Each of them would on its own would violate a unique constraint, but when both are applied together, the result should be fine. It is not possible to disable checking for unique constraint. By the logic employed, an index is also a key but only when unique. Jul 5, 2022 · Usually it is more reasonable to create a primary key constraint for id column and a unique constraint for (itinerary_id, user_id), but you may have own reasons for such schema. Alter table add constraint is a command used to add different constraints to the table such as primary key, foreign key, not null, etc. Then: alter table t add col (case when <condition> then -1 else uniqueid end); create unique index unq_t_col on t(col); I believe that H2 supports unique indexes, computed columns, and indexes on computed columns, so this should work. I wrote the following query: execute immediate ('alter table mytable drop constraint ' || QUOTE_IDENT((select "UNIQUE_INDEX_NAME" "INFORMATION_SCHEMA". Dec 21, 2010 · Drop unique constraint in MySQL and H2. Basically MySQL is Feb 25, 2021 · When creating a UNIQUE constraint via the CREATE statement, H2 does not find the constraint when trying to drop it later. g. Alter Table Add Constraint. May 9, 2022 · I'm using H2 as a test db, and Liquibase to initialize it. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. Furthermore, we can have only one primary key constraint per table. To drop a UNIQUE constraint, use the following SQL query. I should obtain a constraint name by quering: select constraint_name from information_schema. Instead of be named as Foobar_pk as clearly specified in CONSTRAINT Foobar_pk PRIMARY KEY (id), it's named CONSTRAINT_F. Simply put, the unique constraints apply in addition to any constraint entailed by primary key mapping. . The required indexes are automatically created if they don’t exist yet. So then we'd start with IK_columnname for unique indexes and IX_columnname for non-unique indexes. I want my primary key constraint and primary key index name same, so that I can get an exception with predefined constraint violation. 0. I feel this makes it safer to manage the constraint later by avoiding ambiguity on use of the name and referencing the name directly defined previously e. Oct 7, 2014 · I try to drop unique constraint for column in h2, previously created as info varchar(255) unique. I saw in another issue here that Hibernate was blamed for not correctly extracting the constraint name from h2 messages, but Hibernate cannot possibly extract the constraint name, because it is not contained in the message. clauses may be optionally specified; after it column constraint(s) may be optionally specified; and collation may be optionally specified after them (H2 doesn't support per-column collations). Try Teams for free Explore Teams May 5, 2019 · databaseChangeLog: - changeSet: id: add-user-unique-constraint author: me changes: - addUniqueConstraint: columnNames: email, delete constraintName: unique-email-not-deleted tableName: users The above naive approach puts a composite constraint on (email, delete) columns, but it doesn't work because in the following flow user is blocked from SQL UNIQUE Constraint. CONSTRAINT_74. Also VARCHAR(36) looks like a some data type for UUID values, H2 has more efficient specialized UUID data type for this purpose. By using a Constaint Name Definition the foreign key is named explicitly, otherwise H2 assigns it a name based on it's own naming scheme e. A PRIMARY KEY constraint automatically has a UNIQUE constraint. This command commits an open transaction in this connection. If CASCADE is specified, unique or primary key constraint is dropped together with all referential constraints that reference the specified constraint. Marvellous. May 23, 2017 · alter table t add col (case when <condition> then -1 else uniqueid end); create unique index unq_t_col on t(col); I believe that H2 supports unique indexes, computed columns, and indexes on computed columns, so this should work. The database is H2. select * from INFORMATION_SCHEMA. I forgot to name that constraint, so a random name was choosen by 2=h2 (or liquibase, doesn't matter). UNIQUE constraint not working on a column in 在本文中，我们将介绍如何在 SQL H2 数据库中使用约束（constraint）来创建表格。约束是一种用于保证数据完整性和一致性的规则。 约束是一种用于保证数据完整性和一致性的规则。 Jul 23, 2018 · After testing the SQL directly on H2 and looking at the catalog, I see something weird with this specific constraint. CREATE TABLE roles ( id int NOT NULL, rolename varchar(255), CONSTRAINT "pk_role_id" PRIMARY KEY (id) ); Jan 28, 2015 · This solution works and, in my opinion, is the healthiest solution Otherwise, we would have to create a constraint outside the table, which is very unhealthy. May 3, 2017 · Currently I can get if the constraints exists with . So I don't think it's a problem with Flyway anymore, and it's just about H2. Example: ALTER TABLE TEST DROP CONSTRAINT UNIQUE_NAME RESTRICT. I've created a table with unique constraint on one column with liquibase. The table is auto-generated. Does anyone have a clue about it? Sep 4, 2023 · While creating tables in h2. 000000,2022-04-23 23:59:59. Having the same constraint names and defining a unique constraint in this way is quite readable and practical. – But PUBLIC. constraints where table_name='PUBLIC_PARTNER' and column_list='INFO'); Removes a constraint or a primary key from a table. CONSTRAINTS WHERE CONSTRAINT_NAME='CURTRP_USER_ID' but how do I build this into a if query with H2. Now I need to drop that constraint, but I have no success. H2 Primary index name auto-generated. Edit: I could move the constraint part in total to the migration script, but this seems somehow wrong. UNIQUE constraint not working on a column in Oct 9, 2019 · I have a Spring Boot application using Spring Data repositories with entities mapped with JPA. ALTER TABLE SET May 28, 2016 · I'm trying to figure out if there's a way to drop a unique constraint using a SQL statement that will work for both MySQL and H2 (setup in MySQL compatibility mode). "CONSTRAINTS" where "TABLE_NAME"='mytable' and "CONSTRAINT_TYPE"='REFERENTIAL'))); Sep 4, 2020 · In the SQL Standard, definition of a column begins with its name immediately followed by data type or domain name; then one of default, identity, generation, etc. MySQL UNIQUE CONSTRAINT failing in CREATE TABLE with subsequent INSERT. 1. Jul 21, 2021 · Is there a way to create a unique case-insensitive index on a column in a H2 table? For what it's worth, I can do this in Postgres with: create unique index unique_name_idx on my_table (UPPER(name)); May 23, 2017 · Let me assume the unique id is numeric and never negative. The UNIQUE constraint ensures that all values in a column are different. Apr 23, 2022 · To ease out reading, these are the values from the above 2 records that are part of unique key constraint: 335640,A,5316,NULL,2022-04-17 00:00:00. The name of the constraint is count_name_key. 000000 Question: Why is NULL in item_id ignored and 2 similar records were allowed to be entered? Mar 5, 2015 · I have the following constraint in CREATE statement: UNIQUE (`field_name`) These commands to remove constraint work in MySQL but not in H2: DROP INDEX `field_name` ON `table_name`; ALTER TABLE `table_name` DROP INDEX `field_name`; I need a command which would work both in MySQL and H2 (MySQL is used in real environment and H2 in Unit tests) May 20, 2022 · I want to drop all the FKs in a H2 (MySQL database) table, as it is described here. May 11, 2024 · Hence, the primary key constraint automatically has a unique constraint. I'm doing two updates in the same transaction. Oct 9, 2019 · I have a Spring Boot application using Spring Data repositories with entities mapped with JPA. However, there can be multiple unique constraints per table. Otherwise it's an index. Dec 21, 2015 · H2 Database Primary Key Violation. When adding the constraint AFTER the CREATE statement it works (as in #570 ). And the only difference between a unique constraint and a unique index is INCLUDE columns. I am working with H2 Database. I tried: sql> alter table public_partner drop constraint (select distinct unique_index_name from in formation_schema. May 9, 2023 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. constraints where The UNIQUE constraint ensures that all values in a column are different. The constraint names must be unique so change this constraintName into something that will be unique You could use a unique index instead and go for "IXU". COUNT_NAME_KEY_INDEX_2 is not the name of the constraint, it's a database-generated name. Perhaps a constraint instead? You can test if datum is limiting you to unqiue values by changing one of the date/times to 12:00 .