Postgresql unique index multiple columns
Note that only B-tree indexes can be declared as unique indexes. When you define an UNIQUE index for a column, the column cannot store multiple rows with the ...,When you add a UNIQUE constraint to a column or a group of columns, PostgreSQL will automatically create a unique index on the column or the group of columns.,You can do that in pure SQL. Create a partial unique index in addition to the one you have: CREATE UNIQUE INDEX ab_c_null_idx ON my_table (id_A, ...,When an index is declared unique, multiple table rows with equal indexed values are not allowed. Null values are not considered equal. A multicolumn unique ...,An index can be defined on more than one column of a table. ... The only reason to have multiple BRIN indexes instead of one multicolumn BRIN index on a ...,Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ...,Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ...,When an index is declared unique, multiple table rows with equal indexed values are not allowed. Null values are not considered equal. A multicolumn unique ...,Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ...,2013年1月8日 — Create unique constraint that two numbers together CANNOT together be repeated: ALTER TABLE someTable ADD UNIQUE (col1, col2).
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 Postgresql unique index multiple columns 相關參考資料
PostgreSQL UNIQUE Index
Note that only B-tree indexes can be declared as unique indexes. When you define an UNIQUE index for a column, the column cannot store multiple rows with the ... https://www.postgresqltutorial PostgreSQL UNIQUE Constraint
When you add a UNIQUE constraint to a column or a group of columns, PostgreSQL will automatically create a unique index on the column or the group of columns. https://www.postgresqltutorial PostgreSQL multi-column unique constraint and NULL values
You can do that in pure SQL. Create a partial unique index in addition to the one you have: CREATE UNIQUE INDEX ab_c_null_idx ON my_table (id_A, ... https://dba.stackexchange.com Documentation: 9.1: Unique Indexes - PostgreSQL
When an index is declared unique, multiple table rows with equal indexed values are not allowed. Null values are not considered equal. A multicolumn unique ... https://www.postgresql.org Documentation: 9.6: Multicolumn Indexes - PostgreSQL
An index can be defined on more than one column of a table. ... The only reason to have multiple BRIN indexes instead of one multicolumn BRIN index on a ... https://www.postgresql.org Documentation: 12: 11.6. Unique Indexes - PostgreSQL
Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ... https://www.postgresql.org Documentation: 13: 11.6. Unique Indexes - PostgreSQL
Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ... https://www.postgresql.org Documentation: 9.0: Unique Indexes - PostgreSQL
When an index is declared unique, multiple table rows with equal indexed values are not allowed. Null values are not considered equal. A multicolumn unique ... https://www.postgresql.org Documentation: 11: 11.6. Unique Indexes - PostgreSQL
Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows. PostgreSQL ... https://www.postgresql.org In Postgresql, force unique on combination of two columns
2013年1月8日 — Create unique constraint that two numbers together CANNOT together be repeated: ALTER TABLE someTable ADD UNIQUE (col1, col2). https://stackoverflow.com |