關於「MySQL UNIQUE index」標籤，搜尋引擎有相關的訊息討論：

MySQL 8.0 Reference Manual :: 13.1.15 CREATE INDEX StatementSPATIAL and FULLTEXT indexes cannot have functional key parts. If a table contains no primary key, InnoDB automatically promotes the first UNIQUE NOT NULL index ...缺少字詞： gl= twMySQL 5.7 Reference Manual :: 13.1.14 CREATE INDEX StatementA UNIQUE index permits multiple NULL values for columns that can contain NULL . If a table has a PRIMARY KEY or UNIQUE NOT NULL index that consists of a single ...缺少字詞： gl= twMySQL 5.7 Reference Manual :: 13.1.8 ALTER TABLE StatementFor example, you can add or delete columns, create or destroy indexes, change the ... If you add a UNIQUE INDEX or PRIMARY KEY to a table, MySQL stores it ...缺少字詞： gl= twMySQL 5.6 Reference Manual :: 13.1.13 CREATE INDEX StatementThis guideline is especially important for InnoDB tables, where the primary key determines the physical layout of rows in the data file.缺少字詞： gl= twMySQL 5.7 Reference Manual :: 8.3.1 How MySQL Uses IndexesIndexes are used to find rows with specific column values quickly. ... Most MySQL indexes ( PRIMARY KEY , UNIQUE , INDEX , and FULLTEXT ) are stored in ...缺少字詞： gl= twMySQL 8.0 Reference Manual :: 8.3.12 Invisible Indexesmysql> ALTER TABLE t2 ALTER INDEX j_idx INVISIBLE; ERROR 3522 (HY000): A primary key index cannot be invisible. Now suppose that an explicit primary key is ...缺少字詞： gl= tw13.1.18.8 Secondary Indexes and Generated Columns - MySQL ...Secondary indexes that include virtual columns may be defined as UNIQUE . When a secondary index is created on a virtual generated column, generated column ...缺少字詞： gl= twMySQL 5.7 Reference Manual :: 14.13.1 Online DDL OperationsWhen you create a UNIQUE or PRIMARY KEY index, MySQL must do some extra work. For UNIQUE indexes, MySQL checks that the table contains no duplicate values for ...缺少字詞： gl= twConstraints in SQL Server | What is SQL constraints - Great Learning2021年6月8日 · MySQL / SQL Server / Oracle / MS Access: ALTER TABLE Sales ADD UNIQUE(Sale_Id);. To name a UNIQUE constraint, and to define a UNIQUE ...Irv62 manualLink to buy stereo: https://goo.gl/4v4n2O Follow me on Twitter ... Index. Contents. TD 92685EN. Troubleshooting Guide. ... Skyrim se unique followers.