I need to auto_increment a field in MySQL that is not primary key
Change your current primary key to be a unique key instead: ALTER TABLE table DROP PRIMARY KEY, ADD UNIQUE KEY(username,date); The auto_increment will function …
Would there be a reason not to make primary keys unsigned?
Feb 1, 2018 · You want to flag rows (for some reason) by negating the id. This preserves the value (negate it again to get it back), yet takes it out of the positive range. Caution: In some …
SQL AUTO INCREMENT a Field - W3Schools
AUTO INCREMENT Field. Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table. Often this is the primary key field that we would like …
sql - Making a primary key not "auto-increment" in MySQL
You actually have to specify AUTO INCREMENT or data type SERIAL for it to automatically increment values. If your PRIMARY KEY that will be referenced by this FOREIGN KEY is data …
Auto increment non primary key column in phpMyAdmin
Jul 19, 2017 · The simplest idea is not to assign ‘A_I‘ to this particular column while table creation in phpMyAdmin, instead first set desired column/s as your primary key as required then do as …
MySQL: Why is auto_increment limited to just primary keys?
Jun 23, 2011 · AUTO_INCREMENT is commonly associated with primary keys in MySQL, it's not strictly limited to them. You can use it in other columns as long as the column is part of a …
SQL Server auto increment a column without primary key
Sep 14, 2011 · Declare the column with the IDENTITY keyword, and simply do not create a PRIMARY KEY constraint on it. Is it possible to auto increment a column in SQL Server …
How to Add a Primary Key to an Existing SQL Table - dbvis.com
May 13, 2025 · To add a primary key to an existing table, start by selecting the appropriate column or columns. Clean the data by eliminating duplicates and ensuring there are no NULL …
sql server - AutoIncrement non-primary key or Make unique composite key ...
Dec 26, 2019 · As Vérace suggested, you can do both: create a surrogate (auto-increment) key to simplify joins and related table structures, and add a unique constraint on the two current PK …
MySQL AUTO INCREMENT a Field - W3Schools
Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table. Often this is the primary key field that we would like to be created …
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