item_name: also manually entered as a variable string.item_category: manually entered as a variable string, too.item_type: manually entered as a variable string.item_number: generated using auto-increment.In the example throughout this article, your table will need to include the following fields: In short: you make your life-and database management-easier. You can then use auto-increment in SQL queries to assign values in the primary key column automatically. When you use auto-incremented fields to assign integer values in your databases, you improve your database stability, limit errors caused by changing values, improve performance and uniformity, increase compatibility, and streamline validation. If youвЂ™re creating these primary keys as a composite of table column values, your work is likely slow and cumbersome. Item numbers cannot be duplicated in order to distinguish between each item in your inventory. You need to create a unique item_number for each order placed from today on (think: thousands of orders). Imagine youвЂ™re working with product data for the inventory of a new solar panel manufacturer and distributor. Intro: auto-incrementing fields and primary keys Insert auto-incremented values for new items.Create a table with auto-incrementing IDs.Intro: auto-incrementing fields and primary keys.

Sql alter table add primary key