SQL: set existing column as Primary Key in MySQL

mysql sql indexing primary-key
krasatos picture krasatos · Mar 14, 2012 · Viewed 136.1k times · Source

I have a database with 3 columns: 

id, name, somethingelse

This table has no index set and i am getting "No index defined!" in phpmyadmin
id is a 7digit alphanumeric value, unique to each row.
I want to set Drugid to be the primarykey/index (i dont know the difference if there is one)
Please explain in detail as i am new to this.
Thank you.

Answer

ypercubeᵀᴹ picture ypercubeᵀᴹ · Mar 14, 2012

Either run in SQL:

ALTER TABLE tableName
  ADD PRIMARY KEY (id)           ---or Drugid, whichever you want it to be PK

or use the PHPMyAdmin interface (Table Structure)

Related questions

Indexes and multi column primary keys

Went searching and didn't find the answer to this specific noob question. My apologies if I missed it. In a MySQL database I have a table with the following primary key PRIMARY KEY id (invoice, item) In my application I …

Read More
How to hint the index to use in a MySQL select query?

I have a MySQL query (running MySQL 5.0.88), which I'm trying to speed up. The underlying table has multiple indices and for the query in question, the wrong index is used (i_active - 16.000 rows, vs. i_iln - 7 rows). I'm …

Read More
Two single-column indexes vs one two-column index in MySQL?

I'm faced with the following and I'm not sure what's best practice. Consider the following table (which will get large): id PK | giver_id FK | recipient_id FK | date I'm using InnoDB and from what I understand, it creates indices …

Read More