auto-increment

I am currently having problems with a primary key ID which is set to auto increment . It keeps incrementing ON DUPLICATE KEY . For Example: ID | field1 | field2 1 | user | value 5 | secondUser | value 86 | thirdUser | value From the description above, you'll notice that I have 3 inputs in that table but due to auto increment on each update, ID has 86 for the third input. Is there anyway to avoid this ? Here's what my mySQL query looks like: INSERT INTO table ( field1, field2 ) VALUES (:value1, :value2) ON DUPLICATE KEY UPDATE field1 = :value1, field2 = :value2 And here's what my table looks

I have a MySQL database which contains a table of users. The primary key of the table is 'userid', which is set to be an auto increment field. What I'd like to do is when I insert a new user into the table is to use the same value that the auto increment is creating in the 'userid' field in a different field, 'default_assignment'. e.g. I'd like a statement like this: INSERT INTO users ('username','default_assignment') VALUES ('barry', value_of_auto_increment_field()) so I create user 'Barry', the 'userid' is generated as being 16 (for example), but I also want the 'default_assignment' to have

In a Postgres 9.3 table I have an integer as primary key with automatic sequence to increment, but I have reached the maximum for integer . How to convert it from integer to serial ? I tried: ALTER TABLE my_table ALTER COLUMN id SET DATA TYPE bigint; But the same does not work with the data type serial instead of bigint . Seems like I cannot convert to serial ? Erwin Brandstetter serial is a pseudo data type, not an actual data type. It's an integer underneath with some additional DDL commands executed automatically: Create a sequence (with matching name by default). Set the column NOT NULL

I'm trying to make a blog system of sort and I ran into a slight problem. Simply put, there's 3 columns in my article table: id SERIAL, category VARCHAR FK, category_id INT id column is obviously the PK and it is used as a global identifier for all articles. category column is well .. category. category_id is used as a UNIQUE ID within a category so currently there is a UNIQUE(category, category_id) constraint in place. However, I also want for category_id to auto-increment . I want it so that every time I execute a query like INSERT INTO article(category) VALUES ('stackoverflow'); I want the

I have a table Messages with columns ID (primary key, autoincrement) and Content (text). I have a table Users with columns username (primary key, text) and Hash. A message is sent by one Sender (user) to many recipients (user) and a recipient (user) can have many messages. I created a table Messages_Recipients with two columns: MessageID (referring to the ID column of the Messages table and Recipient (referring to the username column in the Users table). This table represents the many to many relation between recipients and messages. So, the question I have is this. The ID of a new message

I have a table with an auto_increment field and sometimes rows get deleted so auto_increment leaves gaps. Is there any way to avoid this or if not, at the very least, how to write an SQL query that: Alters the auto_increment value to be the max(current value) + 1 Return the new auto_increment value? I know how to write part 1 and 2 but can I put them in the same query? If that is not possible: how do I "select" (return) the auto_increment value or auto_increment value + 1? Renumbering will cause confusion. Existing reports will refer to record 99, and yet if the system renumbers it may