auto-increment

I have a 100 million rows, and it's getting too big. I see a lot of gaps. (since I delete, add, delete, add.) I want to fill these gaps with auto-increment. If I do reset it..is there any harM? If I do this, will it fill the gaps?: mysql> ALTER TABLE tbl AUTO_INCREMENT = 1; Potentially very dangerous, because you can get a number again that is already in use. What you propose is resetting the sequence to 1 again. It will just produce 1,2,3,4,5,6,7,.. and so on, regardless of these numbers being in a gap or not. Update: According to Martin's answer, because of the dangers involved, MySQL will

For a particular table, I have my ID field set to AutoNumber (Increment). If I add 5 rows to this table in quick succession, is each guaranteed to have a larger ID than the last? For instance, does autonumbering ever restart from 1 if some earlier values have been deleted? The only time I have ever had trouble with Access autonumbers is when, in error, I set the value of an autonumber key field to a number lower than the current maximum using an append query. Gaps had been created in the numbering by record deletions. Access allows you to force a value into an autonumber field, and sometimes

I am trying to make a column in a mysql database that auto increments by one but goes from 0-Z and then rolls. For example 000, 001, 002, ..., 009, 00A, 00B, ..., 00Z, 010, ..., 0ZZ, ..., 100. I would like to have the database create the column through an auto incrementing field. The ideas I have are: Create a column for each character that goes from 0-36, then auto increment row N (where N is the least significant digit) by 1. Then add a trigger on each column to add 1 to column N-1 when column N reaches 36. Create a table with 36 rows where each row contains a character 0-Z and pull the

Is it possible to create primary key without auto_increment flag in ActiveRecord ? I can't do create table :blah, :id => false because I want to have primary key index on the column. I looked up documentation but didn't find anything useful. Is it possible to create primary key without auto_increment? Try this? create_table(:table_name, :id => false) do |t| t.integer :id, :options => 'PRIMARY KEY' end Blake Miller Okay, the question is old and the OP did not specify versions. None of the answers given here worked for me with these versions: mysql2 0.3.11 rails 3.2.13 mysql 5.5 I ended up going

I basically want to convert a table from mysql to sqlite with the following scheme: create table items ( id integer auto_increment, version integer default 0, primary key (id, version) ); Essentially, I want ID to auto increment whenever I insert anything into the table, with VERSION starting off at 0, but still allow multiple items with the same ID as long as VERSION is different. I'm trying to replicate this behavior with Sqlite however, I can't seem to get table creation working. It seems like you are only allowed one column as autoincrement and it has to be the primary key. If I make ID

How do I change the amount auto_increment fields in MySQL increment by from the default (1) to n? If you want to change autoincrement step from 1 to N then there is a solution. It could be done on MySQL server side: look for '--auto-increment-increment' startup option or use following command SET @@auto_increment_increment=2; , but be warned that this is a server wide change (all tables will increment by 2). Unortodox solutions could that could be considered: Launch two MySQL servers on same machine, with different ports (one with auto_increment_increment=1 other with auto_increment_increment

I have a table in SQLite: CREATE TABLE "EventType" ( [EventTypeID] INTEGER PRIMARY KEY, [EventTypeName] VARCHAR(50) NOT NULL UNIQUE ); Since EventTypeID is an integer and a primary key, that automatically makes it an auto-incrementing column, and that works fine. I'd like to insert a row into the table and get the newly incremented value from VB6. Dim oRs as Recordset dim oCmd as new Command oCmd.ActiveConnection = GetConnection() oCmd.Source = "insert into EventType (EventTypeName) values ('blah')" oCmd.Execute Is there an automatic way to retrieve the newly created EventTypeID without having

How do I auto increment a value stored in Firebase from an Android client? Currently: I declare int id = 1 . When I increment, I see the values 2, 3 etc. being stored. That's fine, but when I re-run the project, id is set equal to 1 again. I want it to behave like a static variable, so I can create an id which will go from 1 to infinity without resetting. UPDATED FAILED I used the following to pass the Firebase reference and a string to the function incrementCounter. if(language_chosen.equalsIgnoreCase("english")) { Firebase publRef = f.child("Language").child("English").child("Message");

I have a strange problem with mysql. I am trying to alter a table's column which is a primary key and has an auto_increment constraint defined on it. This is also a foreign key reference for multiple other tables. I need to change the length of this column in both , parent and all children. set foreign_key_checks=0; alter table Parent modify Identifier smallint(10) unsigned; alter table Child_1 modify FK_Identifier smallint(10) unsigned; alter table Child_2 modify FK_Identifier smallint(10) unsigned; alter table Child_3 modify FK_Identifier smallint(10) unsigned; alter table Child_4 modify FK