auto-increment

问题 Since CouchDB does not have support for SQL alike AUTO_INCREMENT what would be your approach to generate sequential unique numeric ids for your documents? I am using numeric ids for: User-friendly IDs (e.g. TASK-123, RQ-001, etc.) Integration with libraries/systems that require numeric primary key I am aware of the problems with replication, etc. That's why I am interested in how people try to overcome this issue. 回答1: As Dominic Barnes says, auto-increment integers are not scalable, not

问题 Is there a way to set mysql's auto_increment to a certain integer in an "ad hoc" way - for example, N of the latest rows have been deleted in a table, so the primary key/auto_increment is N off from the actual # of rows? Is there a way to set the auto_increment to the right number, or to manually set it? This seems common, so I believe it has been asked already, but I've not been able to find a solution, other than that this isn't possible or you shouldn't do it. 回答1: ALTER TABLE tablename

问题 Is there a way to set mysql's auto_increment to a certain integer in an "ad hoc" way - for example, N of the latest rows have been deleted in a table, so the primary key/auto_increment is N off from the actual # of rows? Is there a way to set the auto_increment to the right number, or to manually set it? This seems common, so I believe it has been asked already, but I've not been able to find a solution, other than that this isn't possible or you shouldn't do it. 回答1: ALTER TABLE tablename

问题 Is there a way to set mysql's auto_increment to a certain integer in an "ad hoc" way - for example, N of the latest rows have been deleted in a table, so the primary key/auto_increment is N off from the actual # of rows? Is there a way to set the auto_increment to the right number, or to manually set it? This seems common, so I believe it has been asked already, but I've not been able to find a solution, other than that this isn't possible or you shouldn't do it. 回答1: ALTER TABLE tablename

问题 I have a table and it's first column sl is auto incrementing. After populating my table, I removed first two rows, and the first entry is having sl 1. Is it possible to reset it to 1 maintaining AI? I am using PHP MyAdmin. 回答1: I'm not sure if i got your question but if you want your column sl to be renumbered do ALTER TABLE your_table DROP sl and then ALTER TABLE your_table ADD sl your_definitions 回答2: ALTER TABLE tablename AUTO_INCREMENT = 1; 回答3: If you just want to reset the auto-number

问题 I have a lot of tables and because of some reasons I need to adjust auto increment value for this tables on application startup. I try to do this: mysql> select max(id) from item; +----------+ | max(id) | +----------+ | 97972232 | +----------+ 1 row in set (0.05 sec) mysql> alter table item auto_increment=1097972232; In another session: afrolov@A1-DB1:~$ mysql -u root -e "show processlist" | grep auto_increment 472196 root localhost test Query 39 copy to tmp table alter table item auto

问题 I have table in Database and the primry key is 'ID', Just I want to ask how can I make it AUTOINCREMENT I know that's esay Q, but I dont know how can I do it. thanks 回答1: There is a property "Identity Specification". Expand that one, you can chose Increment value, and Increment Seed 回答2: In Sql Server define the column like this... [PrimaryID] [int] IDENTITY(1,1) NOT NULL Then you can add a constraint making it the primary key. 回答3: MySQL: http://dev.mysql.com/doc/refman/5.0/en/example-auto

问题 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 (

问题 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 (

问题 Wondering if there is a shorthand version to insert a new record into a table that has the primary key enabled? (i.e. not having to include the key column in the query) Lets say the key column is called ID, and the other columns are Fname, Lname, and Website $query = "INSERT INTO myTable VALUES ('Fname', 'Lname', 'Website')"; 回答1: Use the DEFAULT keyword: $query = "INSERT INTO myTable VALUES (DEFAULT,'Fname', 'Lname', 'Website')"; Also, you can specify the columns, (which is better practice):