auto-increment

Could someone explain to me why a PostgreSQL table created with the following scripts: CREATE TABLE users ( "id" serial NOT NULL, "name" character varying(150) NOT NULL, "surname" character varying (250) NOT NULL, "dept_id" integer NOT NULL, CONSTRAINT users_pkey PRIMARY KEY ("id") ) gets dumped by pg_dump in the following format: CREATE TABLE users( "id" integer NOT NULL, "name" character varying(150) NOT NULL, "surname" character varying (250) NOT NULL, "dept_id" integer NOT NULL ); ALTER TABLE users OWNER TO postgres; CREATE SEQUENCE "users_id_seq" START WITH 1 INCREMENT BY 1 NO MINVALUE NO

Is there a way in postgresql to have an auto-incrementing column reset back to zero at a specified time every day? It could be pretty trivial with a cronjob 0 0 * * * echo "SELECT setval('public.my_table_id_seq', 1, false)" | psql -U my_db_user -d my_db_name Alternately, you could set your "serial" column DEFAULT to call a stored procedure, which would check for a day rollover, reset the sequence if appropriate, and then return the result of nextval(). But other than that, no, I wouldn't expect that there's a magic ALTER SEQUENCE my_seq RESET AT INERVAL '1 day' or anything like that. Edit:

I would like to make Postgres choose the first next available id so that no error occurs in the following case: CREATE TABLE test( id serial PRIMARY KEY, name varchar ); Then: INSERT INTO test VALUES (2,'dd'); INSERT INTO test (name) VALUES ('aa'); INSERT INTO test (name) VALUES ('bb'); This will give a constraint error since id is primary. How can I tell Postgres to insert the record with the next free id? Erwin Brandstetter Generally it's best to never overrule the default in a serial column. If you sometimes need to provide id values manually, replace the standard DEFAULT clause nextval(

I saw someone not set the length in a tutorial but it was specifically for counting the total number of users and just set to auto-increment. I've been of the habit of always specifying a length because I thought it was mandatory, but I wanted to ask if I can leave it blank unless it specifically a date or pin number etc where the length is always set. (I used to set it as 11 digits or more if I wasn't sure) Every integer field defaults to 11 when left blank so you can leave it. No, you don't have to specify a length for integers. I have never done that. There are different integral data types

I have a table with an auto-increment ID field as shown below. +------------+-------------------------------------+ | company_id | name | +------------+-------------------------------------+ | 1 | International Client | | 2 | Oracle | | 3 | test | | 4 | testabc | | 5 | testdef | | 6 | abcd | +------------+-------------------------------------+ I want to update the ID column to be a GUID using the uuid() function. Additionally, how do I update the foreign key references to the correct GUID? Use triggers. CREATE TABLE `tbl_test` ( `GUID` char(40) NOT NULL, `Name` varchar(50) NOT NULL, PRIMARY

MySQL CREATE TABLE `role` ( `id_role` INT(11) unsigned NOT NULL AUTO_INCREMENT, PRIMARY KEY (`id_role`) ) AUTO_INCREMENT=1; Hibernate @Entity public class Role { private Integer idRole; @Column(name = "id_role", precision = 10) @GeneratedValue @Id public Integer getIdRole() { return idRole; } public void setIdRole(Integer idRole) { this.idRole = idRole; } } Given the above background, who is responsible of the auto-incrementation of the id_role column when creating a new role ? In other words, does Hibernate set the primary key value before running the create SQL statement, or does it set it

I am designing table in SQL Server 2008 R2 SP2 Express database. I created table with nvarchar column for data and tinyint column for auto-incrementing identity assuming there will be no more than few rows (that's why I choose 0-255 tinyint ). When I add more than 255 rows, this error keeps occurring permanently even after I delete all rows in that table and try to add one new row. I am doing this using SQL Server Management Studio Express. How to force database engine to check what indexes are free? Will this happen too if I change tinyint to int and reach limit of int number? Once you add

I have a table to make temporary id`s . When i delete all of the rows of my table , auto increment value for this table will reset to 0 . but i don't want to reset the auto increment. What can i do? Compare TRUNCATE TABLE : Any AUTO_INCREMENT value is reset to its start value. This is true even for MyISAM and InnoDB, which normally do not reuse sequence values. ... with DELETE FROM : If you delete the row containing the maximum value for an AUTO_INCREMENT column, the value is not reused for a MyISAM or InnoDB table. If you delete all rows in the table with DELETE FROM tbl_name (without a WHERE