auto-increment

问题 I\'m coming from MySQL world, please help. Is it possible to create autoincrement key from NetBeans IDE in JavaDB? Do you use some more advanced db clients, which? Thanks. 回答1: Found a way of setting auto increment in netbeans 8.0.1 here on StackoOverflow Screenshot below: 回答2: This may help you: CREATE TABLE "custinf" ( "CUST_ID" INT not null primary key GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1), "FNAME" VARCHAR(50), "LNAME" VARCHAR(50), "ADDR" VARCHAR(100), "SUBURB"

问题 I have a table with existing data. Is there a way to add a primary key without deleting and re-creating the table? 回答1: ( Updated - Thanks to the people who commented ) Modern Versions of PostgreSQL Suppose you have a table named test1 , to which you want to add an auto-incrementing, primary-key id (surrogate) column. The following command should be sufficient in recent versions of PostgreSQL: ALTER TABLE test1 ADD COLUMN id SERIAL PRIMARY KEY; Older Versions of PostgreSQL In old versions of

问题 I am trying to insert from one table into another using DECLARE @IDOffset int; SELECT @IDOffset = MAX(ISNULL(ID,0)) FROM TargetTable INSERT INTO TargetTable(ID, FIELD) SELECT [Increment] + @IDOffset ,FeildValue FROM SourceTable WHERE [somecondition] TargetTable.ID is not an identity column, which is why I have to find a way to auto-increment it myself. I know I can use a cursor, or create a table variable with an identity column and a FieldValue field, populate that, then use it in my insert

问题 Here is a table in MySQL 5.3.X+ db: CREATE TABLE members` ( `id` int(11) UNSIGNED NOT NULL AUTO_INCREMENT, `memberid` VARCHAR( 30 ) NOT NULL , `Time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP , `firstname` VARCHAR( 50 ) NULL , `lastname` VARCHAR( 50 ) NULL , UNIQUE (memberid), PRIMARY KEY (id) ) ENGINE = MYISAM; Id column is never used in queries, it is just for visual convenience (so it\'s easy to see how the table grows). Memberid is an actual key, is unique, and memberid is used in

问题 I have a pre-existing table, containing \'fname\', \'lname\', \'email\', \'password\' and \'ip\'. But now I want an auto-increment column. However, when I enter: ALTER TABLE users ADD id int NOT NULL AUTO_INCREMENT I get the following: #1075 - Incorrect table definition; there can be only one auto column and it must be defined as a key Any advice?:) 回答1: Try this ALTER TABLE `users` ADD `id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY 回答2: If you don't care whether the auto-id is used as PRIMARY

问题 I want to loop through a collection of objects and add them all to a table. The destination table has an auto-increment field. If I add a single object there is no problem. If I add two objects both with the primary key of zero, the entity framework fails. I can manually specify primary keys but the whole point of trying the EF was to make life easier not more complicated. Here is the code and the exception received follows. foreach (Contact contact in contacts) { Instructor instructor =

问题 What are the other ways of achieving auto-increment in oracle other than use of triggers? 回答1: As far as I can recall from my Oracle days, you can't achieve Auto Increment columns without using TRIGGER. Any solutions out there to make auto increment column involves TRIGGER and SEQUENCE (I'm assuming you already know this, hence the no trigger remarks). 回答2: You can create and use oracle sequences. The syntax and details are at http://www.techonthenet.com/oracle/sequences.php Also read the

问题 I would like to force the auto increment field of a table to some value, I tried with this: ALTER TABLE product AUTO_INCREMENT = 1453 AND ALTER SEQUENCE product RESTART WITH 1453; ERROR: relation \"your_sequence_name\" does not exist I\'m new to postgres :( I have a table product with Id and name field 回答1: If you created the table product with an id column, then the sequence is not simply called product , but rather product_id_seq (that is, ${table}_${column}_seq ). This is the ALTER

问题 I\'ve read some posts about this but none cover this issue. I guess its not possible, but i\'ll ask anyway. I have a table with more than 50.000 registers. It\'s an old table where various insert/delete operations have taken place. That said, there are various \'holes\' some of about 300 registers. I.e.: ..., 1340, 1341, 1660, 1661, 1662, ... The question is. Is there a simple/easy way to make new inserts fill these \'holes\'? thx Paulo Bueno 回答1: What is the reason you need this

问题 A co-worker just made me aware of a very strange MySQL behavior. Assuming you have a table with an auto_increment field and another field that is set to unique (e.g. a username-field). When trying to insert a row with a username thats already in the table the insert fails, as expected. Yet the auto_increment value is increased as can be seen when you insert a valid new entry after several failed attempts. For example, when our last entry looks like this... ID: 10 Username: myname ...and we