auto-increment

问题 Anyone know how to create a table with a surrogate key? looking for something like autoincrement, that is just a large integer that automatically adds the next highest unique number as the primary key. Need to know how to create the table as well as how to add records (preferably through scraperwiki.sqlite.save) Thanks! 回答1: This seems to work for me for the specific case, if not answering the more general one https://scraperwiki.com/scrapers/autoincr_demo Bonuses include not having to

问题 I am in the process of upgrading a Rails 2.3.4 project to Rails 3.1.1. The old version used ar-extensions to handle a data import. I pulled out ar-extensions and replaced it with activerecord-import, which I understand has exactly the same interfaces. My code calls looks like this Student.import(columns, values) Both args are valid arrays holding the correct data, but I get a big fat error! The error stack looks like this: NoMethodError (You have a nil object when you didn't expect it! You

问题 I have created a table in APEX that has a PK that is incremented by a SQL sequence: CREATE SEQUENCE seq_increment MINVALUE 1 START WITH 880 INCREMENT BY 1 CACHE 10 This seems to work perfectly. The issue is that sometimes, usually when I get on in the morning and run a process to enter a new row, it skips a bunch of numbers. I only care because these numbers are being used as the ID# of documents in my company and losing/skipping blocks of numbers is not going to be acceptable when this tool

问题 I am using the Informix.NET driver (C#) to insert a row into a database table. This works fine, except I have no idea how to get the ID of the last inserted row: Insert Command: //Sample Query: "INSERT INTO names (id, name) values (0, 'John Smith');" public static void Insert(String query) { try { using (IFX::IfxConnection connection = ConnectionManager.GetConnection()) { connection.Open(); using (IFX::IfxCommand command = new IFX::IfxCommand(query, connection)) command.ExecuteNonQuery(); if

问题 I need to create a table that will contain a incremental id, but I would like the ids be automatically segmented according to an other column. Here is what I want : CREATE TABLE dbo.MyTable ( myKey INT IDENTITY PRIMARY KEY, category INT, incrementalId INT ); INSERT INTO dbo.MyTable (category) VALUES (100); INSERT INTO dbo.MyTable (category) VALUES (200); INSERT INTO dbo.MyTable (category) VALUES (100); INSERT INTO dbo.MyTable (category) VALUES (100); INSERT INTO dbo.MyTable (category) VALUES

问题 I ran a comparison INSERTing rows into an empty table using MySQL 5.6. Each table contained a column ( ascending ) that was incremented serially by AUTO_INCREMENT, and a pair of columns ( random_1 , random_2 ) that receive random, unique numbers. In the first test, ascending was PRIMARY KEY and ( random_1 , random_2 ) were KEY. In the second test, ( random_1 , random_2 ) were PRIMARY KEY and ascending was KEY. CREATE TABLE clh_test_pk_auto_increment ( ascending_pk BIGINT UNSIGNED NOT NULL

问题 NEW VERSION (not new problem...) So, i got a "loop" problem with a .click(); and a .html(); . Retrieve XML datas: OK function afficher(NomPizz, Prix1, Prix2, Prix3) {//HERE IS MY CODE//}); Print them to screen: OK $('#pricecontainer').show(); //Display my container and put values in with .html(); $('#prix1').html('SOLO 1P<p id="p1" style="line-height:10px;">' + Prix1.toFixed(2) + '</p>'); $('#prix2').html('MAXI 2P<p id="p2" style="line-height:10px;">' + Prix2.toFixed(2) + '</p>'); $('#prix3')

问题 I've got several tables in a database, let's say they're called table1, table 2, etc. All tables have a primary key column 'id' with auto-increment. In my current configuration it happens that when inserting into table1, the generated id is 1. Afterwards when inserting into table2, the generated id happens to be 1 as well. How to force absolutely unique ids across all tables in a database? I want when inserting into table1, generated id to be 1, and if afterwards inserting into table2,

问题 Basically what I want is a working-version of the following code: ALTER TABLE table_name AUTO_INCREMENT = ( SELECT `AUTO_INCREMENT` FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'database_name' AND TABLE_NAME = 'another_table_name' ); The error: 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AUTO_INCREMENT = The reason: According to MySQL Doc: InnoDB uses the in-memory auto-increment counter

问题 I'm trying to get a function to increment alphas upwards in PHP from say A->ZZ or AAA -> ZZZ with all the variations in between, ie. A, B, C...AA, AB, AC..ZX, ZY, ZZ etc.. The following code works sometimes, but then breaks in certain instances, this example works perfectly. $from = "A"; $to = "ZZ"; while(strnatcmp($from, $to) <= 0) { echo $from++; } While this does not work as expected. $from = "A"; $to = "BB"; while(strnatcmp($from, $to) <= 0) { echo $from++; } Output is: First: A B C D ..