Sql server primary key autoincrement

※ Download: Sql server primary key autoincrement Derek, that's true and that's how I usually do it myself. You can't send private messages. You can't post HTML code. ALTER TABLE ConnDetails ALTER COLUMN ConnNo IDENTIT Y 0 , 1 Msg 156, Level 15, State 1, Line 1 Incorrect syntax near the keyword 'IDENTITY'. The advantages to using numeric, auto incremented primary keys are numerous, but the most impactful benefits are faster speed when performing queries and data-independence when searching through thousands of records which might contain frequently altered data elsewhere in the table. DROP TABLE and the CREATE TABLE statements to run those statements in separate batches. In that case you'd have a short-lived gap that then gets filled up. If you have a natural key that you want to use as the PK then you would probably want to put a unique constraint on the surrogate alternate key anyway. How to Define an Auto Increment Primary Key in SQL Server - First off, some test data to play with: CREATE TABLE dbo. You can't post or upload images. I started to use SQL Server recently and I still don't know the best way to do some things. I created all the tables with a column ID as the primary key. Table'; column does not allow nulls. The statement has been terminated. If your table is empty, you can drop and recreate the table again and add IDENTITY 1,1 to the column definition of id to make your id column in Project. Table id int IDENTITY 1,1 NOT NULL, col2 VARCHAR 50 NULL,... DROP TABLE and the CREATE TABLE statements to run those statements in separate batches. My preferred method for a non-empty table is to use the ALTER TABLE... SWITCH method which is a meta-data-only operation. This is a simple test-bed setup, consisting of the initial table, named dbo. SwitchTest1, and the target table containing an IDENTITY, named dbo. SwitchTest1' IS NOT NULL DROP TABLE dbo. SwitchTest2' IS NOT NULL DROP TABLE dbo. SwitchTest2; GO CREATE TABLE dbo. SwitchTest1 ID, SomeVal VALUES 1, 'This is a test' ; Here, we use the ALTER TABLE... SWITCH method to replace the data in dbo. SwitchTest2 table with data from dbo. SwitchTest1, while maintaining the definition of dbo. SwitchTest2 including the IDENTITY column. Although not strictly necessary, you probably want to rename any constraints included in the definition of dbo. SwitchTest2 after the fact to match what they used to be called in dbo. I've done that below for the primary key. BEGIN TRANSACTION BEGIN TRY ALTER TABLE dbo. SwitchTest1 SWITCH TO dbo. SwitchTest2; DROP TABLE dbo. SwitchTest1'; DBCC CHECKIDENT 'dbo. It does this by dropping the existing plan from the procedure cache forcing a new plan to be created the next time that the procedure or trigger is run. SwitchTest1 table has changed. Also, I'm running DBCC CHECKIDENT '' ; to cause the IDENTITY column to be updated with the next valid value to be used by an INSERT operation. Here, we're inserting a value into the SomeVal column without specifying a value for the ID column, which is now an IDENTITY column: INSERT INTO dbo. SwitchTest1; As you are on SQL Server 2012 you could also create a per table and apply it to the desired auto incrementing column with a default constraint that calls next value for. The two methods have some differences in behaviour which you may or may not find desirable. Is this not what you're looking for. Thom~ Excuse my typos and sometimes awful grammar. I guess if you want to make a column an identity column, you HAVE to use an ALTER TABLE command. Code should be in Standard SQL as much as possible and not local dialect. While IDENTITY can accept two arguments of the numeric seed where the values will begin from as well as the increment, these values are typically not specified with the IDENTITY constraint and instead are left as defaults both default to 1. SwitchTest1 SWITCH TO dbo. You can even query and re-set the counter. IDENTITY 1,1 syntax is only legitimate for an existing IDENTITY column for which you want to change the SEED and INCREMENT values.