InstantForum.NET v4.1.4Teradata Forumshttp://www.teradata.com/teradataforum/info@teradata.comWed, 03 Dec 2008 15:35:14 GMT20http://www.teradata.com/teradataforum/Topic11762-9-1.aspxNeed to correct myslef. 'Alter table' can dropped a non index field. And 'ALTER TABLE ABC ADD ID NOT NULL;' works fine....Mon, 09 Jun 2008 17:52:24 GMTywjcjjhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxI don't think you can modify the property of the columns unless you rebuild the table with the new column type. Correct me if I am wrong. So far as I know 'Alter table' can only add a new column but not drop, neither modify columns.Mon, 09 Jun 2008 16:02:13 GMTywjcjjhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxNo, I want to modify the existing column only. I will not create any new column. No no ADD COLUMN will be there.Mon, 09 Jun 2008 05:03:21 GMTChitwanhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxThe way i understand it now is, you need to add NOT NULL column in a table after its creation using ALTER TABLE command. For that you can use following:ALTER TABLE ABC ADD Column2 INTEGER NOT NULL;Regards,AdeelMon, 09 Jun 2008 04:57:18 GMTAdeel.Chaudhryhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxHi Adeel,I can not add column after table is created. rather I would say the table has been created by my application is very simple table and now I want to ALTER it with adding NOT NULL key to a column. You can understand it as that is the flow of handeling my table column. Please assist me on the same. - ChitwanMon, 09 Jun 2008 04:45:08 GMTChitwanhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxHello,You can use it as follows:ALTER TABLE ABC ADD ID NOT NULL;You can only do that in non-indexed columns. The DDL you provided will not allow you to add this constraint. Following is the example with changed DDL and added constraint:CREATE TABLE ABC2 (ID INTEGER, ID1 INTEGER, ID2 INTEGER);SHOW TABLE ABC2;ALTER TABLE ABC2 ADD ID1 NOT NULL;SHOW TABLE ABC2;HTH.Regards,AdeelMon, 09 Jun 2008 04:25:44 GMTAdeel.Chaudhryhttp://www.teradata.com/teradataforum/Topic11762-9-1.aspxHi Experts,There is one table creating by my application and I want to modify it with it's column. The difference will be only that that column will becomes NOT NULL. I am able write a constraint on my table for NOT NULL of the column but it does not apear as column level.. he help me out with the correct syntex.CREATE TABLE ABC (ID INTEGER);Attemp toALTER TABLE ABC MODIFY check (Customer_ID integer not null);The above syntext is in correct. Please write me with correct syntex.Thanks in advance,Chitwan HumadPune.Mon, 09 Jun 2008 03:40:59 GMTChitwan