Sep 18, 2008 · This is for SQL Server: ALTER TABLE TableName ADD ColumnName (type) -- NULL OR NOT NULL DEFAULT (default value) WITH VALUES Example: ALTER TABLE …

Nov 3, 2010 · It depends on what database you are using. In MySQL, you would use the "ALTER TABLE" syntax. I don't remember exactly how, but it would go something like this if you …

Mar 27, 2009 · ALTER TABLE table_name CHANGE COLUMN column_name column_name VARCHAR(200) NOT NULL DEFAULT ''; Change VARCHAR(200) to your datatype, and …

ALTER TABLE userlog ADD( user_id number ); create a sequence. CREATE SEQUENCE user_id_seq START WITH 1 INCREMENT BY 1 CACHE 20; Update the data in the table. …

@ChristopheHarris, sometimes it makes sense to have more than one column as the primary key. A one-to-many or many-to-many relationship table will likely have 2 or more foreign key …

Oct 22, 2009 · ALTER TABLE tablename DROP COLUMN columnname; ALTER TABLE tablename ADD columnname columntype; Note: only do this if you don't have data in the …

Oct 13, 2014 · This is why there is no WHERE clause for ALTER. It sounds like you are looking to drop this column only if all of the values are NULL in the table. What you need is an IF …

Oct 6, 2008 · In MySQL, the syntax is ALTER TABLE ... CHANGE: ALTER TABLE <table_name> CHANGE <column_name> <new_column_name> <data_type> ... Note that you can't just …

Jan 15, 2012 · IF COLUMNPROPERTY(OBJECT_ID('dbo.Person'), 'ColumnName', 'ColumnId') IS NULL BEGIN ALTER TABLE Person ADD ColumnName VARCHAR(MAX) NOT NULL …

Jul 14, 2017 · ALTER TABLE dbo.YourTable ADD ID INT IDENTITY and then you can make it the primary key: ALTER TABLE dbo.YourTable ADD CONSTRAINT PK_YourTable PRIMARY …