Initialize text, unitext, and image Columns

text, unitext, and image columns are not initialized until you update them or insert a non-null value. Initialization allocates at least one data page for each non-null text, unitext, or image data value. It also creates a pointer in the table to the location of the text, unitext, or image data.

For example, the following statements create the table testtext and initialize the blurb column by inserting a non-null value. The column now has a valid text pointer, and the first text page has been allocated.

create table texttest 
(title_id varchar(6), blurb text null, pub_id char(4)) 

insert texttest values 
("BU7832", "Straight Talk About Computers is an annotated analysis of what computers can do for you: a no-hype guide for the critical user.", "1389")

create table imagetest 
(image_id varchar(6), imagecol image null, graphic_id char(4)) 

insert imagetest values 
("94732", 0x0000008300000000000100000000013c, "1389")

For information on inserting and updating text, unitext, and image data with Client-Library programs, see the Client-Library/C Reference Manual.

• Define unitext Columns
  You can define a unitext column the same way you define other datatypes, using create table or alter table statements. You do not define the length of a unitext column, and the column can be null.