Oracle move column to the first position

Question

Is there any way to move an column in an Oracle table from last to first position? Someone has dropped the ID column, and recreated it. So now it is at the end, which is a problem because some of our PHP Scripts are using the first column as an identifier (one Abstract Model with more than 100 other Models using this base object...)

See also:

• In Oracle, is it possible to “insert” a column into a table?
• Inserting new columns in the middle of a table?

Answer 1

In Oracle 12c it is now easier to rearrange columns logically. It can be achived by making column invisible/visible.If you change a invisible column to visible , the column will appear last in the odering.

Consider Using Invisible Columns

Create wxyz table:

CREATE TABLE t ( w INT,
y VARCHAR2, z VARCHAR2, x VARCHAR2

);

rearrange the x column to the middle:

ALTER TABLE wxyz MODIFY (y INVISIBLE, z INVISIBLE); ALTER TABLE wxyz MODIFY (y VISIBLE, z VISIBLE);

DESCRIBE wxyz;

Name

w

x

y

z

Answer 2

the simplest way to modify the logical order of the columns of a table is to rename your table and create a view with the "right" column positions:

ALTER TABLE your_table RENAME TO your_table_t;

CREATE VIEW your_table AS SELECT <columns in the right order> FROM your_table_t;

-- grants on the view (the same as the table)
GRANT ** TO ** ON your_table;

Your application will behave as if the columns were in the "right" position. You don't have to touch at the physical structure.