Alter Table
Modifies table and column attributes.
Synopsis
ALTER TABLE table [ * ] ADD [ COLUMN ] column type ALTER TABLE table [ * ] ALTER [ COLUMN ] column { SET DEFAULT defaultvalue | DROP DEFAULT } ALTER TABLE table [ * ] RENAME [ COLUMN ] column TO newcolumn ALTER TABLE table RENAME TO newtable ALTER TABLE table ADD CONSTRAINT newconstraint definition ALTER TABLE table OWNER TO newowner
Parameters
tableThe name of the (existing) table you intend to modify.
columnThe name of a new column, or existing column that you intend to modify.
typeThe data type of a new column being created. (This is used only during the creation of a new column.)
defaultvalueA new default value for the specified column.
newcolumnA new name for
column.newtableA new name for
table.newconstraint definitionThe name and definition of a new table constraint to be added to an existing table. See Chapter 7, for more details on how to define a table constraint.
newownerThe new owner of
table(when transferring ownership).
Results
ALTERThe message returned when a column or table modification is completed successfully.
ERRORThe message returned if the table or column modifications cannot be completed, along with an explanation of what failed, if possible.
Description
The ALTER TABLE command is used to modify the structure of tables
existing within a database in various ways. To rename a column or table, use the RENAME keyword. Renaming in this manner will not alter any of the data in either a column or a table. If you wish to ...