update primary key in oracle

i 开发者_Python百科have table. which has 5 columns in that 3 of the columns makes primary key combinations.

table (cola, colb, colc, cold, cole)

i want to update one of the column which is in primary key group. how to do that?

its giving primary key constraint error.

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You should disable do your modification an re enable the constraints that are linked to your primary key. (Unique, non-null, etc...)

Take a look at this website

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If you really need to maintain uniqueness over these three columns, then define a unique constraint on the three columns making up your current PK, and then define a new surrogate primary key column.

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Just in case you have to change the referncing data too. First note contrary to MS-SQL-Server there is no foreign Key contraint with on update cascade see How to create a Foreign Key with “ON UPDATE CASCADE” on Oracle?.

Than I would insert a new row in the primary table, update the referencing table to reference the new row and finally delete the original primary row.