在预填充列上生成 null 违规的更新语句

Question

I'm trying to update rows in PostgreSQL DB. When I try to run an update query to update values in 2 columns (with no constraints). My table structure is as follows (variable names changed)

schema.table
|-> id (not null)
|-> company (varchar)
|-> model
|-> serial_number
|-> series

There is unique constraint on model and serial_number.

UPDATE schema.table 
SET company = 'Apple' WHERE model like 'iPhone%' AND series like 'X%';

The above snippet generates the following error even when the row already has a serial_number.

Reason:
SQL Error [23502]: ERROR: null value in column "serial_number" violates not-null constraint

I'd like to set company to "Apple" were model='iPhone' and series is like 'X%'.

Answer 1

This code:

UPDATE schema.table 
    SET company = 'Apple'
    WHERE model like 'iPhone%' AND series like 'X%';

Does not change the serial_number at all. Hence, I conclude that you have an update trigger on the table that is causing the problem. So, look into any triggers that are there.