How to return custom error code in sqlite3?

问题

I have a trigger statement like this:

CREATE TRIGGER update_customer_address UPDATE OF address ON customers 
  BEGIN
    UPDATE orders SET address = new.address WHERE customer_name = old.name;
    -- RAISE ...
  END;
END;

EDIT:

I want to do a step:

int result = sqlite3_step(statement);

I know result returns the result code like SQLITE_DONE, SQLITE_ROW, and SQLITE_CONSTRAINT. I also discovered that RAISE ABORT within TRIGGER returns SQLITE_CONSTRAINT to result.

Is there a way for me to create a custom error code? I want to do something like

int result = sqlite3_step(statement);
// get custom error code here

Is it possible to raise with a custom error code in sqlite? Or are there any workarounds?

回答1:

You can throw an error using the RAISE() function. You have to use pre-defined error codes (IGNORE, ABORT, FAIL or ROLLBACK) but you can add a custom message:

CREATE TRIGGER update_customer_address UPDATE OF address ON customers 
BEGIN
  UPDATE orders SET address = new.address WHERE customer_name = old.name;
  SELECT CASE
    WHEN ( (SELECT * from orders WHERE address = 'old address!!') IS NOT NULL)
    THEN RAISE (FAIL, 'Can still find old address, not everything was updated!')
  END;
END;

Note that RAISE() is meant to be used only when something was wrong, see the doc for more information about raise() behavior.

回答2:

Yes ofcourse you can define custom error codes or messages. All messages sent by

raise(ERR, "message")

can be retreived in C/C++ through

const char *sqlite3_errmsg(sqlite3*);

来源：https://stackoverflow.com/questions/12701415/how-to-return-custom-error-code-in-sqlite3

标签

sql

sqlite