MYSQL触发器-插入之前更新其他表中的表中的值

Question

What I am trying is to update a value before insert from another table - here is what I've got:

2 Tables

hbrpg_geo{
...
id INT       //id that needs to be written into hbrpg_person
zip VARCHAR(10) //contains postcode
...
}

hbrpg_person{
...
 fk_postcode     // initially it's filled with UK postcode - but trigger should change value to id of hbrpg_geo of matching postcode (hbrpg_geo.zip). 
...
}

Trigger:

...

BEGIN
    DECLARE NP_VAR integer;
    DECLARE OP_VAR TEXT;
    SET OP_VAR = NEW.fk_postcode;
    SET TE_VAR = OP_VAR;
    SELECT hbrpg_geo.id INTO NP_VAR FROM hbrpg_geo WHERE hbrpg_geo.zip = OP_VAR;
    SET NEW.fk_postcode = NP_VAR;
END

It all appears to be working apart from:

SET OP_VAR = NEW.fk_postcode;

If I replace NEW.fk_postcode with a valid UK postcode in quotes (ie: "W1 3XX") it works fine and the trigger replaces the field fk_postcode with the id of hbrpg_geo table.

What I am doing wrong ? How can I assign the value of NEW.fk_postcode to the variable I just declared?

Answer 1

You have the sequence of assignments:

SET OP_VAR = NEW.fk_postcode;
. . .
SET NEW.fk_postcode = NP_VAR;

The column new.fk_postcode has the same type. But the columns are, respectively, text and integer .

You need to fix the type incompatibility. My guess is that fk_postcode is actually an integer and separate from the value (which would be a string).