在另一个表上插入值后，MySQL触发

Question

I have a table with a list of my cellphone contacts this is the structure of contacts table.

And the other one is smartteleco table.

The ContactId of smartteleco table is FOREIGN KEY to the ContactId of contacts .

I'm creating a trigger that if I INSERT a value into contacts table and the ContactNumber1 value starts with 0918,0919,0920,0921 it will be stored in the CellNumber field of smartteleco table.

These are the triggers I've already tried but there is a syntax error and the error is always inside the IF STATEMENT .

CREATE TRIGGER addSmart
    AFTER INSERT ON contacts
        FOR EACH ROW
        BEGIN
             IF(substring(ContactNumber1,1,4) IN (0918,0919,0920,0921) = 1)
                SET CellNumber = substring(ContactNumber1,1,11);
             END IF;
        END



CREATE TRIGGER addSmart
    AFTER INSERT ON contacts
        FOR EACH ROW
        BEGIN
             IF(substring(ContactNumber1,1,4) IN (0918,0919,0920,0921) = 1)
                INSERT INTO smartteleco (CellNumber) VALUES (ContactNumber1);
             END IF;
        END



CREATE TRIGGER addSmart
        AFTER INSERT ON contacts
            FOR EACH ROW
            BEGIN
                 IF(substring(ContactNumber1,1,4) IN (0918,0919,0920,0921) = 1)
                    INSERT INTO smartteleco (NEW.CellNumber) VALUES (NEW.ContactNumber1);
                 END IF;
            END


CREATE TRIGGER addSmart
    AFTER INSERT ON contacts
        FOR EACH ROW
        BEGIN
             IF(substring(ContactNumber1,1,4) IN (0918,0919,0920,0921) = 1)
                SET CellNumber = ContactNumber1;
             END IF;
        END



  CREATE TRIGGER addSmart
    AFTER INSERT ON contacts
        FOR EACH ROW
        BEGIN
             IF(substring(ContactNumber1,1,4) IN (0918,0919,0920,0921) = 1)
                SET NEW.CellNumber = NEW.ContactNumber1;
             END IF;
        END

Answer 1

A row trigger cannot directly access the columns of the table to which it is attached. It can access the values in the newly-inserted record by using the pseudorecord NEW . To make your triggers work, just replace the references to ContactNumber1 with references to NEW.ContactNumber1 .

You also need to use the correct syntax for your IF structures, which is

IF <contition> THEN  --< You need this keyword
  <statement>
END IF;

You might also need to cast ContactNumber1 as CHAR to use substring() on it.

So the correct trigger syntax should be

CREATE TRIGGER addSmart
  AFTER INSERT ON contacts
  FOR EACH ROW
BEGIN
  IF(substring(CAST(NEW.ContactNumber1 AS CHAR(11)), 1, 4) IN ('0918', '0919', '0920' ,'0921'))
  THEN
    INSERT INTO smartteleco (ContactId, CellNumber)
      VALUES (NEW.ContactId, NEW.ContactNumber1);
  END IF;
END

EDIT: Syntax corrected. I also discovered that you will need to change the column ContactNumber1 from INT(11) to CHAR(11) , which is actually the preferred data type since you will never be performing arithmetic on a phone number.

Answer 2

Try this:

    BEGIN
         IF SUBSTRING(NEW.ContactNumber1,1,4) IN ('0918','0919','0920','0921') THEN
             INSERT INTO smartteleco (CellNumber) VALUES (NEW.ContactNumber1);
         END IF;
    END