Inserting a Row in a Table from Select Query - sql

Question

I'm using two Stored Procedures and two Table in My Sql Server.
First Table Structure.
Second Table Structure.
When a Customer books a Order then the Data will be Inserted in Table 1.
I'm using a Select Query in another Page Which Selects the Details from the Second Table.
If a row with a billno from first table is not Present in Second Table I want to Insert into the Second Table with some Default Values in the Select Query. How can I do this
??

Answer 1

If you want to insert in the same query, you will have to create a stored procedure. There you'll query if row exists in second table, and, if not, insert a new entity in second table.
Your code should look something like this:
-- --------------------------------------------------------------------------------
-- Routine DDL
-- Note: comments before and after the routine body will not be stored by the server
-- --------------------------------------------------------------------------------
DELIMITER $$
CREATE DEFINER=`table`#`%` PROCEDURE `insertBill`(IN billNo int, val1 int, val2 int, val3 int)
BEGIN
DECLARE totalres INT DEFAULT 0;
select count(*) from SECOND_TABLE where Bill_Number = billNo INTO totalres;
IF totalres < 1 THEN
INSERT into SECOND_TABLE values(val1,val2,val3);
END IF;
END
Val1,val2 and val3 are the valuest to be inserted into second table.
Hope this helps.

Answer 2

What you do is to LEFT JOIN the two tables and then select only the ones where the second table had no row to join, meaning the bill number were missing.
In the example below, you can replace #default_inform_status and #default_response_status with your default values.
INSERT INTO second_table (Bill_Number, Rest_Inform_Status, Rest_Response_Status)
SELECT ft.Bill_Number, #default_inform_status, #default_response_status
FROM first_table ft
LEFT JOIN second_table st
ON st.Bill_Number = ft.Bill_number
WHERE st.Bill_Number IS NULL
If it is possible to have duplicates of the same Bill_Number in the first table, you should also add a DISTINCT after the SELECT. But considering the fact that it is a primary key, this is no issue for you.