Question

I have table for comunication between clients and operaters, which contains phone, id (1=client, 2=operater) date, message… and some other data.

I need to make stored procedure which will sort table like this

number1 operaters message
number1 clients message
number1 clients message
number1 operaters message
number1 *no message*
.
.
.

So, bassically, I need to find first message sent by operater and then client messages before next operaters message.
If after one operaters message there is no clients answer, I need to insert row like “no clients anwer” or something like that.

And that is large table, so will be good if it is less steps.

I know how to order by multiple columns, I know how to find first operaters message (select min time where id…) but I don’t know how to insert those rows where needed.

Thanks in advance for help.

And yeah, it’s MSSQL.

Answer 1

Didn’t actually test it, but this general idea should work:

INSERT INTO YOUR_TABLE(NUMBER, DATE, USER_ID, MESSAGE)
SELECT NUMBER, GETDATE(), 1, '*no message*'
FROM YOUR_TABLE T1
WHERE
    USER_ID = 2                       -- Operator.
    AND NOT EXISTS (
        SELECT *
        FROM YOUR_TABLE T2
        WHERE
            T1.NUMBER = T2.NUMBER
            AND T1.DATE <= T2.DATE
            AND USER_ID = 1           -- Client.
    )

In plain English: for each operator message that does not have a younger client message, insert a new client message.

(Based on your comment, USER_ID = 1 signifies a client and USER_ID = 2 operator.)

Also note that using GETDATE()assumes all other dates are correct (i.e. none of them are in the future), implying that newly inserted message must be younger than its “parent” operator message. If that cannot be assumed, you’ll probably need to use DATEADD on operator message’s DATE.