同一行SQL / php的两个INSERT INTO语句

Question

I have been trying so hard and I can't find a solution for this problem. I have two different INSERT statements:

INSERT INTO `logList`(`User_ID`) SELECT `User_ID` FROM `userList` WHERE keyname='somevalue';
INSERT INTO `logList`(`ttime`) VALUES (CURRENT_TIMESTAMP);

If I execute them, they will of course insert 2 different rows. How can I make a single INSERT that returns only one row? Thank you in advance.

Answer 1

I am going to assume that this is what you really want:

INSERT INTO logList (User_ID, ttime)
    SELECT User_ID, CURRENT_TIMESTAMP
    FROM userList
    WHERE keyname = 'somevalue';

I doubt you want two separate rows, one with the user and NULL for time and the other with NULL for user and a value of the time.

I should note that you can define the loglist so ttime is defaulted to the current timestamp on the insert. The use of such defaults is described in the documentation .

If you did that, then:

INSERT INTO logList (User_ID)
    SELECT User_ID
    FROM userList
    WHERE keyname = 'somevalue';

would always set ttime .

Answer 2

As you ask, you can do it in one single Insert:

INSERT INTO `logList`(`User_ID`, `ttime`)
    SELECT `User_ID`, CURRENT_TIMESTAMP
    FROM `userList`
    WHERE keyname='somevalue';

Answer 3

You have this command:

INSERT INTO `logList`(`User_ID`) SELECT `User_ID` FROM `userList` WHERE keyname='somevalue';
INSERT INTO `logList`(`ttime`) VALUES (CURRENT_TIMESTAMP);

Which will create two rows and you want to create a single row. You can do that using a single command:

insert into loglist(USER_ID, ttime)
select User_ID, now()
from userList
where keyname = 'somevalue';

However, even though this is a solution, it is not a very elegant one. You should alter loglist and modify ttime to have the default value of CURRENT_TIMESTAMP and then you can simplify your insert command like this:

insert into loglist(USER_ID)
select User_ID
from userList
where keyname = 'somevalue';

this should be the normal behavior, since your loglist table should probably have the timestamp of the insertion moment anyway.