MySQL Insert Where query

Question

What\'s wrong with this query:

INSERT INTO Users( weight, desiredWeight ) VALUES ( 160, 145 ) WHERE id = 1;

It works without the WHE

Answer 1

I am aware that this is a old post but I hope that this will still help somebody, with what I hope is a simple example:

background:

I had a many to many case: the same user is listed multiple times with multiple values and I wanted to Create a new record, hence UPDATE wouldn't make sense in my case and I needed to address a particular user just like I would do using a WHERE clause.

INSERT into MyTable(aUser,aCar)
value(User123,Mini)

By using this construct you actually target a specific user (user123,who has other records) so you don't really need a where clause, I reckon.

the output could be:

aUser   aCar
user123 mini
user123 HisOtherCarThatWasThereBefore

Answer 2

You can do conditional INSERT based on user input. This query will do insert only if input vars '$userWeight' and '$userDesiredWeight' are not blank

INSERT INTO Users(weight, desiredWeight )
select '$userWeight', '$userDesiredWeight'  
FROM (select 1 a ) dummy
WHERE '$userWeight' != '' AND '$userDesiredWeight'!='';

Answer 3

You can do that with the below code:

INSERT INTO table2 (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM table1
WHERE condition