Hey guys, I have a server for shopping mall. and I...

# server

[Poohrang]

Hey guys, I have a server for shopping mall. and I've created a database and some tables.
When user presses like button in client side, Ktor server will increase by one interestCnt with SQL update query.
But when I was trying to inrecase value of table, it doesn't work as below. (attached image1)

transaction {
    UsedItems.update({
        (UsedItems.e_mail eq receive.userEmail).and(UsedItems.id eq receive.usedItemId)}) {
        it[interestCnt] = interestCnt + 1 // occurs error
    }
}

interestCnt value had defined in UsedItems table as below (attached image2)

val interestCnt : Column<Int> = integer("interest_cnt").default(0)

When I tried to put just value(not increasing), It works properly (attached image3)

transaction {
    UsedItems.update({
        (UsedItems.e_mail eq receive.userEmail).and(UsedItems.id eq receive.usedItemId)}) {
        it[interestCnt] = 1
    }
}

I reffered the following code in exposed github documentation.
If you want to update column value with some expression like increment use update function or setter:

StarWarsFilms.update({ StarWarsFilms.sequelId eq 8 }) {
    with(SqlExpressionBuilder) {
       it.update(StarWarsFilms.sequelId, StarWarsFilms.sequelId + 1)
       // or 
       it[StarWarsFilms.sequelId] = StarWarsFilms.sequelId + 1
    }
}

My expectation is to be worked like sample code. but not

Is there any idea to solve this problem?
Thanks in advance.

[dave08]

// you mean this,no?
        it[interestCnt] = it[interestCnt] + 1

[dave08]

interestCnt itself is of type Column, so it cant be added to an Int

[Poohrang]

@dave08
I already tried above code
But i met the same result. 😞
I've uploaded attachment.

[Poohrang]

error.png

[dave08]

Do you have an interestCnt in some outer context, like your fun params?

[dave08]

If so, you would need it[this.interestCnt]

[dave08]

Or it[UsedItems.interestCnt]

[dave08]

Also maybe += is overrided to work for such a case?

[Poohrang]

it occurs still error even though above both guides are used.

[Poohrang]

I've just fixed it by adding following code.

with(SqlExpressionBuilder) {
  // Increment count
}

I missed it.
But I'm still curious about that why does it need to increase count?

Thanks for your support