How to use OR condition in Slick database queries

Data and Databases
1

I’m working with Slick for database operations and need help with creating OR conditions in my queries. I want to fetch records that match either of two conditions.

Here’s what I’m trying to do:

val CustomerTable = TableQuery[Customer]
CustomerTable.filter(_.status === "active" || _.status.isEmpty)

I need this to generate SQL like:

select * from customer where status = 'active' or status is null

What’s the correct way to write OR conditions in Slick? I tried using || but it doesn’t seem to work as expected. Any help would be appreciated.

2

The issue arises from using ||, which is suited for boolean expressions rather than Slick’s query conditions. To implement OR logic, you should use a lambda expression for combining filters. The correct syntax is:

val CustomerTable = TableQuery[Customer]
CustomerTable.filter(c => c.status === "active" || c.status.isEmpty)

Alternatively, multiple filter calls could be used, as they are combined with AND, but for OR conditions, stick with the lambda method to ensure it works properly in the database context.

3

wait, are you getting specific error msgs with the || approach? also, is ur customer table’s status field actually set up as nullable in the schema? sometimes it’s not the query syntax - it’s how the column was defined originally.