Update Multiple Unique Rows in Single Query

I’d like to do the following, via knex, against a PostgreSQL DB:

update test as t set
    column_a = c.column_a
from (values
    ('123', 1),
    ('345', 2)  
) as c(column_b, column_a) 
where c.column_b = t.column_b;

My values will come from an array, of indeterminate size. Apart from string building the query (in a loop), and using knex.raw, is there anything knex can do to lend a hand?

[bendrucker]

You’re quite welcome! Just to clarify, you can basically stringify:

knex
  .into('test t')
  .update('column_a', 'c.column_a')
  .where('c.column_b', 't.column_b')
  .toString();

Then build your values statement, then insert it before where, then call the whole string with knex.raw. Gets trickier if you want to use bindings, but it’s doable.

[alexc101]

@58bits @bendrucker I’m trying to do something similar, but don’t understand how to build the values statement.

Here is what I have -

let string = knex
        .into('test t')
        .update('auth, c.auth')
        .from(knex.raw('values(1, 1, false), (2, 1, false)'))
        .where(knex.raw('c.id1 = t.id1 AND c.id2 = t.id2'))
        .toString()

        knex.raw(string)

Here is an sql fiddle of query I’m trying to recreate : http://sqlfiddle.com/#!17/62529/8

Hope you could help point me in the right direction?

Thanks