I'm looking to essentially make this sort of query in Knex, but I can't quite get it to work:
select distinct *
from
(
select *, 1 as rank from table1 where Word like 'mike'
union
select *, 2 as rank from table1 where Word like 'mike%'
union
select *, 3 as rank from table1 where Word like '%mike%'
) as X
order by WordOrder
I noticed a similar issue here and tried to follow their advice, but can't seem to spot my bug (or if this is even the proper way of doing this in the first place).
var q = DB.knex('Users').select("*", "1 as rank").where("User", "like", query).
union(function() {
this.select("*", "2 as rank").where("User", "like", query + "%")
}).
union(function() {
this.select("*", "3 as rank").where("User", "like", query + "%")
});
DB.knex("Users").distinct("*").from('(' + q.toString() + ') as X').
orderBy('rank').select().then(...)
If it's any help, that particular query generates the following error:
Error: ER_PARSE_ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '1`` order by `rank` asc' at line 1, sql: select distinct * from `select` as ``1`` order by `rank` asc, bindings:
Knex. js is a “batteries-included” query builder for PostgreSQL, MySQL, SQLite3, Oracle, Amazon Redshift, and many other database drivers. We simply install the Knex library and the appropriate driver to query the database. Primarily made for Node. js, Knex supports both Node-style callbacks and promises.
Sequelize is an ORM that includes some query builder stuff; Knex is just a query builder, not an ORM.
Knex returns an array for all queries, even if there is only one row returned. The name of the user can be accessed from user[0] .
The knex. schema is a getter function, which returns a stateful object containing the query. Therefore be sure to obtain a new instance of the knex. schema for every query.
Version 0.6 of knex allows you to use subqueries pretty much anywhere now. Pop this in the chrome console at http://knexjs.org and you should see it gives you what you're looking for
knex.distinct('*').from(function() {
this.union(function() {
this.select('*', '1 as rank').from('table1').where('Word', 'like', 'mike')
}).union(function() {
this.select('*', '2 as rank').from('table1').where('Word', 'like', 'mike%')
}).union(function() {
this.select('*', '3 as rank').from('table1').where('Word', 'like', '%mike%')
})
.as('X')
}).orderBy('WordOrder').toString()
Edit: This answer refers to older version of knex. See other answer.
When I do this, I use the knex.raw
functionality. You can put any raw SQL in there. Like this:
var selectRaw = "SUM( IF( "+ table.id +" = 1, "+ table.value +", 0.00 )) as customAlias";
query.column( knex.raw( selectRaw ) );
You might even be able to build the query with knex, and then just use the .toString()
method to fill knex.raw
. My example was not part of their API (those IF
s...).
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With