I am trying to use .UnionAll
method in go-pg library for golang.
var model []Customer
q0 := db.Model(&model).Where("name = ?", name0).Limit(4)
q1 := db.Model(&model).Where("name = ?", name1).Limit(3)
var result []Customer
if err := q0.UnionAll(q1).Limit(1).Select(&result); !as.NoError(err) {
return
}
This code produces the query:
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 1deificatory zonoid reprepare alacrify serenissime')
LIMIT 1)
UNION ALL
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 2fordless ferroboron radiability dandizette smutch'
LIMIT 3)
)
But I expect it to be:
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 1deificatory zonoid reprepare alacrify serenissime')
LIMIT 4)
UNION ALL
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 2fordless ferroboron radiability dandizette smutch')
LIMIT 3)
LIMIT 1
So how to use go-pg to get raw SQL query which I expect?
The thing is I can't apply the Limit 1
expression to the whole query for some reason.
Also, my Limit 4
is not applied correctly to the first union all
member.
My whole code is here.
I believe this query does the trick for you.
if err := db.Model().With("union_q", q0.UnionAll(q1)).Table("union_q").Limit(1).Select(&result); !as.NoError(err) {
return
}
The query isn't exactly what you wanted to be and as far as I know, the current version of go-pg can't generate that query. But this query does exactly what you wanted.