How do I parametarize an operator? - postgresql

Question

I have the following sql statement:
SELECT pk, up FROM mytable WHERE 2 > 1 LIMIT 10
This is just for simplicity, obviously. I am able to parameterize any of the integers:
SELECT pk, up FROM mytable WHERE 2 > $1 LIMIT 10
BUT, when I try to parameterize the operator, eg:
SELECT pk, up FROM mytable WHERE 2 $1 1 LIMIT 10
I get:
pq: syntax error at or near "$1"
Full Code:
package main
import (
"database/sql"
_ "github.com/lib/pq"
"log"
)
func main() {
log.SetFlags(log.Lshortfile)
Db, err := sql.Open("postgres", "user=yoitsmeletmein password=supersecretyo host=what.a.host dbname=mydb sslmode=require")
if err != nil {
log.Fatal("Cannot connect to db: ", err)
}
q := `SELECT pk FROM mytable WHERE 2 $1 1 LIMIT 10`
params := []interface{}{">"}
rows, err := Db.Query(q, params...)
if err != nil {
log.Println(err)
} else {
defer rows.Close()
for rows.Next() {
var pk int64
if err := rows.Scan(&pk); err != nil {
log.Fatal(err)
}
log.Println(pk)
}
}
}

Answer 1

Prepared statements allow to parametrize values, nothing else. It wouldn't make sense to parametrize operators to begin with, a statement cannot be prepared without knowing involved operators. And it would be potentially dangerous, opening vectors for SQL injection.
To switch operators, you'll have to concatenate a new query string in your client or use dynamic SQL with a server-side procedural language, the default being plpgsql.