Does pgx offer any support for 'where in' clauses? I found in another stackoverflow thread that one should use string concatenation to build the query manually. IMO this is a bit error prone though, as you have to take care of escaping/sql injection and the like on your own.
I also tried to figure it out on my own:
const updatePurgedRecordingsStmt = "update recordings set status = 'DELETED', deleted = now() where status <> 'DELETED' and id in ($1);"
func (r *Repository) DeleteRecordings() error {
pool, err := r.connPool()
if err != nil {
return errors.Wrap(err, "cannot establish connection")
}
pgRecIds := &pgtype.Int4Array{}
if err := pgRecIds.Set([]int32{int32(1), int32(2)}); err != nil {
return errors.Wrap(err, "id conversion failed")
}
if _, err = pool.Exec(updatePurgedRecordingsStmt, pgRecIds); err != nil {
return errors.Wrap(err, "update stmt failed")
}
return nil
}
When I execute this code, I get the following error though:
ERROR: incorrect binary data format in bind parameter 1 (SQLSTATE 22P03)
The versions I am using:
Postgres:
db=> SELECT version();
version
-----------------------------------------------------------------------------------------------------------
PostgreSQL 9.6.11 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16), 64-bit
(1 row)
PGX:
github.com/jackc/fake v0.0.0-20150926172116-812a484cc733 h1:vr3AYkKovP8uR8AvSGGUK1IDqRa5lAAvEkZG1LKaCRc=
github.com/jackc/fake v0.0.0-20150926172116-812a484cc733/go.mod h1:WrMFNQdiFJ80sQsxDoMokWK1W5TQtxBFNpzWTD84ibQ=
github.com/jackc/pgx v3.3.0+incompatible h1:Wa90/+qsITBAPkAZjiByeIGHFcj3Ztu+VzrrIpHjL90=
github.com/jackc/pgx v3.3.0+incompatible/go.mod h1:0ZGrqGqkRlliWnWB4zKnWtjbSWbGkVEFm4TeybAXq+I=
github.com/lib/pq v1.0.0 h1:X5PMW56eZitiTeO7tKzZxFCSpbFZJtkMMooicw2us9A=
github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
As you already know IN expects a list of scalar expressions, not an array, however pgtype.Int4Array represents an array, not a list of scalar expressions.
"IMO this is a bit error prone though, as you have to take care of escaping/sql injection and the like on your own. "
Not necessarily, you can loop over your array, construct a string of parameter references, concatenate that to the query and then execute it passing in the array with ....
var paramrefs string
ids := []interface{}{1,2,3,4}
for i, _ := range ids {
paramrefs += `$` + strconv.Itoa(i+1) + `,`
}
paramrefs = paramrefs[:len(paramrefs)-1] // remove last ","
query := `UPDATE ... WHERE id IN (` + paramrefs + `)`
pool.Exec(query, ids...)
Alternatively you can use ANY instead of IN.
ids := &pgtype.Int4Array{}
ids.Set([]int{1,2,3,4})
query := `UPDATE ... WHERE id = ANY ($1)`
pool.Exec(query, ids)
(here you may have to cast the param reference to the appropriate array type, I'm not sure, give it a try without cast, if not ok, try with cast)