Update record in table with array value - postgresql

Question

I am trying to update a record in a postgres table with an array (slice) of values. The table has the following DDL:
CREATE TABLE slm_files (
id uuid DEFAULT gen_random_uuid() PRIMARY KEY,
filename character varying NOT NULL,
status character varying NOT NULL,
original_headers text[]
);
and the Go code I have is as follows:
package main
import (
"context"
"database/sql"
"encoding/json"
"fmt"
"os"
"strings"
"time"
"github.com/aws/aws-lambda-go/events"
"github.com/aws/aws-lambda-go/lambda"
"github.com/lib/pq"
)
type message struct {
ID string `json:"id"`
Filename string `json:"filename"`
Status string `json:"status"`
OriginalHeaders []string `json:"OriginalHeaders"`
}
func main() {
host := os.Getenv("PGhost")
port := 5432
user := os.Getenv("PGuser")
password := os.Getenv("PGpassword")
dbname := os.Getenv("PGdbname")
pgConString := fmt.Sprintf("port=%d host=%s user=%s "+
"password=%s dbname=%s sslmode=disable",
port, host, user, password, dbname)
msgBody := `update_headers___
{
"id": "76b67119-d8c1-4a20-b53e-49e4972e2f19",
"filename": "SLM1171_inputData_preNCOA-5babc88b-1d14-468d-bf6e-c3b36ce90d95.csv",
"status": "Submitted",
"OriginalHeaders": [
"city",
"state",
"zipcode",
"full_name",
"individual_id"
]
}`
fmt.Println("Processing file", msgBody)
queryMethod := strings.Split(msgBody, "___")[0]
fieldDict := strings.Split(msgBody, "___")[1]
db, err := sql.Open("postgres", pgConString)
if err != nil {
panic(err)
}
fmt.Println("Connected Successfully")
defer db.Close()
body := message{}
json.Unmarshal([]byte(fieldDict), &body)
fmt.Println(queryMethod)
fmt.Println(body)
var sqlStatement string
switch queryMethod {
case "update_ncoa":
sqlStatement = fmt.Sprintf(`UPDATE slm_files SET status = '%s', updated_at = '%s' where id = '%s';`,
body.Status,
body.UpdatedAt,
body.ID,
)
case "update_headers":
sqlStatement = fmt.Sprintf(`UPDATE slm_files SET original_headers = '%s', updated_at = '%s' where id = '%s';`,
pq.Array(body.OriginalHeaders),
body.UpdatedAt,
body.ID,
)
}
fmt.Println(sqlStatement)
_, err = db.Query(sqlStatement)
if err != nil {
fmt.Println("Failed to run query", err)
return
}
}
fmt.Println("Query executed!")
return
}
but I keep getting the error
pq: malformed array literal: "&[first_name last_name city state zipcode full_name individual_id]": Error
null
I have read a few things on the internet that lead me to using pq.Array() but that doesnt seem to work.
I have read about the difference in format between Go arrays and Postgres arrays, so I had hoped that letting the pq.Array function would sort it out but apparently not.

Answer 1

As Peter advised, there's a lot to fix up with that database handling. And it's definitely worth redoing those SQL statements to not use Sprintf to make the query.
But in terms of just getting something working with postgres arrays and the pq library, you need to use the Value() method of pq.Array to get the postgres format. Change your update statement for the headers to something like this:
arrayVal, _ := pq.Array(body.OriginalHeaders).Value()
sqlStatement = fmt.Sprintf(`UPDATE slm_files SET original_headers = '%s', updated_at = '%s' where id = '%s';`,
arrayVal,
body.UpdatedAt,
body.ID,
)
And it's worth checking the return from the Value() method to make sure there are no errors, I just ignored it for the sake of a simple example.