Fixed: Numerics in CSV, regression after pgx 5.2

With upgrade to pgx 5.2, issues with numeric types were addressed. While JSON marshalling works well, numeric to string conversion is still an issue. Reintroduced old workaround to fix the issue for CSV exports for now.

handler/csv_download/csv_download.go

@@ -23,6 +23,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/gofrs/uuid"
+	"github.com/jackc/pgx/v5/pgtype"
 )
 
 var (
@@ -201,12 +202,12 @@ func Handler(w http.ResponseWriter, r *http.Request) {
 
 			atr, exists := cache.AttributeIdMap[expr.AttributeId.Bytes]
 			if !exists {
-				handler.AbortRequest(w, handlerContext, errors.New("unknown attribute"), handler.ErrGeneral)
+				handler.AbortRequest(w, handlerContext, handler.ErrSchemaUnknownAttribute(expr.AttributeId.Bytes), handler.ErrGeneral)
 				return
 			}
 			rel, exists := cache.RelationIdMap[atr.RelationId]
 			if !exists {
-				handler.AbortRequest(w, handlerContext, errors.New("unknown relation"), handler.ErrGeneral)
+				handler.AbortRequest(w, handlerContext, handler.ErrSchemaUnknownRelation(atr.RelationId), handler.ErrGeneral)
 				return
 			}
 			columnNames[i] = rel.Name + "." + atr.Name
@@ -351,6 +352,8 @@ func dataToCsv(writer *csv.Writer, get types.DataGet, locUser *time.Location,
 				stringValues[pos] = parseIntegerValues(columnAttributeContentUse[pos], int64(v))
 			case int64:
 				stringValues[pos] = parseIntegerValues(columnAttributeContentUse[pos], v)
+			case pgtype.Numeric:
+				stringValues[pos] = tools.PgxNumericToString(v)
 			default:
 				stringValues[pos] = fmt.Sprintf("%v", value)
 			}

tools/tools.go

@@ -2,6 +2,7 @@ package tools
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"math/rand"
 	"os"
@@ -167,6 +168,36 @@ func UuidStringToNullUuid(input string) pgtype.UUID {
 	}
 }
 
+func PgxNumericToString(value pgtype.Numeric) string {
+	s := value.Int.String()
+	l := len(s)
+	e := int(value.Exp)
+
+	// zero exponent, as in 12 (int=12, len=2, exp=0)
+	if e == 0 {
+		return s
+	}
+
+	// positive exponent, as in 2500 (int=25, len=2, exp=2)
+	if e > 0 {
+		return fmt.Sprintf("%s%s", s, strings.Repeat("0", e))
+	}
+
+	// negative exponents
+	// equals out length, as in 0.12 (int=12, len=2, exp=-2)
+	if l+e == 0 {
+		return fmt.Sprintf("0.%s", s)
+	}
+
+	// below zero, as in 0.012 (int=12, len=2, exp=-3)
+	if l+e < 0 {
+		return fmt.Sprintf("0.%s%s", strings.Repeat("0", (l+e)-((l+e)*2)), s)
+	}
+
+	// above zero, as in 11.1 (int=111, len=3, exp=-1)
+	return fmt.Sprintf("%s.%s", s[0:l+e], s[l+e:])
+}
+
 func RandStringRunes(n int) string {
 	var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")