From 3b23aeabbe0a26b2677ba20a559aff95ba282a8d Mon Sep 17 00:00:00 2001
From: jdl <jdl@desktop>
Date: Mon, 18 Nov 2024 17:01:17 +0100
Subject: [PATCH] wip

---
 sqlgen/sqlite.go.tmpl | 74 ++++++++++++++++++++++++++++---------------
 sqliteutil/errors.go  |  2 +-
 2 files changed, 50 insertions(+), 26 deletions(-)

diff --git a/sqlgen/sqlite.go.tmpl b/sqlgen/sqlite.go.tmpl
index d7db01c..bffc078 100644
--- a/sqlgen/sqlite.go.tmpl
+++ b/sqlgen/sqlite.go.tmpl
@@ -5,6 +5,24 @@ import (
 	"iter"
 )
 
+var (
+	ErrConstraint = errors.New("constraint violation")
+	ErrNotFound = errors.New("not found")
+)
+
+func translateError(err error) error {
+	if err == nil {
+		return nil
+	}
+	if e, ok := err.(sqlite3.Error); ok && e.Code == 19 {
+		return ErrConstraint
+	}
+	if errors.Is(err, sql.ErrNoRows) {
+		return ErrNotFound
+	}
+	return err
+}
+
 type TX interface {
 	Exec(query string, args ...any) (sql.Result, error)
 	Query(query string, args ...any) (*sql.Rows, error)
@@ -36,7 +54,7 @@ func {{.Type}}_Insert(
   }
 
 	_, err = tx.Exec("{{.InsertQuery}}", {{.InsertArgs}})
-	return err
+	return translateError(err)
 }
 
 {{- end}} {{/* if not .NoInsert */}}
@@ -48,27 +66,29 @@ func {{.Type}}_Insert(
 func {{.Type}}_Update(
 	tx TX,
 	row *{{.Type}},
-) (found bool, err error) {
+) (err error) {
   {{.Type}}_Sanitize(row)
   if err = {{.Type}}_Validate(row); err != nil {
-    return false, err
+    return err
   }
 
 	result, err := tx.Exec("{{.UpdateQuery}}", {{.UpdateArgs}})
 	if err != nil {
-		return false, err
+		return translateError(err)
 	}
 
 	n, err := result.RowsAffected()
 	if err != nil {
 		panic(err)
 	}
-
-	if n > 1 {
+	switch n {
+	case 0:
+		return ErrNotFound
+	case 1:
+		return nil
+	default:
 		panic("multiple rows updated")
 	}
-
-	return n != 0, nil
 }
 {{- end}}
 
@@ -77,27 +97,29 @@ func {{.Type}}_Update(
 func {{.Type}}_UpdateFull(
 	tx TX,
 	row *{{.Type}},
-) (found bool, err error) {
+) (err error) {
   {{.Type}}_Sanitize(row)
   if err = {{.Type}}_Validate(row); err != nil {
-    return false, err
+    return err
   }
 
 	result, err := tx.Exec("{{.UpdateFullQuery}}", {{.UpdateFullArgs}})
 	if err != nil {
-		return false, err
+		return translateError(err)
 	}
 
 	n, err := result.RowsAffected()
 	if err != nil {
 		panic(err)
 	}
-
-	if n > 1 {
+	switch n {
+		case 0:
+		return ErrNotFound
+	case 1:
+		return nil
+	default:
 		panic("multiple rows updated")
 	}
-
-	return n != 0, nil
 }
 {{- end}}
 
@@ -109,22 +131,24 @@ func {{.Type}}_UpdateFull(
 func {{.Type}}_Delete(
 	tx TX,
 	{{.PKFunctionArgs -}}
-) (found bool, err error) {
+) (err error) {
 	result, err := tx.Exec("{{.DeleteQuery}}", {{.DeleteArgs}})
-		if err != nil {
-		return false, err
+	if err != nil {
+		return translateError(err)
 	}
 
 	n, err := result.RowsAffected()
 	if err != nil {
 		panic(err)
 	}
-
-	if n > 1 {
+	switch n {
+		case 0:
+		return ErrNotFound
+	case 1:
+		return nil
+	default:
 		panic("multiple rows deleted")
 	}
-
-	return n != 0, nil
 }
 
 {{- end}}
@@ -138,7 +162,7 @@ func {{.Type}}_Get(
 ) {
   row = &{{.Type}}{}
 	r := tx.QueryRow("{{.GetQuery}}", {{.DeleteArgs}})
-	err = r.Scan({{.ScanArgs}})
+	err = translateError(r.Scan({{.ScanArgs}}))
 	return
 }
 
@@ -153,7 +177,7 @@ func {{.Type}}_GetWhere(
 ) {
   row = &{{.Type}}{}
 	r := tx.QueryRow(query, args...)
-	err = r.Scan({{.ScanArgs}})
+	err = translateError(r.Scan({{.ScanArgs}}))
 	return
 }
 
@@ -177,7 +201,7 @@ func {{.Type}}_Iterate(
 		defer rows.Close()
 		for rows.Next() {
 			row := &{{.Type}}{}
-			err := rows.Scan({{.ScanArgs}})
+			err := translateError(rows.Scan({{.ScanArgs}}))
 			if !yield(row, err) {
 				return
 			}
diff --git a/sqliteutil/errors.go b/sqliteutil/errors.go
index b0db407..9bdf060 100644
--- a/sqliteutil/errors.go
+++ b/sqliteutil/errors.go
@@ -2,7 +2,7 @@ package sqliteutil
 
 import "github.com/mattn/go-sqlite3"
 
-func ErrIsDuplicate(err error) bool {
+func ErrIsConstraint(err error) bool {
 	e, ok := err.(sqlite3.Error)
 	return ok && e.Code == 19
 }