ent · a8m · Jun 19, 2022 · Jun 19, 2022
diff --git a/dialect/sql/sqlgraph/errors.go b/dialect/sql/sqlgraph/errors.go
@@ -9,7 +9,7 @@ import (
 	"strings"
 )
 
-// IsConstraintError returns true if the error resulted from a DB constraint violation
+// IsConstraintError returns true if the error resulted from a database constraint violation.
 func IsConstraintError(err error) bool {
 	var e *ConstraintError
 	return errors.As(err, &e) || IsUniqueConstraintError(err) || IsForeignKeyConstraintError(err)
@@ -18,28 +18,27 @@ func IsConstraintError(err error) bool {
 // IsUniqueConstraintError reports if the error resulted from a DB uniqueness constraint violation.
 // e.g. duplicate value in unique index.
 func IsUniqueConstraintError(err error) bool {
-	uniquenessErrors := []string{
+	for _, s := range []string{
 		"Error 1062",                 // MySQL
 		"violates unique constraint", // Postgres
 		"UNIQUE constraint failed",   // SQLite
-	}
-	for _, s := range uniquenessErrors {
+	} {
 		if strings.Contains(err.Error(), s) {
 			return true
 		}
 	}
 	return false
 }
 
-// IsForeignKeyConstraintError reports if the error resulted from a DB FK constraint violation.
+// IsForeignKeyConstraintError reports if the error resulted from a database foreign-key constraint violation.
 // e.g. parent row does not exist.
 func IsForeignKeyConstraintError(err error) bool {
-	fkErrors := []string{
-		"Error 1452",                      // MySQL
+	for _, s := range []string{
+		"Error 1451",                      // MySQL (Cannot delete or update a parent row).
+		"Error 1452",                      // MySQL (Cannot add or update a child row).
 		"violates foreign key constraint", // Postgres
 		"FOREIGN KEY constraint failed",   // SQLite
-	}
-	for _, s := range fkErrors {
+	} {
 		if strings.Contains(err.Error(), s) {
 			return true
 		}

diff --git a/dialect/sql/sqlgraph/graph_test.go b/dialect/sql/sqlgraph/graph_test.go
@@ -2342,6 +2342,28 @@ func TestIsConstraintError(t *testing.T) {
 			expectedFK:         true,
 			expectedUnique:     false,
 		},
+		{
+			name: "MySQL FK",
+			errMessage: "Error 1451: Cannot delete or update a parent row: a foreign key constraint " +
+				"fails (`test`.`groups`, CONSTRAINT `groups_group_infos_info` FOREIGN KEY (`group_info`) REFERENCES `group_infos` (`id`))",
+			expectedConstraint: true,
+			expectedFK:         true,
+			expectedUnique:     false,
+		},
+		{
+			name:               "SQLite FK",
+			errMessage:         `FOREIGN KEY constraint failed`,
+			expectedConstraint: true,
+			expectedFK:         true,
+			expectedUnique:     false,
+		},
+		{
+			name:               "Postgres FK",
+			errMessage:         `pq: update or delete on table "group_infos" violates foreign key constraint "groups_group_infos_info" on table "groups"`,
+			expectedConstraint: true,
+			expectedFK:         true,
+			expectedUnique:     false,
+		},
 		{
 			name:               "MySQL Unique",
 			errMessage:         `insert node to table "file_types": UNIQUE constraint failed: file_types.name ent: constraint failed: insert node to table "file_types": UNIQUE constraint failed: file_types.name`,

diff --git a/entc/gen/template/dialect/sql/delete.tmpl b/entc/gen/template/dialect/sql/delete.tmpl
@@ -36,7 +36,11 @@ func ({{ $receiver}} *{{ $builder }}) sqlExec(ctx context.Context) (int, error)
 			}
 		}
 	}
-	return sqlgraph.DeleteNodes(ctx, {{ $receiver}}.driver, _spec)
+	affected, err := sqlgraph.DeleteNodes(ctx, {{ $receiver}}.driver, _spec)
+	if err != nil && sqlgraph.IsConstraintError(err) {
+		err = &ConstraintError{msg: err.Error(), wrap: err}
+	}
+	return affected, err
 }
 
 {{ end }}
diff --git a/entc/integration/cascadelete/ent/comment_delete.go b/entc/integration/cascadelete/ent/comment_delete.go
diff --git a/entc/integration/cascadelete/ent/post_delete.go b/entc/integration/cascadelete/ent/post_delete.go
diff --git a/entc/integration/cascadelete/ent/user_delete.go b/entc/integration/cascadelete/ent/user_delete.go
diff --git a/entc/integration/config/ent/user_delete.go b/entc/integration/config/ent/user_delete.go
diff --git a/entc/integration/customid/ent/account_delete.go b/entc/integration/customid/ent/account_delete.go
diff --git a/entc/integration/customid/ent/blob_delete.go b/entc/integration/customid/ent/blob_delete.go
diff --git a/entc/integration/customid/ent/car_delete.go b/entc/integration/customid/ent/car_delete.go
diff --git a/entc/integration/customid/ent/device_delete.go b/entc/integration/customid/ent/device_delete.go
diff --git a/entc/integration/customid/ent/doc_delete.go b/entc/integration/customid/ent/doc_delete.go
diff --git a/entc/integration/customid/ent/group_delete.go b/entc/integration/customid/ent/group_delete.go
diff --git a/entc/integration/customid/ent/mixinid_delete.go b/entc/integration/customid/ent/mixinid_delete.go
diff --git a/entc/integration/customid/ent/note_delete.go b/entc/integration/customid/ent/note_delete.go
diff --git a/entc/integration/customid/ent/other_delete.go b/entc/integration/customid/ent/other_delete.go
diff --git a/entc/integration/customid/ent/pet_delete.go b/entc/integration/customid/ent/pet_delete.go
diff --git a/entc/integration/customid/ent/revision_delete.go b/entc/integration/customid/ent/revision_delete.go
diff --git a/entc/integration/customid/ent/session_delete.go b/entc/integration/customid/ent/session_delete.go
diff --git a/entc/integration/customid/ent/token_delete.go b/entc/integration/customid/ent/token_delete.go
diff --git a/entc/integration/customid/ent/user_delete.go b/entc/integration/customid/ent/user_delete.go
diff --git a/entc/integration/edgefield/ent/car_delete.go b/entc/integration/edgefield/ent/car_delete.go
diff --git a/entc/integration/edgefield/ent/card_delete.go b/entc/integration/edgefield/ent/card_delete.go
diff --git a/entc/integration/edgefield/ent/info_delete.go b/entc/integration/edgefield/ent/info_delete.go
diff --git a/entc/integration/edgefield/ent/metadata_delete.go b/entc/integration/edgefield/ent/metadata_delete.go
diff --git a/entc/integration/edgefield/ent/node_delete.go b/entc/integration/edgefield/ent/node_delete.go
diff --git a/entc/integration/edgefield/ent/pet_delete.go b/entc/integration/edgefield/ent/pet_delete.go