feat(storage): read only transactions for queries (#6415)

* fix: tests

* bastle wie en grosse

* fix(database): scan as callback

* fix tests

* fix merge failures

* remove as of system time

* refactor: remove unused test

* refacotr: remove unused lines

internal/query/prepare_test.go

@@ -15,6 +15,7 @@ import (
 	sq "github.com/Masterminds/squirrel"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/zitadel/zitadel/internal/database"
 )
 
 var (
@@ -53,14 +54,15 @@ func assertPrepare(t *testing.T, prepareFunc, expectedObject interface{}, sqlExp
 		}
 		return isErr(err)
 	}
-	object, ok := execScan(client, builder, scan, errCheck)
+	object, ok, didScan := execScan(&database.DB{DB: client}, builder, scan, errCheck)
 	if !ok {
 		t.Error(object)
 		return false
 	}
-
-	if !assert.Equal(t, expectedObject, object) {
-		return false
+	if didScan {
+		if !assert.Equal(t, expectedObject, object) {
+			return false
+		}
 	}
 
 	if err := mock.ExpectationsWereMet(); err != nil {
@@ -77,7 +79,23 @@ type sqlExpectation func(sqlmock.Sqlmock) sqlmock.Sqlmock
 
 func mockQuery(stmt string, cols []string, row []driver.Value, args ...driver.Value) func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
 	return func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+		m.ExpectBegin()
 		q := m.ExpectQuery(stmt).WithArgs(args...)
+		m.ExpectCommit()
+		result := sqlmock.NewRows(cols)
+		if len(row) > 0 {
+			result.AddRow(row...)
+		}
+		q.WillReturnRows(result)
+		return m
+	}
+}
+
+func mockQueryScanErr(stmt string, cols []string, row []driver.Value, args ...driver.Value) func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+	return func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+		m.ExpectBegin()
+		q := m.ExpectQuery(stmt).WithArgs(args...)
+		m.ExpectRollback()
 		result := sqlmock.NewRows(cols)
 		if len(row) > 0 {
 			result.AddRow(row...)
@@ -89,7 +107,28 @@ func mockQuery(stmt string, cols []string, row []driver.Value, args ...driver.Va
 
 func mockQueries(stmt string, cols []string, rows [][]driver.Value, args ...driver.Value) func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
 	return func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+		m.ExpectBegin()
 		q := m.ExpectQuery(stmt).WithArgs(args...)
+		m.ExpectCommit()
+		result := sqlmock.NewRows(cols)
+		count := uint64(len(rows))
+		for _, row := range rows {
+			if cols[len(cols)-1] == "count" {
+				row = append(row, count)
+			}
+			result.AddRow(row...)
+		}
+		q.WillReturnRows(result)
+		q.RowsWillBeClosed()
+		return m
+	}
+}
+
+func mockQueriesScanErr(stmt string, cols []string, rows [][]driver.Value, args ...driver.Value) func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+	return func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+		m.ExpectBegin()
+		q := m.ExpectQuery(stmt).WithArgs(args...)
+		m.ExpectRollback()
 		result := sqlmock.NewRows(cols)
 		count := uint64(len(rows))
 		for _, row := range rows {
@@ -106,8 +145,10 @@ func mockQueries(stmt string, cols []string, rows [][]driver.Value, args ...driv
 
 func mockQueryErr(stmt string, err error, args ...driver.Value) func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
 	return func(m sqlmock.Sqlmock) sqlmock.Sqlmock {
+		m.ExpectBegin()
 		q := m.ExpectQuery(stmt).WithArgs(args...)
 		q.WillReturnError(err)
+		m.ExpectRollback()
 		return m
 	}
 }
@@ -127,52 +168,65 @@ var (
 	selectBuilderType = reflect.TypeOf(sq.SelectBuilder{})
 )
 
-func execScan(client *sql.DB, builder sq.SelectBuilder, scan interface{}, errCheck checkErr) (interface{}, bool) {
+func execScan(client *database.DB, builder sq.SelectBuilder, scan interface{}, errCheck checkErr) (object interface{}, ok bool, didScan bool) {
 	scanType := reflect.TypeOf(scan)
 	err := validateScan(scanType)
 	if err != nil {
-		return err, false
+		return err, false, false
 	}
 
 	stmt, args, err := builder.ToSql()
 	if err != nil {
-		return fmt.Errorf("unexpeted error from sql builder: %w", err), false
+		return fmt.Errorf("unexpeted error from sql builder: %w", err), false, false
 	}
 
 	//resultSet represents *sql.Row or *sql.Rows,
 	// depending on whats assignable to the scan function
-	var resultSet interface{}
+	var res []reflect.Value
 
 	//execute sql stmt
 	// if scan(*sql.Rows)...
 	if scanType.In(0).AssignableTo(rowsType) {
-		resultSet, err = client.Query(stmt, args...)
-		if err != nil {
-			return errCheck(err)
-		}
+		err = client.Query(func(rows *sql.Rows) error {
+			didScan = true
+			res = reflect.ValueOf(scan).Call([]reflect.Value{reflect.ValueOf(rows)})
+			if err, ok := res[1].Interface().(error); ok {
+				return err
+			}
+			return nil
+		}, stmt, args...)
 
 		// if scan(*sql.Row)...
 	} else if scanType.In(0).AssignableTo(rowType) {
-		row := client.QueryRow(stmt, args...)
-		if row.Err() != nil {
-			return errCheck(row.Err())
-		}
-		resultSet = row
+		err = client.QueryRow(func(r *sql.Row) error {
+			didScan = true
+			res = reflect.ValueOf(scan).Call([]reflect.Value{reflect.ValueOf(r)})
+			if err, ok := res[1].Interface().(error); ok {
+				return err
+			}
+			return nil
+		}, stmt, args...)
+
 	} else {
-		return errors.New("scan: parameter must be *sql.Row or *sql.Rows"), false
+		return errors.New("scan: parameter must be *sql.Row or *sql.Rows"), false, false
 	}
 
-	// res contains object and error
-	res := reflect.ValueOf(scan).Call([]reflect.Value{reflect.ValueOf(resultSet)})
+	if err != nil {
+		err, ok := errCheck(err)
+		if didScan {
+			return res[0].Interface(), ok, didScan
+		}
+		return err, ok, didScan
+	}
 
 	//check for error
 	if res[1].Interface() != nil {
 		if err, ok := errCheck(res[1].Interface().(error)); !ok {
-			return fmt.Errorf("scan failed: %w", err), false
+			return fmt.Errorf("scan failed: %w", err), false, didScan
 		}
 	}
 
-	return res[0].Interface(), true
+	return res[0].Interface(), true, didScan
 }
 
 func validateScan(scanType reflect.Type) error {