Do not create backups for new databases

database.go

@@ -8,8 +8,9 @@ import (
 
 // Db holds a connection to a SQLite database.
 type Db struct {
-	Db   *sqlite.Conn
+	Db     *sqlite.Conn
-	lock sync.Mutex
+	source string
+	lock   sync.Mutex
 }
 
 // OpenDb opens a new connection to a SQLite database.
@@ -21,7 +22,7 @@ func OpenDb(databaseSource string) (*Db, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &Db{Db: conn}, nil
+	return &Db{Db: conn, source: databaseSource}, nil
 }
 
 // Close closes the database.

migrator.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io/fs"
 	"log"
+	"os"
 	"path"
 	"strconv"
 	"strings"
@@ -40,6 +41,20 @@ func (d *Db) MigrateDb(filesystem ReadDirFileFS, directory string) error {
 	}
 	log.Printf("Current version is %d, max migration version is %d", currentVersion, latestVersion)
 
+	// Create a backup if we're not on the latest version
+	if currentVersion != 0 && currentVersion != latestVersion && d.source != ":memory:" {
+		target := d.source + ".backup." + strconv.Itoa(currentVersion)
+		log.Printf("Creating backup of database to %s", target)
+		data, err := d.Db.Serialize("main")
+		if err != nil {
+			return fmt.Errorf("error serializing database: %v", err)
+		}
+		err = os.WriteFile(target, data, 0644)
+		if err != nil {
+			return fmt.Errorf("error writing backup: %v", err)
+		}
+	}
+
 	// If we are no up-to-date, bring the db up-to-date
 	for currentVersion != latestVersion {
 		targetVersion := currentVersion + 1
@@ -74,6 +89,9 @@ func performSingleMigration(d *Db, migrationScript []byte, targetVersion int) er
 
 	for _, statement := range statements {
 		statement = strings.TrimSpace(statement)
+		if statement == "" {
+			continue
+		}
 		err = tx.Query(statement).Exec()
 		if err != nil {
 			return fmt.Errorf("error performing migration: %v", err)

query.go

@@ -34,21 +34,37 @@ func (d *Db) query(query string) *Query {
 }
 
 func (q *Query) Bind(args ...any) *Query {
+	into := 0
+	return q.bindInto(&into, args...)
+}
+
+func (q *Query) bindInto(into *int, args ...any) *Query {
 	if q.err != nil || q.stmt == nil {
 		return q
 	}
 	for i, arg := range args {
+		*into++
 		if asString, ok := arg.(string); ok {
-			q.stmt.BindText(i+1, asString)
+			q.stmt.BindText(*into, asString)
 		} else if asInt, ok := arg.(int); ok {
-			q.stmt.BindInt64(i+1, int64(asInt))
+			q.stmt.BindInt64(*into, int64(asInt))
 		} else if asInt, ok := arg.(int64); ok {
-			q.stmt.BindInt64(i+1, asInt)
+			q.stmt.BindInt64(*into, asInt)
 		} else if asBool, ok := arg.(bool); ok {
-			q.stmt.BindBool(i+1, asBool)
+			q.stmt.BindBool(*into, asBool)
 		} else {
-			q.err = fmt.Errorf("unsupported column type %s at index %d", reflect.TypeOf(arg).Name(), i)
+			// Check if the argument is a slice or array of any type
-			return q
+			v := reflect.ValueOf(arg)
+			if v.Kind() == reflect.Slice || v.Kind() == reflect.Array {
+				*into--
+				for i := 0; i < v.Len(); i++ {
+					q.bindInto(into, v.Index(i).Interface())
+				}
+			} else {
+				*into--
+				q.err = fmt.Errorf("unsupported column type %s at index %d", reflect.TypeOf(arg).Name(), i)
+				return q
+			}
 		}
 	}
 	return q
@@ -58,7 +74,7 @@ func (q *Query) Exec() (rerr error) {
 	defer q.unlock()
 
 	if q.stmt != nil {
-		defer func() { rerr = q.stmt.Finalize() }()
+		defer func() { forwardError(q.stmt.Finalize(), &rerr) }()
 	}
 	if q.err != nil {
 		return q.err
@@ -84,7 +100,7 @@ func (q *Query) ScanSingle(results ...any) (rerr error) {
 	defer q.unlock()
 	// Scan rows
 	if q.stmt != nil {
-		defer func() { rerr = q.stmt.Finalize() }()
+		defer func() { forwardError(q.stmt.Finalize(), &rerr) }()
 	}
 	if q.err != nil {
 		return q.err
@@ -138,6 +154,9 @@ type Rows struct {
 }
 
 func (q *Query) ScanMulti() (*Rows, error) {
+	if q.err != nil {
+		return nil, q.err
+	}
 	return &Rows{
 		query: q,
 	}, nil
@@ -173,23 +192,47 @@ func (r *Rows) MustNext() bool {
 
 func (r *Rows) Scan(results ...any) error {
 	for i, arg := range results {
-		if asString, ok := arg.(*string); ok {
+		err := r.scanArgument(i, arg)
-			*asString = r.query.stmt.ColumnText(i)
+		if err != nil {
-		} else if asInt, ok := arg.(*int); ok {
+			return err
-			*asInt = r.query.stmt.ColumnInt(i)
-		} else if asBool, ok := arg.(*bool); ok {
-			*asBool = r.query.stmt.ColumnBool(i)
-		} else {
-			if reflect.TypeOf(arg).Kind() != reflect.Ptr {
-				return fmt.Errorf("unsupported column type %s at index %d (it should be a pointer)", reflect.TypeOf(arg).Name(), i)
-			}
-			name := reflect.Indirect(reflect.ValueOf(arg)).Type().Name()
-			return fmt.Errorf("unsupported column type *%s at index %d", name, i)
 		}
 	}
 	return nil
 }
 
+func (r *Rows) scanArgument(i int, arg any) error {
+	if asString, ok := arg.(*string); ok {
+		*asString = r.query.stmt.ColumnText(i)
+	} else if asInt, ok := arg.(*int); ok {
+		*asInt = r.query.stmt.ColumnInt(i)
+	} else if asBool, ok := arg.(*bool); ok {
+		*asBool = r.query.stmt.ColumnBool(i)
+	} else if reflect.TypeOf(arg).Kind() == reflect.Ptr && reflect.TypeOf(arg).Elem().Kind() == reflect.Ptr {
+		return r.handleNullableType(i, arg)
+	} else {
+		if reflect.TypeOf(arg).Kind() != reflect.Ptr {
+			return fmt.Errorf("unsupported column type %s at index %d (it should be a pointer)", reflect.TypeOf(arg).Name(), i)
+		}
+		name := reflect.Indirect(reflect.ValueOf(arg)).Type().Name()
+		return fmt.Errorf("unsupported column type *%s at index %d", name, i)
+	}
+	return nil
+}
+
+func (r *Rows) handleNullableType(i int, asPtr any) error {
+	if r.query.stmt.ColumnIsNull(i) {
+		reflect.ValueOf(asPtr).Elem().Set(reflect.Zero(reflect.TypeOf(asPtr).Elem()))
+	} else {
+		value := reflect.New(reflect.TypeOf(asPtr).Elem().Elem()).Interface()
+		err := r.scanArgument(i, value)
+		if err != nil {
+			return err
+		}
+		reflect.ValueOf(asPtr).Elem().Set(reflect.ValueOf(value))
+	}
+	return nil
+}
+
 func (r *Rows) MustScan(results ...any) {
 	err := r.Scan(results...)
 	if err != nil {

query_test.go

@@ -73,11 +73,89 @@ func TestUpdateQuery(t *testing.T) {
 		tx := db.MustBegin()
 		defer tx.MustRollback()
 		tx.Query("insert into mytable(key, value) values ('lorem', 'bar')").MustExec()
-		tx.Query("update mytable set value = 'ipsum' where key = 'lorem'").MustExec()
+		value := "ipsum"
+		key := "lorem"
+		tx.Query("update mytable set value = ? where key = ?").Bind(value, key).MustExec()
 		tx.MustCommit()
 	}()
 
 	var value string
-	db.Query("select value from mytable where value = 'ipsum'").MustScanSingle(&value)
+	db.Query("select value from mytable where key = 'lorem'").MustScanSingle(&value)
 	require.Equal(t, "ipsum", value)
 }
+
+func TestUpdateQueryWithWrongArguments(t *testing.T) {
+	db := openTestDb(t)
+	value := "ipsum"
+	err := db.Query("insert into mytable(key, value) values ('lorem', ?)").Bind(&value).Exec()
+	require.Error(t, err)
+}
+
+func TestQueryWithPointerStringArguments(t *testing.T) {
+	db := openTestDb(t)
+	var result *string
+	err := db.Query("select value from mytable where key = 'foo'").ScanSingle(&result)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Equal(t, "bar", *result)
+}
+
+func TestQueryWithPointerStringArgumentsCanSetToNull(t *testing.T) {
+	db := openTestDb(t)
+	db.Query("update mytable set value=NULL where key = 'foo'").MustExec()
+	myString := "some string"
+	var result *string
+	result = &myString
+	err := db.Query("select value from mytable where key = 'foo'").ScanSingle(&result)
+	require.NoError(t, err)
+	require.Nil(t, result)
+}
+
+func TestDeleteQuery(t *testing.T) {
+	db := openTestDb(t)
+	db.Query("delete from mytable where key = 'foo'").MustExec()
+
+	var count int
+	db.Query("select count(*) from mytable where key = 'foo'").MustScanSingle(&count)
+	require.Equal(t, 0, count, "expected row to be deleted")
+}
+
+func TestTransactionRollback(t *testing.T) {
+	db := openTestDb(t)
+	func() {
+		tx := db.MustBegin()
+		defer tx.MustRollback()
+		tx.Query("update mytable set value = 'ipsum' where key = 'foo'").MustExec()
+		// Intentionally not committing the transaction
+	}()
+
+	var value string
+	db.Query("select value from mytable where key = 'foo'").MustScanSingle(&value)
+	require.Equal(t, "bar", value, "expected original value after rollback")
+}
+
+func TestQueryWithInClause(t *testing.T) {
+	db := openTestDb(t)
+	// Insert additional test rows
+	db.Query("insert into mytable(key, value) values ('key1', 'value1')").MustExec()
+	db.Query("insert into mytable(key, value) values ('key2', 'value2')").MustExec()
+
+	// Execute query with IN clause
+	args := []string{"foo", "key2"}
+	rows, err := db.Query("select key, value from mytable where key in (?, ?)").Bind(args).ScanMulti()
+	require.NoError(t, err)
+	defer rows.MustFinish()
+
+	// Check results
+	results := make(map[string]string)
+	for rows.MustNext() {
+		var key, value string
+		rows.MustScan(&key, &value)
+		results[key] = value
+	}
+
+	// Verify we got exactly the expected results
+	require.Equal(t, 2, len(results), "expected 2 matching rows")
+	require.Equal(t, "bar", results["foo"], "unexpected value for key 'foo'")
+	require.Equal(t, "value2", results["key2"], "unexpected value for key 'key2'")
+}

util.go

@@ -0,0 +1,7 @@
+package mysqlite
+
+func forwardError(from error, to *error) {
+	if from != nil {
+		*to = from
+	}
+}