Get ColumnName ([]string) from a statement

This is dangerous to use since it can only be called when the Statement is live,
which sounds reasonable, but gets messy around the Row and Rows helper.

Author: karlseguin

conn.go

@@ -185,7 +185,7 @@ func (c Conn) Prepare(sql []byte, args ...any) (*Stmt, error) {
 
 func (c Conn) RowB(sql []byte, args ...any) Row {
 	stmt, err := c.Prepare(sql, args...)
-	return Row{stmt: stmt, err: err}
+	return Row{Stmt: stmt, err: err}
 }
 
 func (c Conn) Row(sql string, args ...any) Row {
@@ -194,7 +194,7 @@ func (c Conn) Row(sql string, args ...any) Row {
 
 func (c Conn) RowsB(sql []byte, args ...any) Rows {
 	stmt, err := c.Prepare(sql, args...)
-	return Rows{stmt: stmt, err: err}
+	return Rows{Stmt: stmt, err: err}
 }
 
 func (c Conn) Rows(sql string, args ...any) Rows {

row.go

@@ -1,15 +1,15 @@
 package sqlite
 
 type Row struct {
-	stmt *Stmt
+	Stmt *Stmt
 	err  error
 }
 
 func (r Row) Scan(dst ...interface{}) error {
 	if err := r.err; err != nil {
 		return err
 	}
-	stmt := r.stmt
+	stmt := r.Stmt
 	defer stmt.Close()
 
 	hasRow, err := stmt.Step()

rows.go

@@ -1,12 +1,12 @@
 package sqlite
 
 type Rows struct {
-	stmt *Stmt
+	Stmt *Stmt
 	err  error
 }
 
 func (r *Rows) Next() bool {
-	stmt := r.stmt
+	stmt := r.Stmt
 	if r.err != nil {
 		return false
 	}
@@ -21,7 +21,7 @@ func (r *Rows) Next() bool {
 }
 
 func (r *Rows) Scan(dst ...interface{}) error {
-	stmt := r.stmt
+	stmt := r.Stmt
 	for i, v := range dst {
 		if err := stmt.scan(i, v); err != nil {
 			r.err = err
@@ -38,7 +38,7 @@ func (r Rows) Error() error {
 
 func (r Rows) Close() {
 	// will be nil if the query was never valid
-	if stmt := r.stmt; stmt != nil {
+	if stmt := r.Stmt; stmt != nil {
 		stmt.Close()
 	}
 }

sqlite3_test.go

@@ -93,6 +93,12 @@ func Test_Bool_True(t *testing.T) {
 
 	var b1, b2 bool
 	row := db.RowB([]byte("select cint, cintn from test where id = ?"), db.LastInsertRowID())
+
+	names := row.Stmt.ColumnNames()
+	assert.Equal(t, len(names), 2)
+	assert.Equal(t, names[0], "cint")
+	assert.Equal(t, names[1], "cintn")
+
 	row.Scan(&b1, &b2)
 	assert.Equal(t, b1, true)
 	assert.Equal(t, b2, true)

stmt.go

@@ -49,6 +49,16 @@ func (s *Stmt) Close() error {
 	return nil
 }
 
+func (s *Stmt) ColumnNames() []string {
+	stmt := s.stmt
+	count := s.columnCount
+	names := make([]string, count)
+	for i := 0; i < count; i++ {
+		names[i] = C.GoString(C.sqlite3_column_name(stmt, C.int(i)))
+	}
+	return names
+}
+
 func (s *Stmt) Exec(args ...interface{}) error {
 	if err := s.Bind(args...); err != nil {
 		s.Reset()