Enable all prefixes for named parameters and allow for unused named parameters (#811)

* Allow unused named parameters

Try to bind all named parameters and ignore those not used.

* Allow "@" and "$" for named parameters

* Add tests for named parameters

Co-authored-by: Guido Berhoerster <guido+go-sqlite3@berhoerster.name>

sqlite3.go

@@ -802,20 +802,29 @@ func (c *SQLiteConn) exec(ctx context.Context, query string, args []namedValue)
 		}
 		var res driver.Result
 		if s.(*SQLiteStmt).s != nil {
+			stmtArgs := make([]namedValue, 0, len(args))
 			na := s.NumInput()
-			if len(args) < na {
+			if len(args) - start < na {
 				s.Close()
 				return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args))
 			}
-			for i := 0; i < na; i++ {
-				args[i].Ordinal -= start
+			// consume the number of arguments used in the current
+			// statement and append all named arguments not
+			// contained therein
+			stmtArgs = append(stmtArgs, args[start:start+na]...)
+			for i := range args {
+				if (i < start || i >= na) && args[i].Name != "" {
+					stmtArgs = append(stmtArgs, args[i])
 				}
-			res, err = s.(*SQLiteStmt).exec(ctx, args[:na])
+			}
+			for i := range stmtArgs {
+				stmtArgs[i].Ordinal = i + 1
+			}
+			res, err = s.(*SQLiteStmt).exec(ctx, stmtArgs)
 			if err != nil && err != driver.ErrSkip {
 				s.Close()
 				return nil, err
 			}
-			args = args[na:]
 			start += na
 		}
 		tail := s.(*SQLiteStmt).t
@@ -848,24 +857,33 @@ func (c *SQLiteConn) Query(query string, args []driver.Value) (driver.Rows, erro
 func (c *SQLiteConn) query(ctx context.Context, query string, args []namedValue) (driver.Rows, error) {
 	start := 0
 	for {
+		stmtArgs := make([]namedValue, 0, len(args))
 		s, err := c.prepare(ctx, query)
 		if err != nil {
 			return nil, err
 		}
 		s.(*SQLiteStmt).cls = true
 		na := s.NumInput()
-		if len(args) < na {
-			return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args))
+		if len(args) - start < na {
+			return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args) - start)
 		}
-		for i := 0; i < na; i++ {
-			args[i].Ordinal -= start
+		// consume the number of arguments used in the current
+		// statement and append all named arguments not contained
+		// therein
+		stmtArgs = append(stmtArgs, args[start:start+na]...)
+		for i := range args {
+			if (i < start || i >= na) && args[i].Name != "" {
+				stmtArgs = append(stmtArgs, args[i])
 			}
-		rows, err := s.(*SQLiteStmt).query(ctx, args[:na])
+		}
+		for i := range stmtArgs {
+			stmtArgs[i].Ordinal = i + 1
+		}
+		rows, err := s.(*SQLiteStmt).query(ctx, stmtArgs)
 		if err != nil && err != driver.ErrSkip {
 			s.Close()
 			return rows, err
 		}
-		args = args[na:]
 		start += na
 		tail := s.(*SQLiteStmt).t
 		if tail == "" {
@@ -1778,11 +1796,6 @@ func (s *SQLiteStmt) NumInput() int {
 	return int(C.sqlite3_bind_parameter_count(s.s))
 }
 
-type bindArg struct {
-	n int
-	v driver.Value
-}
-
 var placeHolder = []byte{0}
 
 func (s *SQLiteStmt) bind(args []namedValue) error {
@@ -1791,16 +1804,26 @@ func (s *SQLiteStmt) bind(args []namedValue) error {
 		return s.c.lastError()
 	}
 
+	bindIndices := make([][3]int, len(args))
+	prefixes := []string{":", "@", "$"}
 	for i, v := range args {
+		bindIndices[i][0] = args[i].Ordinal
 		if v.Name != "" {
-			cname := C.CString(":" + v.Name)
-			args[i].Ordinal = int(C.sqlite3_bind_parameter_index(s.s, cname))
+			for j := range prefixes {
+				cname := C.CString(prefixes[j] + v.Name)
+				bindIndices[i][j] = int(C.sqlite3_bind_parameter_index(s.s, cname))
 				C.free(unsafe.Pointer(cname))
 			}
+			args[i].Ordinal = bindIndices[i][0]
+		}
 	}
 
-	for _, arg := range args {
-		n := C.int(arg.Ordinal)
+	for i, arg := range args {
+		for j := range bindIndices[i] {
+			if bindIndices[i][j] == 0 {
+				continue
+			}
+			n := C.int(bindIndices[i][j])
 			switch v := arg.Value.(type) {
 			case nil:
 				rv = C.sqlite3_bind_null(s.s, n)
@@ -1839,6 +1862,7 @@ func (s *SQLiteStmt) bind(args []namedValue) error {
 				return s.c.lastError()
 			}
 		}
+	}
 	return nil
 }
 

sqlite3_test.go

@@ -1778,6 +1778,45 @@ func TestInsertNilByteSlice(t *testing.T) {
 	}
 }
 
+func TestNamedParam(t *testing.T) {
+	tempFilename := TempFilename(t)
+	defer os.Remove(tempFilename)
+	db, err := sql.Open("sqlite3", tempFilename)
+	if err != nil {
+		t.Fatal("Failed to open database:", err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec("drop table foo")
+	_, err = db.Exec("create table foo (id integer, name text, amount integer)")
+	if err != nil {
+		t.Fatal("Failed to create table:", err)
+	}
+
+	_, err = db.Exec("insert into foo(id, name, amount) values(:id, @name, $amount)",
+		sql.Named("bar", 42), sql.Named("baz", "quux"),
+		sql.Named("amount", 123), sql.Named("corge", "waldo"),
+		sql.Named("id", 2), sql.Named("name", "grault"))
+	if err != nil {
+		t.Fatal("Failed to insert record with named parameters:", err)
+	}
+
+	rows, err := db.Query("select id, name, amount from foo")
+	if err != nil {
+		t.Fatal("Failed to select records:", err)
+	}
+	defer rows.Close()
+
+	rows.Next()
+
+	var id, amount int
+	var name string
+	rows.Scan(&id, &name, &amount)
+	if id != 2 || name != "grault" || amount != 123 {
+		t.Errorf("Expected %d, %q, %d for fetched result, but got %d, %q, %d:", 2, "grault", 123, id, name, amount)
+	}
+}
+
 var customFunctionOnce sync.Once
 
 func BenchmarkCustomFunctions(b *testing.B) {