forked from Shiloh/githaven
88 lines
1.6 KiB
Go
88 lines
1.6 KiB
Go
// Copyright 2016 The Xorm Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package builder
|
|
|
|
import (
|
|
"bytes"
|
|
"io"
|
|
)
|
|
|
|
// Writer defines the interface
|
|
type Writer interface {
|
|
io.Writer
|
|
Append(...interface{})
|
|
}
|
|
|
|
var _ Writer = NewWriter()
|
|
|
|
// BytesWriter implments Writer and save SQL in bytes.Buffer
|
|
type BytesWriter struct {
|
|
writer *bytes.Buffer
|
|
buffer []byte
|
|
args []interface{}
|
|
}
|
|
|
|
// NewWriter creates a new string writer
|
|
func NewWriter() *BytesWriter {
|
|
w := &BytesWriter{}
|
|
w.writer = bytes.NewBuffer(w.buffer)
|
|
return w
|
|
}
|
|
|
|
// Write writes data to Writer
|
|
func (s *BytesWriter) Write(buf []byte) (int, error) {
|
|
return s.writer.Write(buf)
|
|
}
|
|
|
|
// Append appends args to Writer
|
|
func (s *BytesWriter) Append(args ...interface{}) {
|
|
s.args = append(s.args, args...)
|
|
}
|
|
|
|
// Cond defines an interface
|
|
type Cond interface {
|
|
WriteTo(Writer) error
|
|
And(...Cond) Cond
|
|
Or(...Cond) Cond
|
|
IsValid() bool
|
|
}
|
|
|
|
type condEmpty struct{}
|
|
|
|
var _ Cond = condEmpty{}
|
|
|
|
// NewCond creates an empty condition
|
|
func NewCond() Cond {
|
|
return condEmpty{}
|
|
}
|
|
|
|
func (condEmpty) WriteTo(w Writer) error {
|
|
return nil
|
|
}
|
|
|
|
func (condEmpty) And(conds ...Cond) Cond {
|
|
return And(conds...)
|
|
}
|
|
|
|
func (condEmpty) Or(conds ...Cond) Cond {
|
|
return Or(conds...)
|
|
}
|
|
|
|
func (condEmpty) IsValid() bool {
|
|
return false
|
|
}
|
|
|
|
func condToSQL(cond Cond) (string, []interface{}, error) {
|
|
if cond == nil || !cond.IsValid() {
|
|
return "", nil, nil
|
|
}
|
|
|
|
w := NewWriter()
|
|
if err := cond.WriteTo(w); err != nil {
|
|
return "", nil, err
|
|
}
|
|
return w.writer.String(), w.args, nil
|
|
}
|