qrz/vendor/xorm.io/builder/cond_exists.go

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2022-07-16 11:43:41 +02:00
// Copyright 2022 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 (
"errors"
"io"
)
type condExists struct {
subQuery *Builder
}
var _ Cond = condExists{}
// Exists returns Cond via condition
func Exists(subQuery *Builder) Cond {
return &condExists{
subQuery: subQuery,
}
}
func (condExists condExists) WriteTo(w Writer) error {
if !condExists.IsValid() {
return errors.New("exists condition is nov valid")
}
if _, err := io.WriteString(w, "EXISTS ("); err != nil {
return err
}
if err := condExists.subQuery.WriteTo(w); err != nil {
return err
}
_, err := io.WriteString(w, ")")
return err
}
func (condExists condExists) And(conds ...Cond) Cond {
return And(condExists, And(conds...))
}
func (condExists condExists) Or(conds ...Cond) Cond {
return Or(condExists, Or(conds...))
}
func (condExists condExists) IsValid() bool {
return condExists.subQuery != nil
}