Files
go-common/app/service/main/account-recovery/dao/sqlbuilder/builder.go
2019-04-22 18:49:16 +08:00

106 lines
2.6 KiB
Go

// Copyright 2018 Huan Du. All rights reserved.
// Licensed under the MIT license that can be found in the LICENSE file.
package sqlbuilder
import (
"fmt"
)
// Builder is a general SQL builder.
// It's used by Args to create nested SQL like the `IN` expression in
// `SELECT * FROM t1 WHERE id IN (SELECT id FROM t2)`.
type Builder interface {
Build() (sql string, args []interface{})
BuildWithFlavor(flavor Flavor, initialArg ...interface{}) (sql string, args []interface{})
}
type compiledBuilder struct {
args *Args
format string
}
func (cb *compiledBuilder) Build() (sql string, args []interface{}) {
return cb.args.Compile(cb.format)
}
func (cb *compiledBuilder) BuildWithFlavor(flavor Flavor, initialArg ...interface{}) (sql string, args []interface{}) {
return cb.args.CompileWithFlavor(cb.format, flavor, initialArg...)
}
type flavoredBuilder struct {
builder Builder
flavor Flavor
}
func (fb *flavoredBuilder) Build() (sql string, args []interface{}) {
return fb.builder.BuildWithFlavor(fb.flavor)
}
func (fb *flavoredBuilder) BuildWithFlavor(flavor Flavor, initialArg ...interface{}) (sql string, args []interface{}) {
return fb.builder.BuildWithFlavor(flavor, initialArg...)
}
// WithFlavor creates a new Builder based on builder with a default flavor.
func WithFlavor(builder Builder, flavor Flavor) Builder {
return &flavoredBuilder{
builder: builder,
flavor: flavor,
}
}
// Buildf creates a Builder from a format string using `fmt.Sprintf`-like syntax.
// As all arguments will be converted to a string internally, e.g. "$0",
// only `%v` and `%s` are valid.
func Buildf(format string, arg ...interface{}) Builder {
args := &Args{
Flavor: DefaultFlavor,
}
vars := make([]interface{}, 0, len(arg))
for _, a := range arg {
vars = append(vars, args.Add(a))
}
return &compiledBuilder{
args: args,
format: fmt.Sprintf(Escape(format), vars...),
}
}
// Build creates a Builder from a format string.
// The format string uses special syntax to represent arguments.
// See doc in `Args#Compile` for syntax details.
func Build(format string, arg ...interface{}) Builder {
args := &Args{
Flavor: DefaultFlavor,
}
for _, a := range arg {
args.Add(a)
}
return &compiledBuilder{
args: args,
format: format,
}
}
// BuildNamed creates a Builder from a format string.
// The format string uses `${key}` to refer the value of named by key.
func BuildNamed(format string, named map[string]interface{}) Builder {
args := &Args{
Flavor: DefaultFlavor,
onlyNamed: true,
}
for n, v := range named {
args.Add(Named(n, v))
}
return &compiledBuilder{
args: args,
format: format,
}
}