gorm/clause/expression.go

169 lines
3.3 KiB
Go

package clause
import (
"strings"
)
// Expression expression interface
type Expression interface {
Build(builder Builder)
}
// NegationExpressionBuilder negation expression builder
type NegationExpressionBuilder interface {
NegationBuild(builder Builder)
}
// Expr raw expression
type Expr struct {
SQL string
Vars []interface{}
}
// Build build raw expression
func (expr Expr) Build(builder Builder) {
sql := expr.SQL
for _, v := range expr.Vars {
sql = strings.Replace(sql, "?", builder.AddVar(v), 1)
}
builder.Write(sql)
}
// IN Whether a value is within a set of values
type IN struct {
Column interface{}
Values []interface{}
}
func (in IN) Build(builder Builder) {
builder.WriteQuoted(in.Column)
switch len(in.Values) {
case 0:
builder.Write(" IN (NULL)")
case 1:
builder.Write(" = ", builder.AddVar(in.Values...))
default:
builder.Write(" IN (", builder.AddVar(in.Values...), ")")
}
}
func (in IN) NegationBuild(builder Builder) {
switch len(in.Values) {
case 0:
case 1:
builder.Write(" <> ", builder.AddVar(in.Values...))
default:
builder.Write(" NOT IN (", builder.AddVar(in.Values...), ")")
}
}
// Eq equal to for where
type Eq struct {
Column interface{}
Value interface{}
}
func (eq Eq) Build(builder Builder) {
builder.WriteQuoted(eq.Column)
if eq.Value == nil {
builder.Write(" IS NULL")
} else {
builder.Write(" = ", builder.AddVar(eq.Value))
}
}
func (eq Eq) NegationBuild(builder Builder) {
Neq{eq.Column, eq.Value}.Build(builder)
}
// Neq not equal to for where
type Neq Eq
func (neq Neq) Build(builder Builder) {
builder.WriteQuoted(neq.Column)
if neq.Value == nil {
builder.Write(" IS NOT NULL")
} else {
builder.Write(" <> ", builder.AddVar(neq.Value))
}
}
func (neq Neq) NegationBuild(builder Builder) {
Eq{neq.Column, neq.Value}.Build(builder)
}
// Gt greater than for where
type Gt Eq
func (gt Gt) Build(builder Builder) {
builder.WriteQuoted(gt.Column)
builder.Write(" > ", builder.AddVar(gt.Value))
}
func (gt Gt) NegationBuild(builder Builder) {
Lte{gt.Column, gt.Value}.Build(builder)
}
// Gte greater than or equal to for where
type Gte Eq
func (gte Gte) Build(builder Builder) {
builder.WriteQuoted(gte.Column)
builder.Write(" >= ", builder.AddVar(gte.Value))
}
func (gte Gte) NegationBuild(builder Builder) {
Lt{gte.Column, gte.Value}.Build(builder)
}
// Lt less than for where
type Lt Eq
func (lt Lt) Build(builder Builder) {
builder.WriteQuoted(lt.Column)
builder.Write(" < ", builder.AddVar(lt.Value))
}
func (lt Lt) NegationBuild(builder Builder) {
Gte{lt.Column, lt.Value}.Build(builder)
}
// Lte less than or equal to for where
type Lte Eq
func (lte Lte) Build(builder Builder) {
builder.WriteQuoted(lte.Column)
builder.Write(" <= ", builder.AddVar(lte.Value))
}
func (lte Lte) NegationBuild(builder Builder) {
Gt{lte.Column, lte.Value}.Build(builder)
}
// Like whether string matches regular expression
type Like Eq
func (like Like) Build(builder Builder) {
builder.WriteQuoted(like.Column)
builder.Write(" LIKE ", builder.AddVar(like.Value))
}
func (like Like) NegationBuild(builder Builder) {
builder.WriteQuoted(like.Column)
builder.Write(" NOT LIKE ", builder.AddVar(like.Value))
}
// Map
type Map map[interface{}]interface{}
func (m Map) Build(builder Builder) {
// TODO
}
func (m Map) NegationBuild(builder Builder) {
// TODO
}