gorm/clause/joins.go

48 lines
906 B
Go

package clause
type JoinType string
const (
CrossJoin JoinType = "CROSS"
InnerJoin = "INNER"
LeftJoin = "LEFT"
RightJoin = "RIGHT"
)
// Join join clause for from
type Join struct {
Type JoinType
Table Table
ON Where
Using []string
Expression Expression
}
func (join Join) Build(builder Builder) {
if join.Expression != nil {
join.Expression.Build(builder)
} else {
if join.Type != "" {
builder.WriteString(string(join.Type))
builder.WriteByte(' ')
}
builder.WriteString("JOIN ")
builder.WriteQuoted(join.Table)
if len(join.ON.Exprs) > 0 {
builder.WriteString(" ON ")
join.ON.Build(builder)
} else if len(join.Using) > 0 {
builder.WriteString(" USING (")
for idx, c := range join.Using {
if idx > 0 {
builder.WriteByte(',')
}
builder.WriteQuoted(c)
}
builder.WriteByte(')')
}
}
}