update

clauses/when_not_matched.go

@@ -0,0 +1,32 @@
+package clauses
+
+import (
+	"gorm.io/gorm/clause"
+)
+
+type WhenNotMatched struct {
+	clause.Values
+	Where clause.Where
+}
+
+func (w WhenNotMatched) Name() string {
+	return "WHEN NOT MATCHED"
+}
+
+func (w WhenNotMatched) Build(builder clause.Builder) {
+	if len(w.Columns) > 0 {
+		if len(w.Values.Values) != 1 {
+			panic("cannot insert more than one rows due to Oracle SQL language restriction")
+		}
+
+		builder.WriteString(" THEN")
+		builder.WriteString(" INSERT ")
+		w.Build(builder)
+
+		if len(w.Where.Exprs) > 0 {
+			builder.WriteString(w.Where.Name())
+			builder.WriteByte(' ')
+			w.Where.Build(builder)
+		}
+	}
+}