MSSQL Upsert statement

queries/query_builders.go

@@ -283,6 +283,49 @@ func BuildUpsertQueryPostgres(dia Dialect, tableName string, updateOnConflict bo
 	return buf.String()
 }
 
+// BuildUpsertQueryMSSQL builds a SQL statement string using the upsertData provided.
+func BuildUpsertQueryMSSQL(dia Dialect, tableName string, primary, update, insert []string, output []string) string {
+	insert = strmangle.IdentQuoteSlice(dia.LQ, dia.RQ, insert)
+
+	buf := strmangle.GetBuffer()
+	defer strmangle.PutBuffer(buf)
+
+	startIndex := 1
+
+	fmt.Fprintf(buf, "MERGE INTO %s as [t]\n", tableName)
+	fmt.Fprintf(buf, "USING (SELECT %s) as [s] ([%s])\n",
+		strmangle.Placeholders(dia.IndexPlaceholders, len(primary), startIndex, 1),
+		strings.Join(primary, string(dia.RQ)+","+string(dia.LQ)))
+	fmt.Fprint(buf, "ON (")
+	for i, v := range primary {
+		if i != 0 {
+			fmt.Fprint(buf, " AND ")
+		}
+		fmt.Fprintf(buf, "[s].[%s] = [t].[%s]", v, v)
+	}
+	fmt.Fprint(buf, ")\n")
+
+	startIndex = len(primary) + 1
+
+	fmt.Fprint(buf, "WHEN MATCHED THEN ")
+	fmt.Fprintf(buf, "UPDATE SET %s\n", strmangle.SetParamNames(string(dia.LQ), string(dia.RQ), startIndex, update))
+
+	startIndex = len(primary) + 1 + len(update)
+
+	fmt.Fprint(buf, "WHEN NOT MATCHED THEN ")
+	fmt.Fprintf(buf, "INSERT (%s) VALUES (%s)",
+		strings.Join(insert, ", "),
+		strmangle.Placeholders(dia.IndexPlaceholders, len(insert), startIndex, 1))
+
+	if len(output) > 0 {
+		fmt.Fprintf(buf, "\nOUTPUT INSERTED.[%s];", strings.Join(output, "],INSERTED.["))
+	} else {
+		fmt.Fprint(buf, ";")
+	}
+
+	return buf.String()
+}
+
 func writeModifiers(q *Query, buf *bytes.Buffer, args *[]interface{}) {
 	if len(q.groupBy) != 0 {
 		fmt.Fprintf(buf, " GROUP BY %s", strings.Join(q.groupBy, ", "))