refactor: 优化sql执行

Author: zhou-hao

hsweb-easy-orm-rdb/src/main/java/org/hswebframework/ezorm/rdb/executor/reactive/r2dbc/R2dbcReactiveSqlExecutor.java

@@ -81,7 +81,7 @@ protected <T> Flux<T> doExecute(Operation operation,
                                     SqlRequest request,
                                     Function<Result, Publisher<T>> mapper) {
         return Flux
-            .from(this.prepareStatement(connection.createStatement(request.getSql()), request).execute())
+            .defer(() -> this.prepareStatement(connection.createStatement(request.getSql()), request).execute())
             .flatMap(mapper)
             .doOnSubscribe(subscription -> printSql(logger, request))
             .doOnError(err -> logger.error("==>      Error: {}", request.toNativeSql(), err));