PostgreSql数据库中nulls first/last用法

1、打开Navicat工具,执行如下语句,创秃赈沙嚣建测试表CREATE TABLE "public"."t_user_test" ( "name" varchar(255) COLLATE "pg_catalog"."default", "sort" int8);

2、执行如下语句,来插入测试数据INSERT INTO "public"."t_user_test"(&鳎溻趄酃quot;name", "sort") VALUES ('a', NULL);INSERT INTO "public"."t_user_test"("name", "sort") VALUES ('b', 2);INSERT INTO "public"."t_user_test"("name", "sort") VALUES ('c', 3);

3、使用如下查询语句,可以将null值的记录排在结果集的最前面select * from t_user_test order by sort desc nulls first;

4、使用如下查询语句,可以将null值的记录排在结果集的最后面select * from t_user_test order by sort desc nulls last;