如何从 "timestamp without time zone" 字段收集到没有时区的 Java 时间戳

Question

我的 Jooq 查询：

dslContext.select(
                timeInterval,
                ifnull(avg(field(FieldName.AVERAGE, Double.class))
                        .cast(Double.class), 0.0))
                .from(channelTimebucketQuery)
                .groupBy(timeInterval)
                .orderBy(timeInterval)
                .collect(Collectors.toMap(Record2::component1, Record2::component2));

returns 一个附有时区的时间戳和一个双精度

但是我的 Profiler 说它应该 return 没有时区的时间戳。

select pg_typeof(time_bucket) from (

    select "alias_67258973"."time_bucket", coalesce(cast(avg(average) as double precision), 0.0) from (select "public"."time_bucket_gapfill"("bucket_width" := cast("public"."create_interval"("seconds" := 43200) as "pg_catalog"."interval"), "ts" := cast("public"."testTable"."time" as timestamp), "start" := cast(null as timestamp), "finish" := cast(null as timestamp)) as "time_bucket", avg("public"."testTable"."average") as "average" from "testTable" where ("public"."testTable"."device" in ('702088'  ) and "public"."testTable"."time" >= timestamp '2020-02-10 13:57:28.2212375' and "public"."testTable"."time" <= timestamp '2020-02-24 13:57:28.2222399') group by time_bucket) as "alias_67258973" group by "alias_67258973"."time_bucket" order by "alias_67258973"."time_bucket"
        ) as x;

时区从何而来？我如何将时区设置为 + 0000

Answer 1

SQL 类型 TIMESTAMP WITHOUT TIME ZONE（或只是 TIMESTAMP）的默认 JDBC 类型是 java.sql.Timestamp。由于我们都感到遗憾的历史原因，java.sql.Timestamp 扩展了 java.util.Date，它通过关联您的 JVM 时区（即 TimeZone.getDefault()) 带有 unix 时间戳。

SQL TIMESTAMP WITHOUT TIME ZONE 数据类型的更好表示是 java.time.LocalDateTime，jOOQ 也支持它。较新版本的 jOOQ 代码生成器将设置 <javaTimeTypes>true</javaTimeTypes> 以使 JSR-310 类型成为默认类型。

尽管如此，尽管 java.sql.Timestamp 中调试器和相关的隐式时区造成混淆，但这两种数据类型是等价的，并且可以通过以下方式相互转换：

如何从 "timestamp without time zone" 字段收集到没有时区的 Java 时间戳

How to collect from a "timestamp without time zone" Field to a Java Timestamp without Timezone

java

jooq

timezone-offset

psql