如何使用 JPQL、Spring 数据存储库和 Hibernate 为 TimescaleDB `time_bucket` 函数参数化 Postgresql 间隔
How to parameterise Postgresql Interval for TimescaleDB `time_bucket` function with JPQL, Spring Data Repositories and Hibernate
我在 PostgreSQL 13 上使用带有 TimescaleDB 扩展的 Spring Data JPA(下面是 Hibernate,JPA 2.1),并希望使用 time_bucket
函数。这需要 bucket_width
这是一个 INTERVAL
和 time
这是数据的 TIMESTAMP
列。
我想把它放在 Spring 数据存储库中,并想使用 JPQL @Query
将数据提取到代表返回时间的聚合计数、平均值等的投影中水桶。我不想使用本机查询,因为我想与其他一些表连接,并自动填充它们的实体。
我将time_bucket
函数注册到我正在扩展的PostgisPG95Dialect
,像这样:
public class CustomPostgresqlDialect extends PostgisPG95Dialect {
public CustomPostgresqlDialect() {
super();
this.registerFunction("time_bucket", new StandardSQLFunction("time_bucket", new OffsetDateTimeType()));
}
}
如果 bucket_width
是硬编码的,则一切正常。但我希望 bucket_width
成为查询方法的参数。
以下工作正常:
@Query("select sys as system, "
+ "function('time_bucket', '10 mins', vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', '10 mins', vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to);
但是当我尝试参数化间隔时,我无法让它工作。我尝试将间隔作为字符串传递,因为这就是它在硬编码版本中的编写方式:
@Query("select sys as system, "
+ "function('time_bucket', :grouping, vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', :grouping, vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to,
@Param("grouping") String grouping);
其中 grouping
传递的值类似于 10 mins
.
但是为此我得到了这个错误:
SQL Error: 0, SQLState: 42883
ERROR: function time_bucket(character varying, timestamp with time zone) does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 61
然后我尝试将其更改为 Duration
,因为 Hibernate translates Duration
to PostgreSQL Interval types
@Query("select sys as system, "
+ "function('time_bucket', :grouping, vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', :grouping, vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to,
@Param("grouping") Duration grouping);
但我仍然遇到同样的错误,这次它认为 Duration 是 bigint
而不是 Interval
。
SQL Error: 0, SQLState: 42883
ERROR: function time_bucket(bigint, timestamp with time zone) does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 61
有没有办法使用 JPQL 参数化 Interval
?
有一种方法,但是您必须为此目的注册一个自定义函数,因为您不能转换为任意 SQL 类型。
public class CastInterval implements SQLFunction {
@Override
public boolean hasArguments() {
return true;
}
@Override
public boolean hasParenthesesIfNoArguments() {
return true;
}
@Override
public Type getReturnType(Type firstArgumentType, Mapping mapping) throws QueryException {
return firstArgumentType;
}
@Override
public String render(Type firstArgumentType, List args, SessionFactoryImplementor factory) throws QueryException {
return "cast(" + args.get(0) + " as interval)";
}
}
您必须在方言中注册该函数。
因此,如果按指示扩展方言,则可以通过以下方式完成:
this.registerFunction("castInterval", new CastInterval());
然后你可以这样使用它:function('time_bucket', castInterval(:grouping), vt.ts)
我在 PostgreSQL 13 上使用带有 TimescaleDB 扩展的 Spring Data JPA(下面是 Hibernate,JPA 2.1),并希望使用 time_bucket
函数。这需要 bucket_width
这是一个 INTERVAL
和 time
这是数据的 TIMESTAMP
列。
我想把它放在 Spring 数据存储库中,并想使用 JPQL @Query
将数据提取到代表返回时间的聚合计数、平均值等的投影中水桶。我不想使用本机查询,因为我想与其他一些表连接,并自动填充它们的实体。
我将time_bucket
函数注册到我正在扩展的PostgisPG95Dialect
,像这样:
public class CustomPostgresqlDialect extends PostgisPG95Dialect {
public CustomPostgresqlDialect() {
super();
this.registerFunction("time_bucket", new StandardSQLFunction("time_bucket", new OffsetDateTimeType()));
}
}
如果 bucket_width
是硬编码的,则一切正常。但我希望 bucket_width
成为查询方法的参数。
以下工作正常:
@Query("select sys as system, "
+ "function('time_bucket', '10 mins', vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', '10 mins', vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to);
但是当我尝试参数化间隔时,我无法让它工作。我尝试将间隔作为字符串传递,因为这就是它在硬编码版本中的编写方式:
@Query("select sys as system, "
+ "function('time_bucket', :grouping, vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', :grouping, vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to,
@Param("grouping") String grouping);
其中 grouping
传递的值类似于 10 mins
.
但是为此我得到了这个错误:
SQL Error: 0, SQLState: 42883
ERROR: function time_bucket(character varying, timestamp with time zone) does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 61
然后我尝试将其更改为 Duration
,因为 Hibernate translates Duration
to PostgreSQL Interval types
@Query("select sys as system, "
+ "function('time_bucket', :grouping, vt.ts) as startTime, "
+ "count(vt) as total, avg(vt.speed) as avgSpeed "
+ "from Data vt "
+ "JOIN vt.system sys "
+ "where sys.sysId = :sysId and "
+ "function('time_bucket', :grouping, vt.ts) between :from and :to "
+ "group by system, startTime "
+ "order by startTime")
List<SummaryAggregate> getSummaryData(
@Param("sysId") String sysId,
@Param("from") OffsetDateTime from,
@Param("to") OffsetDateTime to,
@Param("grouping") Duration grouping);
但我仍然遇到同样的错误,这次它认为 Duration 是 bigint
而不是 Interval
。
SQL Error: 0, SQLState: 42883
ERROR: function time_bucket(bigint, timestamp with time zone) does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 61
有没有办法使用 JPQL 参数化 Interval
?
有一种方法,但是您必须为此目的注册一个自定义函数,因为您不能转换为任意 SQL 类型。
public class CastInterval implements SQLFunction {
@Override
public boolean hasArguments() {
return true;
}
@Override
public boolean hasParenthesesIfNoArguments() {
return true;
}
@Override
public Type getReturnType(Type firstArgumentType, Mapping mapping) throws QueryException {
return firstArgumentType;
}
@Override
public String render(Type firstArgumentType, List args, SessionFactoryImplementor factory) throws QueryException {
return "cast(" + args.get(0) + " as interval)";
}
}
您必须在方言中注册该函数。
因此,如果按指示扩展方言,则可以通过以下方式完成:
this.registerFunction("castInterval", new CastInterval());
然后你可以这样使用它:function('time_bucket', castInterval(:grouping), vt.ts)