![]() There are known issues of long standing in PL/Java’s conversions to and from these types, detailed in issue #200. The conversions of non-zoned values involve a hidden dependency on the PostgreSQL session’s current setting of TimeZone, which can vary from session to session at the connecting client’s preference. For all of these conversions but one, PL/Java must do time zone computations, with the one exception being, unintuitively, timestamp with time zone. Those classes have never been a good representation for PostgreSQL date/time values, because they are based on, which implies knowledge of a time zone, even when they are used to represent PostgreSQL values with no time zone at all. ![]() The JDBC getObject and readObject methods that do not take a Class parameter will return objects of those types when retrieving PostgreSQL date or time values. PL/Java function parameters and returns can be declared in Java to have those types, objects of those types can be passed to tObject, ResultSet.updateObject, and SQLOutput.writeObject methods, as well as to the methods that are specific to those types. The first mappings to be specified in JDBC used the JDBC-specific classes, , and, all of which are based on (but only as an implementation detail they should always be treated as their own types and not as instances of ). Mapping between PostgreSQL and Java date/time types Legacy JDBC mappings It won't use the index unless you use the same function in the queryĬREATE INDEX ON. Ken> index it still doesn't seem to use the index for queries. Ken> Yeah, I thought I might have to do that, but when I create that > would be to do your own fixed-format date parsing function (and > If you absolutely can't change the column type, then one option Then substring($1 from '^\d\d\d\d-?\d\d-?\d\d')::dateĬREATE INDEX ON export_hch_encounter_history ( iso_date("Service_Date")) ĬREATE INDEX ON export_hch_encounter_history ( make_date(LEFT("Service_Date",4)::int,SUBSTRING("Service_Date",6,2)::int,SUBSTRING("Service_Date",9,2)::int)) EXPLAIN ANALYZE SELECT * FROM export_hch_encounter_history WHERE "Service_Date"::date BETWEEN ''::date AND ''::date QUERY PLAN If you absolutely can't change the column type, then one option would be If the column type were timestamp, though, then you could do comparisonsĭirectly, or cast the value to "date" (which is an immutable cast). (again, you might know that you're not using those, but the code With to_date or to_timestamp and a fixed format, because those functionsĪre also mutable since some of the format options are locale-dependent You can't make this a field of type "timestamp" rather than text?Ĭasts from text to either date or timestamp are mutable because theyĭepend on the current DateStyle value (_you_ might know that your valuesĪre always ISO format, but the code doesn't). I've got a text field in a table that holds this style of > Is there any way, hacky or otherwise, people know of to do this? Thanks > etc.), but all of them throw the error "functions in index expressionĬan you also show the actual index expression? > I've tried various ways of getting to a date (::date, LEFT(x,10)::date, > (as a date), because I have lots of queries that are searching for > I'd like to be able to create an index on the date portion of this field I've got a text field in a table that holds this style of timestamp:
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