Cygnus On-Premises Database Core
This module executes cloud-supplied, parameterized query definitions against the
on-premises JDBC DataSource without creating delimiter strings or String[][]
result buffers.
Query format
The query catalog value retains the operation prefix during incremental migration:
select!C0L!select id, name from operation where operation_type = ? and operated_by = ?
Legacy val0, val1, ... placeholders are rejected by the modern executor. They
remain available through the existing DBFunctions.FetchRunQuery path until each
query is migrated.
Usage
List<Operation> rows = dbFunctions.query(
600,
new Object[] { operationType, operatedBy },
Operation.class);
For maximum throughput, use an explicit mapper:
List<Operation> rows = dbFunctions.query(
600,
parameters,
result -> new Operation(result.getLong("id"), result.getString("name")));
Large reports can use stream(...) so rows are consumed without retaining the
whole result in memory. PostgreSQL cursor fetching is enabled by running reads with
auto-commit disabled and the configured fetch size.
Dynamic multi-value parameters
Use a typed array parameter with PostgreSQL ANY when the number of values is
not known in advance. The cached query remains parameterized:
select ... where op.description = any(?)
dbExecutor.query(
queryId,
new Object[] { portfolioId, SqlArrayParameter.text(descriptions) },
Option.class);
Factories are available for text, integer, smallint, bigint, numeric, boolean,
UUID, date, timestamp and timestamp-with-time-zone arrays. Use
SqlArrayParameter.of(postgresType, values) for another PostgreSQL scalar or
enum type. An empty collection is valid and causes = ANY(empty_array) to
match no rows.