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ClickHouse / clickhouse-jdbc-bridge

A JDBC proxy from ClickHouse to external databases
Apache License 2.0
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toDateTime64 accepts UInt32 with seconds, but jdbc-bridge offers UInt64 with millSeconds #162

Open Raffaellorr opened 2 years ago

Raffaellorr commented 2 years ago

When I transfrom Oracle's timestamp type, the result is error. The root cause is that ClickHouse toDateTime64() function requires UInt32 type with seconds, but jdbc-bridge offers UInt64 with millSeconds.

Example Oracle

CREATE TABLE system.t1 ( a timestamp );
INSERT INTO system.t1 values(to_timestamp('2022-11-03 19:36:00', 'YYYY-MM-DD HH24:MI:SS'));
SELECT * FROM system.t1;
A
2022-11-03 19:36:00.000

ClickHouse

select * from jdbc('oracle', 'select * from system.t1');
A
2299-12-31 23:00:00
Raffaellorr commented 2 years ago

I debugged the source code, found that it's because the ColumnDefinition's scale filed is set to 0. But it should be 6.

I suggest that the source code should be:

ColumnDefinition.java:479

old recommendedPrecision = precision < 0 ? DEFAULT_DATETIME64_PRECISION : precision;

new recommendedPrecision = precision <= 0 ? DEFAULT_DATETIME64_PRECISION : precision;