选择查询日期的最大值

Question

I want to select max of date in hibernate but I get this error:

java.sql.SQLSyntaxErrorException: ORA-00932: inconsistent datatypes: expected TIMESTAMP got NUMBER

The query is :

select   coalesce(max (rc.dateTransactionReceipt),0  ) from MAMReceiptTransactions rc where   rc.mamItems.id =m.id ) as lastDateOfCharge

and the database is oracle. Type of this field in database is TIMESTAMP(6)

Answer 1

Trying to get 0 when timestamp doesn't make sense apart from being syntactically incorrect (The datatypes of the coalesce parameters must be compatible). Null itself sounds reasonable.

select max(rc.dateTransaction) from your_table rc

If you want to have a default timestamp returned, you can use that in the coalesce instead. Perhaps you want current timestamp returned in case the above returns null.

select coalesce(max(rc.dateTransaction), systimestamp) from your_table rc;