CODEWITHSUNDEEP
javajdbcresultset
zhoudu
zhoudu

Reputation: 661

Is there a universal way to check NULL in ResultSet?

In Java, is there a universal way to check NULL in a ResultSet (java.sql.ResultSet)?

The ResultSet interface does not have a direct method to check NULL. The closest thing is the wasNull() method. So, I have come up with this idea:

ResultSet rs;    //the ResultSet object
Object theValue;
boolean isValueNull;

theValue = rs.getObject("MY_COLUMN");
isValueNull = rs.wasNull();

After executing the code, isValueNull should indicate whether the value is NULL.

But, there is a question: Does rs.getObject(...) work for all columns? By contrast, if you call rs.getBigDecimal(...) on a string column, an exception may occur. I guess that rs.getObject(...) works for all columns, but I am not sure.

Upvotes: 1

Views: 477

Answers (1)

Krzysztof Cichocki
Krzysztof Cichocki

Reputation: 6412

https://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html

The universal way to check if last value from resultSet was null is to check rs.wasNull();

Yes, wasNull indicates whether the value was NULL.

Yes, getObject works on all columns.

Upvotes: 1

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