Question

I am working on a java app that utilizes PreparedStatement.

SELECT FIELD1, FIELD2 FROM MYTABLE WHERE (FIELD1='firstFieldValue' OR FIELD1='' or 'firstFieldValue'='');

firstFieldValue is a parameter. And it is necessary to check that its value is empty in SQL.

I created a prepared statement with the following parametrized SQL:

SELECT FIELD1, FIELD2 FROM MYTABLE WHERE (FIELD1=? OR FIELD1='' or ?='');

and I set values as follows:

preparedStatementInstance.setString(1, this.firstFieldValue);
preparedStatementInstance.setString(2, this.firstFieldValue);

This way does not work. Execution fails.

I think the prepared statement SQL is wrong.

How can I fix the SQL for prepared statement for this case?

Answer 1

Just check it in java.

if firstFieldValue.equals("") 

then SELECT FIELD1, FIELD2 FROM MYTABLE 

else  

SELECT FIELD1, FIELD2 FROM MYTABLE WHERE (FIELD1=? OR FIELD1='');

preparedStatementInstance.setString(1, this.firstFieldValue);