如何在Java中使用jdbc准备好的语句读取sqlite文本列？

Question

Here is my sqlite table

CREATE TABLE hello ( 
    id INTEGER PRIMARY KEY AUTOINCREMENT,  
    import_data text,  
    export_data text
);

Here is my java code

Connection sqliteConnection = DriverManager.getConnection(db);
PreparedStatement preparedStatement = sqliteConnection.prepareStatement("select * from hello where export_data = ?;");
preparedStatement.setString(1, "ABD19E3C63"); // hex string
  ResultSet resultSet = preparedStatement.executeQuery();
  resultSet.next();
  importData  = resultSet.getString("import_data");
  System.out.println(importData); // prints nothing although I checked in the sqlite database that it exists.

so importData prints nothing although I can see in the sqlite database that it exists. not sure why?

sqlite query

select hex(import_data) from hello where hex(export_data)="ABD19E3C63"; // This works

The above query works in sqlite although I declared both columns as text

Answer 1

你应该试试这个吗？

PreparedStatement preparedStatement = sqliteConnection.prepareStatement("select * from hello where hex(export_data) = ?;");

Answer 2

You should use looping statement like the following.

while (resultSet.next()) {
    String import_data= resultSet.getString("import_data");
     System.out.println("Import_data"+import_data);
}