ResultSet exception - before start of result set

Question

I m having trouble getting data from a ResultSet object  Here is my code       String sql    SELECT type FROM node WHERE nid           PreparedStatement prep   conn prepareStatement sql       int meetNID   Integer parseInt node get BoutField field meet nid        prep setInt 1  meetNID        ResultSet result   prep executeQuery        result beforeFirst        String foundType   result getString 1        if    foundType equals  meet              throw new IllegalArgumentException String format  Node  d must be of type  meet   but was  s   meetNID  foundType            The error trace   Exception in thread  main  java sql SQLException  Before start of result set     at com mysql jdbc SQLError createSQLException SQLError java 1072      at com mysql jdbc SQLError createSQLException SQLError java 986      at com mysql jdbc SQLError createSQLException SQLError java 981      at com mysql jdbc SQLError createSQLException SQLError java 926      at com mysql jdbc ResultSetImpl checkRowPos ResultSetImpl java 841      at com mysql jdbc ResultSetImpl getStringInternal ResultSetImpl java 5656      at com mysql jdbc ResultSetImpl getString ResultSetImpl java 5576      at nth cumf3 nodeImport Validator validate Validator java 43      at nth cumf3 nodeImport Main main Main java 38    What am I doing wrong here

User · Answer

You have to call next   before you can start reading values from the first row  beforeFirst puts the cursor before the first row  so there s no data to read

User · Answer

You need to move the pointer to the first row  before asking for data   result beforeFirst    result next    String foundType   result getString 1

User · Answer

It s better if you create a class that has all the query methods  inclusively  in a different package  so instead of typing all the process in every class  you just call the method from that class

User · Answer

Every answer uses  next   or uses  beforeFirst   and then  next    But why not this   result first      So You just set the pointer to the first record and go from there  It s available since java 1 2 and I just wanted to mention this for anyone whose ResultSet exists of one specific record

User · Answer

You have to do a result next   before you can access the result   It s a very common idiom to do  ResultSet rs   stmt executeQuery    while  rs next         int foo   rs getInt 1

User · Answer

Basically you are positioning the cursor before the first row and then requesting data  You need to move the cursor to the first row    result next     String foundType   result getString 1     It is common to do this in an if statement or loop   if result next        foundType   result getString 1

[java] ResultSet exception - before start of result set

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