- JDBC's ResultSet methods:
click here
(too many to
discuss all of them !!!)
-
beforeFirst():
(use this method
to "rewind" the
result set !!!)
- Moves the read cursor
to the front of this
ResultSet object, just
before the
first row.
(Use this method if you want to re-read all the tuples in the ResultSet object all over again)
- Moves the read cursor
to the front of this
ResultSet object, just
before the
first row.
- first():
- Moves the read cursor to the first row of this ResultSet object
- absolute(rowNumber):
- Moves the read cursor
to the row rowNumber of this
ResultSet object
- Note:
rowNumber >= 1
If rowNumber = 1, it is the same as first().
- Moves the read cursor
to the row rowNumber of this
ResultSet object
- afterLast():
- Moves the read cursor
to the end of this
ResultSet object, just
after the
last row.
(Use this method to read the ResultSet data in the reverse order)
- Moves the read cursor
to the end of this
ResultSet object, just
after the
last row.
-
last():
- Moves the read cursor
to the last row of this
ResultSet object
(Use this method --- together with getRow( ) --- to find the number of rows in the ResultSet)
- Moves the read cursor
to the last row of this
ResultSet object
-
getRow():
- Return the row index of the
current row
(Use this method --- along with last() --- to find the number of rows in the ResultSet)
How to find the number of tuples in the ResultSet:
int NTuples; rset.last( ); // Move to the last tuple in result set "rset" NTuples = rset.getRow( ); // Get index of last tuple // = # tuples in result set "rset" // If you want to access the tuples now, // you will need to call: rset.beforeFirst( ) // to "rewind" the result set to the beginning..... - Return the row index of the
current row
-
beforeFirst():
(use this method
to "rewind" the
result set !!!)
- Example Program:
(Demo beforeFirst(),
last() and
getRow()
)
- Prog file: /home/cs377001/demo/JDBC/Employee2.java
How to run the program:
- Go to the directory: cd /home/cs377001/demo/JDBC
- To compile: javac -cp ".:/home/cs377001/lib/mysql-connector-java.jar" Employee2.java
- To run: java -cp ".:/home/cs377001/lib/mysql-connector-java.jar" Employee2