ResultSet
Introduction#
A ResultSet object maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result se
ResultSet
To create a ResultSet
you should to create a Statement
or PrepapredStatement
:
Create ResultSet with Statement
try {
Class.forName(driver);
Connection connection = DriverManager.getConnection(
"jdbc:somedb://localhost/databasename", "username", "password");
Statement statement = connection.createStatement();
ResultSet result = statement.executeQuery("SELECT * FROM my_table");
} catch (ClassNotFoundException | SQLException e) {
}
Create ResultSet with PrepapredStatement
try {
Class.forName(driver);
Connection connection = DriverManager.getConnection(
"jdbc:somedb://localhost/databasename", "username", "password");
PreparedStatement preparedStatement = connection.prepareStatement("SELECT * FROM my_table");
ResultSet result = preparedStatement.executeQuery();
} catch (ClassNotFoundException | SQLException e) {
}
Check if your ResultSet have information or not
if (result.next()) {
//yes result not empty
}
Get information from ResultSet
There are several type of information you can get from your ResultSet
like String, int, boolean, float, Blob
, … to get information you had to use a loop or a simple if :
if (result.next()) {
//get int from your result set
result.getInt("id");
//get string from your result set
result.getString("username");
//get boolean from your result set
result.getBoolean("validation");
//get double from your result set
result.getDouble("price");
}