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Java updating resultset

java updating resultset-55

has " number Of Rows " employees"); rs.before First(); while (next()) Result Set rs = stmt.execute Query("SELECT COUNT(*) FROM EMPLOYEES"); rs.next(); int count = Int(1); println("XYZ, Inc.has " count " employees"); Result Set rs2 = stmt.execute Query( "SELECT LAST_NAME, FIRST_NAME FROM EMPLOYEES"); while (rs2.next()) With the scrollable result set, the cursor was just repositioned to start iterating through the same result set to retrieve its data.

java updating resultset-14

Programmers can take advantage of these new data types if they use a JDBC 2.0 driver that supports SQL3 types. If a driver implements the cursor movement methods in the JDBC 2.0 core API, its result sets can be scrollable.For maximum portability with forward only result sets, values should be retrieved from left to right, and column values should be read only once.With scrollable result sets, however, there are no such restrictions.A row in a relational database table can be thought of as representing an instance of the entity that the table represents.For example, if there is a table of employees, each row will contain information about a particular employee.In the past, a column value in a relational database table (and consequently in a result set table) had to be atomic; that is, it could be only one indivisible value.

For instance, an array could not be a column value because an array may be made up of multiple elements.

With the advent of SQL3 data types, however, the permissible content of table columns has expanded dramatically.

It is now possible for an array or even a user-defined structured type to be a column value.

If a column name is used as the parameter to a will return the value of the first matching column name.

Thus, if there are multiple columns with the same name, one needs to use a column index to be sure that the correct column value is retrieved.

Either the column name or the column number can be used to designate the column from which to retrieve data.