Oracle table cast collection updating type using table cast
I can, for example, use pseudorecords to validate business rules, determine whether a column value has changed, and more.
In the following trigger, I enforce a salary freeze; no one is allowed to get a raise during these tough economic times: Take the Challenge!
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records because they are similar in structure to a record defined on a table with %ROWTYPE but are restricted in their usage.
The following block uses a cursor FOR loop to fetch only the last name of each employee, deposit that name into a record, and then display the value of the last_name field of that record: Passing Records as Parameters You can define parameters based on record types, and you can therefore pass records as arguments to subprograms.
Let’s look at examples of the ways to populate a record.
Cursor FOR Loops and Implicitly Declared Records Suppose I want to write a program to display the last names of all employees.
The most common form of an INSERT statement is where column_list is the list of columns that will be populated on insert and expression_list is the list of expressions that will be assigned to their respective columns.
If I want to provide a value for each column in a table that has, say, 500 columns, writing and managing that code can become quite tedious.For updates, use SET ROW to update all the columns in a row from the record: DECLARE l_employee omag_employees%ROWTYPE; BEGIN l_employee.employee_id := 500; l_employee.last_name := ' Mondrian'; l_employee.salary := 2000; UPDATE omag_employees SET ROW = l_employee WHERE employee_id = 100; END; Remember: this UPDATE sets the value of every column in the table, including your primary key, so you should use the SET ROW syntax with great care. User-defined record types come in handy when you find yourself declaring “sets” of individual variables, such as .) With this approach, you do more than avoid writing repetitive statements. RECORD statement to create your own record type is when a field of your record needs to be a PL/SQL-specific type, such as BOOLEAN.