What is user defined function in Oracle?
Purpose. The User Defined Function masking format lets you define your own logic to mask column data. The return value of the user-defined function is used to replace the original values. The user-defined function is a PL/SQL function that can be invoked in a SELECT statement.
Table of Contents
What are types of functions in Oracle?
Numeric Functions.
Why should we use Dbms_utility Format_error_backtrace?
Description The DBMS_UTILITY. format_error_backtrace function, added in Oracle Database 10g Release 2, is a critical subprogram to call when logging exceptions. It returns a string that traces the error back to the line on which it was raised!
What are aggregate functions in Oracle?
Aggregate functions return a single result row based on groups of rows, rather than on single rows. Aggregate functions can appear in select lists and in ORDER BY and HAVING clauses.
What is Pragma UDF?
The UDF pragma tells the compiler that the PL/SQL unit is a user defined function that is used primarily in SQL statements, which might improve its performance.
What are user-defined functions in SQL?
A user-defined function (UDF) lets you create a function by using a SQL expression or JavaScript code. A UDF accepts columns of input, performs actions on the input, and returns the result of those actions as a value. You can define a UDFs as either persistent or temporary.
What are the four types of functions available in SQL?
Types of SQL functions
- SQL Count function.
- SQL Sum function.
- SQL Avg function.
- SQL Max function.
- SQL Min function.
What is the difference between procedure and function in Oracle?
A function returns a value and control to calling function or code. A procedure returns the control but not any value to calling function or code. A procedure has support for try-catch blocks. A select statement can have a function call.
What is a stack trace in SQL?
In computing, a stack trace (also called stack backtrace or stack traceback) is a report of the active stack frames at a certain point in time during the execution of a program.
What is Utl_file in Oracle with example?
UTL_FILE I/O capabilities are similar to standard operating system stream file I/O ( OPEN , GET , PUT , CLOSE ) capabilities, but with some limitations. For example, you call the FOPEN function to return a file handle, which you use in subsequent calls to GET_LINE or PUT to perform stream I/O to a file.
What are the 5 aggregate functions?
SQL Aggregate Functions
- COUNT FUNCTION. COUNT function is used to Count the number of rows in a database table.
- SUM Function. Sum function is used to calculate the sum of all selected columns.
- AVG function. The AVG function is used to calculate the average value of the numeric type.
- MAX Function.
- MIN Function.
What are the 6 aggregate functions of SQL?
Transact-SQL provides the following aggregate functions:
- APPROX_COUNT_DISTINCT.
- AVG.
- CHECKSUM_AGG.
- COUNT.
- COUNT_BIG.
- GROUPING.
- GROUPING_ID.
- MAX.
When we use Pragma autonomous transaction?
The AUTONOMOUS_TRANSACTION pragma changes the way a subprogram works within a transaction. A subprogram marked with this pragma can do SQL operations and commit or roll back those operations, without committing or rolling back the data in the main transaction.
What are all types of user-defined functions?
There are two main types of user-defined functions in SQL based on the data they return: Scalar functions: These types of functions return a single value, i.e float, int, varchar, datetime, etc. Table-Valued functions: These functions return tables.
What is user-defined function with example?
A function is a block of code that performs a specific task. C allows you to define functions according to your need. These functions are known as user-defined functions. For example: Suppose, you need to create a circle and color it depending upon the radius and color.
What is system defined function in SQL?
System Defined Function
The functions that are defined by the system are known as “system defined functions”. In other words, all the built-in functions supported by the SQL server are referred to as system defined functions. Usage of the built-in functions saves much development time while performing certain tasks.
What is trigger in SQL?
A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT, UPDATE, or DELETE statements on a table or view.
Can we use DML statement in function?
You can use DML inside a PL/SQL function. However, the function can only be called from PL/SQL, not from SQL.
Can we call stored procedure from function?
We cannot call store procedure within a function. However, we can call a function within a store procedure.
What is err stack?
Stack trace error is a generic term frequently associated with long error messages. The stack trace information identifies where in the program the error occurs and is helpful to programmers. For users, the long stack track information may not be very useful for troubleshooting web errors.
How do I view SQL Profiler errors?
Step by Step
- Login to SQL Management Studio.
- Go to Tools>SQL Profiler.
- Trace Properties will open.
- Go to Events Selection tab, select Show all events and Show all columns.
- Under Events column, expand Error and Warningsf, and find User Error Messages.
What is the use of UTL_FILE_DIR in Oracle?
UTL_FILE_DIR lets you specify one or more directories that Oracle should use for PL/SQL file I/O. If you are specifying multiple directories, you must repeat the UTL_FILE_DIR parameter for each directory on separate lines of the initialization parameter file.
Where is the UTL_FILE directory?
UTL_FILE is available for both client-side and server-side PL/SQL. Both the client (text I/O) and server implementations are subject to server-side file system permission checking. In the past, accessible directories for the UTL_FILE functions were specified in the initialization file using the UTL_FILE_DIR parameter.
How do you define null in SQL?
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value. Note: A NULL value is different from a zero value or a field that contains spaces.
What is primary key SQL?
The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values. A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).