Explicit Data Type Conversion in Oracle

In the world of database management, Oracle is a well-known name for its advanced features and capabilities. One of these features is explicit data type conversion, which can greatly enhance the efficiency and accuracy of data processing. In this blog, we will delve into the concept of explicit data type conversion in Oracle, how it works, and its benefits in optimizing database operations. We will also explore some practical examples to demonstrate the use of explicit data type conversion in real-world scenarios. The basic Conversion functions in Oracle are TO_CHAR, TO_NUMBER, TO_DATE

TO_CHAR

Purpose: Creates a VARCHAR2 character string from a numeric or date value using the format model fmt.

Number transformation: The following characters, which are returned by number format elements, are specified by the nlsparams parameter:

• Decimal character

• Group separator

• Local currency symbol

• International currency symbol

The default parameter settings for the session are used if nlsparams or any other argument is absent.

conversion of dates The language in which the names of the month, day, and abbreviations are returned is specified by the nlsparams option. This function uses the session's default date languages if this parameter is missing.

Structure: TO_CHAR(number|date,[ fmt],[nlsparams])

Example1: Select TO_CHAR('09-APR-23','DD-MM-RRRR') from dual;

Result: 09-04-2023

TO_NUMBER

Purpose: Creates a number from a character string of digits using the format model fmt, which is an optional parameter. The nlsparams parameter serves the same purpose for number conversion in this method as it does in the TO CHAR function.

Structure: TO_NUMBER(char,[fmt],[nlsparams])

Example1: Select TO_NUMBER('0100.50') from dual;

Result: 100.5

TO_DATE

Purpose: transforms a character string that represents a date into a date value using the provided fmt. The format is DD-MON-YY if fmt is omitted. Similar to the TO CHAR function for date conversion, this method also uses the nlsparams parameter.

Structure: TO_DATE(char,[fmt],[nlsparams])

Example1: Select TO_DATE('09-APR-23','DD-MM-RR') from dual;

Result: 09-04-23