Conversion Functions

Overview

This practice covers the following topics:
• Writing a query that displays the current date
• Creating queries that require the use of numeric, character, and date functions.

Implicit Data-Type Conversion

For assignments, the Oracle server can automatically convert the following:
For expression evaluation, the Oracle Server can automatically convert the following:

Explicit Data-Type Conversion


Using the TO_CHAR Function with Dates

The format model:
• Must be enclosed in single quotation marks and is case sensitive
• Can include any valid date format element
• Has an fm element to remove padded blanks or suppress leading zeros
• Is separated from the date value by a comma.

Elements of the Date Format Model

• Time elements format the time portion of the date.

• Add character strings by enclosing them in double quotation marks.
• Number suffixes spell out numbers.

Using the TO_CHAR Function with Dates


Using the TO_CHAR Function with Numbers

These are some of the format elements you can use with the TO_CHAR function to display a number value as a character:

Using the TO_NUMBER and TO_DATE Functions

• Convert a character string to a number format using the TO_NUMBER function:
• Convert a character string to a date format using the TO_DATE function:
• These functions have an fx modifier. This modifier specifies the exact matching for the character argument and date format model of a TO_DATE function.

RR Date Format
Example of RR Date Format