Explain the following functions of Oracle with suitable examples:
(i) To_Char( ) (ii) Count( )
(iii) Trim( ) (iv) Length( )
Ans: (i) To_char( ): The TO_CHAR function converts a DATETIME, number, or NTEXT expression to a TEXT expression in a specified format. This function is typically used to format output data.
(ii) Count( ): The COUNT function returns the number of rows in a query.
The syntax for the COUNT function is:
SELECT COUNT (expression)
FROM tables
WHERE predicates;
(iii) Trim( ): In Oracle/PLSQL, the trim function removes all specified characters either from the beginning or the ending of a string.
The syntax for the trim function is:
trim( [ leading | trailing | both [ trim_character ] ] string1 )
leading - remove trim_string from the front of string1.
trailing - remove trim_string from the end of string1.
both - remove trim_string from the front and end of string1.
(iv) Length( ): In Oracle/PLSQL, the length function returns the length of the specified string.
The syntax for the length function is:
length(string1)
string1 is the string to return the length for. If string1 is NULL, then the function returns
NULL.