Oracle PL/SQL Tutorial/PL SQL Data Types/Data Type Conversion

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Datatype Conversions: Implicit Conversion

   <source lang="sql">

SQL> SET SERVEROUTPUT ON SQL> SQL> DECLARE

 2    d1    DATE;
 3    cd1   VARCHAR2(10);
 4    cd2   VARCHAR2(10);
 5    n1    NUMBER;
 6    c_cn1   VARCHAR2(10);
 7    c_cn2   VARCHAR2(10);
 8  BEGIN
 9     cd1 := "15-Nov-99";
10     d1 := cd1;
11     cd2 := d1;
12     DBMS_OUTPUT.PUT_LINE("CD1 = " || cd1);
13     DBMS_OUTPUT.PUT_LINE("CD2 = " || cd2);
14     c_cn1 := "995";
15     n1 := c_cn1 + .99 ;
16     c_cn2 := n1;
17     DBMS_OUTPUT.PUT_LINE("c_cn1 = " || c_cn1);
18     DBMS_OUTPUT.PUT_LINE("c_cn2 = " || c_cn2);
19  END;
20  /

CD1 = 15-Nov-99 CD2 = 15-NOV-99 c_cn1 = 995 c_cn2 = 995.99 PL/SQL procedure successfully completed. SQL></source>


Explicit Conversion

Oracle has several built-in functions that are designed to convert information from one datatype to another.

Conversion functions.

Function Purpose TO_DATE Converts a character string to a date TO_NUMBER Converts a character string to a number TO_CHAR Converts either a number or a date to a character string