| 24. 1. 10. Declaring variables |
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In PL/SQL, variables must be included in the declaration block before they can be used. |
There are a number of ways to declare a variable. |
The most common way is by using a direct declaration, as shown here: |
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declare
variable_name [constant] DATATYPE [DEFAULT value |DEFAULT NULL];
begin
...
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The keyword constant means that the variable's value can't be changed in the body of the program. |
If you declare a variable as a constant, you must assign a default value to it by using the optional DEFAULT value clause. |
The following shows an example of correct declarations of variables: |
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SQL> declare
2 v_sal NUMBER;
3 v_name VARCHAR2(10) DEFAULT 'KING';
4 v_start_dt DATE := SYSDATE; -- same as DEFAULT SYSDATE
5 begin
6 NULL;
7 end;
8 /
PL/SQL procedure successfully completed.
SQL>
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