In Oracle PL/SQL, the CHARACTER data type is used to store fixed-length strings of characters. It is also sometimes referred to as CHAR.
When you define a CHAR variable or column, you need to specify the maximum length of the string it can hold. For example, if you define a CHAR(10) variable, it can hold a string of up to 10 characters.
One important thing to note about the CHARACTER data type in PL/SQL is that it pads any string that is shorter than the maximum length with spaces. For example, if you assign the value “hello” to a CHAR(10) variable, it will actually be stored as “hello ” (with six spaces added to the end).
Here is an example of how to define a CHAR variable in PL/SQL:
DECLARE my_char CHAR(10); BEGIN my_char := 'hello'; -- stored as 'hello ' dbms_output.put_line(my_char); END;
You can also use the CHARACTER data type in a table column definition. For example:
CREATE TABLE my_table ( id NUMBER, name CHAR(20), address CHAR(50) );
In this example, the name and address columns will always store strings of exactly 20 and 50 characters, respectively.
One thing to keep in mind when using the CHARACTER data type is that it can lead to inefficient use of storage space if you define columns with lengths that are longer than the actual data being stored. This can also affect performance, as the database has to allocate and manage more storage space than is necessary. It is therefore important to carefully consider the maximum length of any CHAR variables or columns you define.