(17) PL/SQL DBMS output

Dbms_output is a built-in package that is able to display output display debug information and send messages from PL/SQL blocks, subroutines, packages and triggers.
Let's take a look at a small snippet that will display all the user tables in the database.

//Try to list all the table names in the database: ' Tables in the database: '   );   For T in (SELECT table_name from user_tables) LOOP dbms_output.put_line (t.table_name); END LOOP; END; /

dbms_output subroutine
dbms_output contains the following sub-programs:

S.N	Sub-Program and purpose
1	dbms_output. DISABLE;     Suppress information output
2	dbms_output. ENABLE (buffer_size in INTEGER DEFAULT 20000);    Enable message output. Buffer_size=null represents an infinite buffer size
3	dbms_output. Get_line (Line out VARCHAR2, status out INTEGER);    retrieves a single line of cached information
4	dbms_output. Get_lines (LINES out Chararr, numlines in Out INTEGER);    retrieves an array of rows from the buffer
5	dbms_output. New_line;    place end of line flag
6	dbms_output. PUT (item in VARCHAR2);    partial line placed in the buffer
7	dbms_output. Put_Line (item in VARCHAR2);     rows placed in the buffer

Ii. examples

DECLARE lines Dbms_output.chararr; Num_lines number; BEGIN--Enable the buffer withdefaultSize20000dbms_output.enable; Dbms_output.put_line ('Hello reader!'); Dbms_output.put_line ('Hope You have enjoyed the tutorials!'); Dbms_output.put_line ('Have a great time exploring pl/sql!'); Num_lines:=3;    Dbms_output.get_lines (lines, num_lines); For I in1..   Num_lines LOOP Dbms_output.put_line (lines (i)); END LOOP; END;///when the above code is executed at the SQL prompt, it produces the following results:Hello Reader!Hope You have enjoyed the tutorials!Have a great time exploring PL/sql!PL/sql procedure successfully completed.

(17) PL/SQL DBMS output