DBMS_OUTPUT v11
The DBMS_OUTPUT
package provides the capability to send messages (lines of text) to a message buffer, or get messages from the message buffer. A message buffer is local to a single session. Use the DBMS_PIPE
package to send messages between sessions.
The procedures and functions available in the DBMS_OUTPUT
package are listed in the following table.
Function/Procedure | Return Type | Description |
---|---|---|
DISABLE | n/a | Disable the capability to send and receive messages. |
ENABLE(buffer_size) | n/a | Enable the capability to send and receive messages. |
GET_LINE(line OUT, status OUT) | n/a | Get a line from the message buffer. |
GET_LINES(lines OUT, numlines IN OUT) | n/a | Get multiple lines from the message buffer. |
NEW_LINE | n/a | Puts an end-of-line character sequence. |
PUT(item) | n/a | Puts a partial line without an end-of-line character sequence. |
PUT_LINE(item) | n/a | Puts a complete line with an end-of-line character sequence. |
SERVEROUTPUT(stdout) | n/a | Direct messages from PUT, PUT_LINE, or NEW_LINE to either standard output or the message buffer. |
The following table lists the public variables available in the DBMS_OUTPUT
package.
Public Variables | Data Type | Value | Description |
---|---|---|---|
chararr | TABLE | For message lines. |
CHARARR
The CHARARR
is for storing multiple message lines.
DISABLE
The DISABLE
procedure clears out the message buffer. Any messages in the buffer at the time the DISABLE
procedure is executed will no longer be accessible. Any messages subsequently sent with the PUT, PUT_LINE,
or NEW_LINE
procedures are discarded. No error is returned to the sender when the PUT, PUT_LINE,
or NEW_LINE
procedures are executed and messages have been disabled.
Use the ENABLE
procedure or SERVEROUTPUT(TRUE)
procedure to re-enable the sending and receiving of messages.
Examples
This anonymous block disables the sending and receiving messages in the current session.
ENABLE
The ENABLE
procedure enables the capability to send messages to the message buffer or retrieve messages from the message buffer. Running SERVEROUTPUT(TRUE)
also implicitly performs the ENABLE
procedure.
The destination of a message sent with PUT, PUT_LINE,
or NEW_LINE
depends upon the state of SERVEROUTPUT
.
- If the last state of
SERVEROUTPUT
isTRUE
, the message goes to standard output of the command line. - If the last state of
SERVEROUTPUT
isFALSE
, the message goes to the message buffer.
Parameter
buffer_size
Maximum length of the message buffer in bytes. If a buffer_size
of less than 2000 is specified, the buffer size is set to 2000.
Examples
The following anonymous block enables messages. Setting SERVEROUTPUT(TRUE)
forces them to standard output.
The same effect could have been achieved by simply using SERVEROUTPUT(TRUE)
.
The following anonymous block enables messages, but setting SERVEROUTPUT(FALSE)
directs messages to the message buffer.
GET_LINE
The GET_LINE
procedure provides the capability to retrieve a line of text from the message buffer. Only text that has been terminated by an end-of-line character sequence is retrieved – that is complete lines generated using PUT_LINE
, or by a series of PUT
calls followed by a NEW_LINE
call.
Parameters
line
Variable receiving the line of text from the message buffer.
status
0 if a line was returned from the message buffer, 1 if there was no line to return.
Examples
The following anonymous block writes the emp
table out to the message buffer as a comma-delimited string for each row.
The following anonymous block reads the message buffer and inserts the messages written by the prior example into a table named messages
. The rows in messages
are then displayed.
GET_LINES
The GET_LINES
procedure provides the capability to retrieve one or more lines of text from the message buffer into a collection. Only text that has been terminated by an end-of-line character sequence is retrieved – that is complete lines generated using PUT_LINE
, or by a series of PUT
calls followed by a NEW_LINE
call.
Parameters
lines
Table receiving the lines of text from the message buffer. See CHARARR
for a description of lines.
numlines IN
Number of lines to be retrieved from the message buffer.
numlines OUT
Actual number of lines retrieved from the message buffer. If the output value of numlines
is less than the input value, then there are no more lines left in the message buffer.
Examples
The following example uses the GET_LINES
procedure to store all rows from the emp
table that were placed on the message buffer, into an array.
NEW_LINE
The NEW_LINE
procedure writes an end-of-line character sequence in the message buffer.
Parameter
The NEW_LINE
procedure expects no parameters.
PUT
The PUT
procedure writes a string to the message buffer. No end-of-line character sequence is written at the end of the string. Use the NEW_LINE
procedure to add an end-of-line character sequence.
Parameter
item
Text written to the message buffer.
Examples
The following example uses the PUT
procedure to display a comma-delimited list of employees from the emp
table.
PUT_LINE
The PUT_LINE
procedure writes a single line to the message buffer including an end-of-line character sequence.
Parameter
item
Text to be written to the message buffer.
Examples
The following example uses the PUT_LINE
procedure to display a comma-delimited list of employees from the emp
table.
SERVEROUTPUT
The SERVEROUTPUT
procedure provides the capability to direct messages to standard output of the command line or to the message buffer. Setting SERVEROUTPUT(TRUE)
also performs an implicit execution of ENABLE
.
The default setting of SERVEROUTPUT
is implementation dependent. For example, in Oracle SQL*Plus, SERVEROUTPUT(FALSE)
is the default. In PSQL, SERVEROUTPUT(TRUE)
is the default. Also note that in Oracle SQL*Plus, this setting is controlled using the SQL*Plus SET
command, not by a stored procedure as implemented in Advanced Server.
Parameter
stdout
Set to TRUE
if subsequent PUT, PUT_LINE
, or NEW_LINE
commands are to send text directly to standard output of the command line. Set to FALSE
if text is to be sent to the message buffer.
Examples
The following anonymous block sends the first message to the command line and the second message to the message buffer.
If within the same session, the following anonymous block is executed, the message stored in the message buffer from the prior example is flushed and displayed on the command line as well as the new message.