oracle命令和帮助

SQL> help;

HELP
----

Accesses this command line help system. Enter HELP INDEX or ? INDEX
for a list of topics. In iSQL*Plus, click the Help button to display
iSQL*Plus online help.
You can view SQL*Plus resources at http://otn.oracle.com/tech/sql_plus/
and the Oracle Database Library at http://otn.oracle.com/documentation/

HELP|? [topic]

SQL> help | create user
SP2-0172: No HELP matching this topic was found.
SQL> help createuser;
SP2-0172: No HELP matching this topic was found.
SQL> ? create user
SP2-0172: No HELP matching this topic was found.
SQL> help index

Enter Help [topic] for help.

@ COPY PAUSE SHUTDOWN
@@ DEFINE PRINT SPOOL
/ DEL PROMPT SQLPLUS
ACCEPT DESCRIBE QUIT START
APPEND DISCONNECT RECOVER STARTUP
ARCHIVE LOG EDIT REMARK STORE
ATTRIBUTE EXECUTE REPFOOTER TIMING
BREAK EXIT REPHEADER TTITLE
BTITLE GET RESERVED WORDS (SQL) UNDEFINE
CHANGE HELP RESERVED WORDS (PL/SQL) VARIABLE
CLEAR HOST RUN WHENEVER OSERROR
COLUMN INPUT SAVE WHENEVER SQLERROR
COMPUTE LIST SET
CONNECT PASSWORD SHOW

SQL> help show

SHOW
----

Shows the value of a SQL*Plus system variable, or the current
SQL*Plus environment. SHOW SGA requires a DBA privileged login.

SHO[W] option

where option represents one of the following terms or clauses:
system_variable
ALL
BTI[TLE]
ERR[ORS] [{FUNCTION | PROCEDURE | PACKAGE | PACKAGE BODY | TRIGGER
| VIEW | TYPE | TYPE BODY | DIMENSION | JAVA CLASS} [schema.]name]
LNO
PARAMETERS [parameter_name]
PNO
RECYC[LEBIN] [original_name]
REL[EASE]
REPF[OOTER]
REPH[EADER]
SGA
SPOO[L]
SQLCODE
TT[ITLE]
USER

SHOW SPOOL is not available in iSQL*Plus

SQL> desc system.help;
Name Null? Type
----------------------------------------- -------- ----------------------------
TOPIC NOT NULL VARCHAR2(50)
SEQ NOT NULL NUMBER
INFO VARCHAR2(80)

SQL> desc user_users;
Name Null? Type
----------------------------------------- -------- ----------------------------
USERNAME NOT NULL VARCHAR2(30)
USER_ID NOT NULL NUMBER
ACCOUNT_STATUS NOT NULL VARCHAR2(32)
LOCK_DATE DATE
EXPIRY_DATE DATE
DEFAULT_TABLESPACE NOT NULL VARCHAR2(30)
TEMPORARY_TABLESPACE NOT NULL VARCHAR2(30)
CREATED NOT NULL DATE
INITIAL_RSRC_CONSUMER_GROUP VARCHAR2(30)
EXTERNAL_NAME VARCHAR2(4000)

SQL>