oracle 入门常见问题

解锁用户：

alter user scott identified by tiger account unlock;

修改字符集：

alter session set NLS_DATE_LANGUAGE = 'AMERICAN' ; 或'Simplified Chinese';

重建scott用户和它所拥有的一切：

@%ORACLE_HOME\RDDMS\ADMIN\scott.sql;

修改列属性：col 列名 for

col hiredata for a15;

col ename for a8

获得iSQL*Plus服务的HTTP端口号：

打开%ORACLE_HOME%\install\portlist.ini 文件。

忘记system/sys的密码：

删掉%ORACLE_HOME%/database/pwdtestdb.ora;

使用命令：orapwd file=d:/pwdtestdb.ora password=admin1 entries=10;将密码设置为admin1；

或则：

sqlplus /@testdb as sysdba

alter user sys identified by 新密码;

alter user system identified by 新密码;

脚本启动服务：

如新建start_services.bat文件，并写入：
net start OracleServiceORCL

net start OracleDBConsoleorcl

net start OracleOraDb10g_home1iSQL*Plus

net start OracleOraDb10g_home1TNSListener
保存后，右键该文件以管理员身份运行。
net start OracleOraDb10g_home1TNSListener 和 lsnrctl start 一样。
net start OracleOraDb10g_home1iSQL*Plus 和 isqlplusctl start 一样。

查询语句：

SELECT *|{[DISTINCT] 列名…}
FROM 表名
[WHERE 条件]
[ORDER BY {列名|别名|表达式,…}[ASC|DESC]];
语句：一条完整的SQL命令
子句：关键字和后面的选项
条件：
列名、字符串、常量、算术表达式和比较运算符。
字符串和日期用单引号括起来

算术运算符：

+、-、*、/

比较运算符：

>、>=、<、<=、=、!=或<>、AND、IN、LIKE

另外，还有NOT

BETWEEN AND包含上限和下限

通配符（wildcard):

%:代表0个或多个字符

_:代表一个且只能是一个字符

SELECT * FROM emp WHERE job LIKE 'S_\_L%' escape '\';

转义操作符 escape '\'

order by 一定是SQL语句的最后一个子句

SQL*PLUS命令：

@	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

@ ("at" sign)

-------------

Runs the SQL*Plus statements in the specified script. The script can

called from the local file system or a web server. Only the url form

supported in iSQL*Plus.

@ {url|file_name[.ext]} [arg ...]

where url supports HTTP and FTP protocols in the form:

http://host.domain/script.sql

@@ (double "at" sign)

---------------------

Runs the specified script. This command is almost identical to

the @ command. It is useful for running nested scripts because it

has the additional functionality of looking for the nested script

in the same url or path as the calling script. Only the url form

is supported in iSQL*Plus.

@@ {url|file_name[.ext]} [arg ...]

/ (slash)

---------

Executes the most recently executed SQL command or PL/SQL block

which is stored in the SQL buffer. Use slash (/) at the command

prompt or line number prompt in SQL*Plus command line, or use

slash (/) in the iSQL*Plus Workspace. The buffer has no command

history and does not record SQL*Plus commands.

/

ACCEPT

------

Reads a line of input and stores it in a given substitution variable.

In iSQL*Plus, displays the Input Required screen for you to enter a

value for the substitution variable.

ACC[EPT] variable [NUM[BER] | CHAR | DATE | BINARY_FLOAT | BINARY_DOUBLE]

[FOR[MAT] format] [DEF[AULT] default] [PROMPT text | NOPR[OMPT]] [HIDE]

APPEND

------

Adds text to the end of the current line in the SQL buffer.

A[PPEND] text

Not available in iSQL*Plus

ARCHIVE LOG

-----------

Starts or stops automatic archiving of online redo log files,

manually (explicitly) archives specified redo log files, or

displays information about redo log files.

ARCHIVE LOG {LIST|STOP} | {START|NEXT|ALL|integer} [TO destination]

BREAK

-----

Specifies where changes occur in a report and the formatting

action to perform, such as:

- suppressing display of duplicate values for a given column

- skipping a line each time a given column value changes

(In iSQL*Plus, only when Preformatted Output is ON)

- printing computed figures each time a given column value

changes or at the end of the report.

Enter BREAK with no clauses to list the current BREAK definition.

BRE[AK] [ON report_element [action [action]]] ...

where report_element has the following syntax:

{column | expression | ROW | REPORT}

and where action has the following syntax:

[SKI[P] n | [SKI[P]] PAGE] [NODUP[LICATES] | DUP[LICATES]]

The SKIP option is not supported in iSQL*Plus

BTITLE

------

Places and formats a specified title at the bottom of each report

page, or lists the current BTITLE definition.

BTI[TLE] [printspec [text|variable] ...] | [OFF|ON]

where printspec represents one or more of the following clauses:

COL n LE[FT] BOLD

S[KIP]
CE[NTER] FORMAT text

TAB n R[IGHT]

CHANGE

------

Changes the first occurrence of the specified text on the current

line of the SQL buffer. The buffer has no command history list and

does not record SQL*Plus commands.

C[HANGE] sepchar old [sepchar [new[sepchar]]]

Not available in iSQL*Plus

CLEAR

-----

Resets or erases the current value or setting for the specified option.

CL[EAR] option ...

where option represents one of the following clauses:

BRE[AKS]

BUFF[ER]

COL[UMNS]

COMP[UTES]

SCR[EEN]

SQL

TIMI[NG]

CLEAR SCREEN is not available in iSQL*Plus

COLUMN

------

Specifies display attributes for a given column, such as:

- text for the column heading

- alignment for the column heading

- format for NUMBER data

- wrapping of column data

Also lists the current display attributes for a single column

or all columns.

COL[UMN] [{column | expr} [option ...] ]

where option represents one of the following clauses:

ALI[AS] alias

CLE[AR]

ENTMAP {ON|OFF}

FOLD_A[FTER]

FOLD_B[EFORE]

FOR[MAT] format

HEA[DING] text

JUS[TIFY] {L[EFT] | C[ENTER] | R[IGHT]}

LIKE {expr | alias}

NEWL[INE]

NEW_V[ALUE] variable

NOPRI[NT] | PRI[NT]

NUL[L] text

OLD_V[ALUE] variable

ON|OFF

WRA[PPED] | WOR[D_WRAPPED] | TRU[NCATED]

COMPUTE

-------

In combination with the BREAK command, calculates and prints

summary lines using various standard computations. Also lists

all COMPUTE definitions.

COMP[UTE] [function [LAB[EL] text] ...

OF {expr|column|alias} ...

ON {expr|column|alias|REPORT|ROW} ...]

CONNECT

-------

Connects a given username to the Oracle Database. When you run a

CONNECT command, the site profile, glogin.sql, and the user profile,

login.sql, are processed in that order. CONNECT does not reprompt

for username or password if the initial connection does not succeed.

CONN[ECT] [{logon|/|proxy} [AS {SYSOPER|SYSDBA}]]

where logon has the following syntax:

username[/password][@connect_identifier]

DEFINE

------

Specifies a substitution variable and assigns a CHAR value to it, or

lists the value and variable type of a single variable or all variables.

DEF[INE] [variable] | [variable = text]

DEL

---

Deletes one or more lines of the SQL buffer. The buffer has no

command history list and does not record SQL*Plus commands.

DEL [n | n m | n * | n LAST | * | * n | * LAST | LAST]

Not available in iSQL*Plus

DESCRIBE

--------

Lists the column definitions for a table, view, or synonym,

or the specifications for a function or procedure.

DESC[RIBE] {[schema.]object[@connect_identifier]}

Commits pending changes to the database and logs the current

user out of Oracle, but does not exit SQL*Plus.

In SQL*Plus command line, use EXIT or QUIT to log out of Oracle

and return control to your computer's operating system.

In iSQL*Plus, click the Logout button to log out of Oracle.

DISC[ONNECT]

EDIT

----

Invokes an operating system text editor on the contents of the

specified file or on the contents of the SQL buffer. The buffer

has no command history list and does not record SQL*Plus commands.

ED[IT] [file_name[.ext]]

Not available in iSQL*Plus

QL> help execute

EXECUTE

-------

Executes a single PL/SQL statement or runs a stored procedure.

EXEC[UTE] statement

GET

---

Loads a SQL statement or PL/SQL block from a script into the SQL buffer.

In iSQL*Plus click the Load Script button to load a script into the

Workspace. The buffer has no command history list and does not record

SQL*Plus commands.

GET [FILE] file_name[.ext] [LIST | NOLIST]

Not available in iSQL*Plus

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]

Executes an operating system command without leaving SQL*Plus.

Enter HOST without command to display an operating system prompt.

You can then enter multiple operating system commands.

HO[ST] [command]

Not available in iSQL*Plus

INPUT

-----

Adds one or more new lines of text after the current line in the

SQL buffer. The buffer has no command history list and does not

record SQL*Plus commands.

I[NPUT] [text]

Not available in iSQL*Plus

LIST

----

Lists one or more lines of the most recently executed SQL command

or PL/SQL block which is stored in the SQL buffer. Enter LIST with

no clauses to list all lines. In SQL*Plus command-line you can also

use ";" to list all the lines in the SQL buffer. The buffer has no

command history list and does not record SQL*Plus commands.

L[IST] [n | n m | n * | n LAST | * | * n | * LAST | LAST]

PASSWORD

--------

Allows you to change a password without displaying it on an input device.

In iSQL*Plus, use the Password screen to change your password.

PASSW[ORD] [username]

Not available in iSQL*Plus

PAUSE

-----

Displays the specified text then waits for the user to press RETURN.

In iSQL*Plus, displays the Next Page button which the user must click

to continue.

PAU[SE] [text]

PROMPT

------

Sends the specified message or a blank line to the user's screen.

PRO[MPT] [text]

QUIT (Identical to EXIT)

----

Commits or rolls back all pending changes, logs out of Oracle,

terminates SQL*Plus and returns control to the operating system.

In iSQL*Plus, commits or rolls back all pending changes, stops

processing the current iSQL*Plus script and returns focus to the

Workspace. There is no way to access the return code in iSQL*Plus.

In iSQL*Plus click the Logout button to log out of Oracle Database.

{QUIT|EXIT} [SUCCESS|FAILURE|WARNING|n|variable|:BindVariable]

[COMMIT|ROLLBACK]

RECOVER

-------

Performs media recovery on one or more tablespaces, one or more

datafiles, or the entire database.

Because of possible network timeouts, it is recommended that you

use SQL*Plus command-line, not iSQL*Plus, for long running DBA

operations such as RECOVER.

RECOVER {general | managed} | BEGIN BACKUP | END BACKUP}

where the general clause has the following syntax:

[AUTOMATIC] [FROM location]

{ {full_database_recovery | partial_database_recovery |LOGFILE filename}

[ {TEST | ALLOW integer CORRUPTION | parallel_clause}

[TEST | ALLOW integer CORRUPTION | parallel_clause] ...]

|CONTINUE [DEFAULT]|CANCEL}

where the full_database_recovery clause has the following syntax:

[STANDBY] DATABASE

[{ UNTIL {CANCEL | TIME date | CHANGE integer}

| USING BACKUP CONTROLFILE}

[ UNTIL {CANCEL | TIME date | CHANGE integer}

| USING BACKUP CONTROLFILE] ...]

where the partial_database_recovery clause has the following syntax:

{TABLESPACE tablespace [, tablespace] ...

| DATAFILE filename | filenumber} [,filename | filenumber] ...

| STANDBY

{TABLESPACE tablespace [, tablespace] ...

| DATAFILE filename | filenumber} [,filename | filenumber] ...}

UNTIL [CONSISTENT WITH] CONTROLFILE }

where the parallel clause has the following syntax:

{NOPARALLEL | PARALLEL [integer]}

where the managed clause has the following syntax:

MANAGED STANDBY DATABASE recover_clause | cancel_clause | finish_clause

where the recover_clause has the following syntax:

{{DISCONNECT [FROM SESSION] | {TIMEOUT integer | NOTIMEOUT} }

|{NODELAY | DEFAULT DELAY | DELAY integer} | NEXT integer

|{EXPIRE integer | NO EXPIRE} | parallel_clause

| USING CURRENT LOGFILE | UNTIL CHANGE integer

| THROUGH {[THREAD integer] SEQUENCE integer

| ALL ARCHIVELOG | {ALL | LAST | NEXT } SWITCHOVER} }

[DISCONNECT [FROM SESSION ] | {TIMEOUT integer | NOTIMEOUT}

| {NODELAY | DEFAULT DELAY | DELAY integer} | NEXT integer

| {EXPIRE integer | NO EXPIRE} | parallel_clause

| USING CURRENT LOGFILE | UNTIL CHANGE integer

| THROUGH {[THREAD integer] SEQUENCE integer

| ALL ARCHIVELOG | {ALL | LAST | NEXT } SWITCHOVER} ]...

where the cancel_clause has the following syntax:

CANCEL [IMMEDIATE] [WAIT | NOWAIT]

where the finish_clause has the following syntax:

[DISCONNECT [FROM SESSION]] [parallel_clause]

FINISH [SKIP [STANDBY LOGFILE]] [WAIT | NOWAIT]

where the parallel_clause has the following syntax:

{NOPARALLEL | PARALLEL [integer] }

REMARK

------

Begins a comment in a script. SQL*Plus does not interpret the comment

as a command.

REPFOOTER

---------

Places and formats a footer at the bottom of a report, or lists the

REPFOOTER definition.

REPF[OOTER] [PAGE] [printspec [text|variable] ...] | [OFF|ON]

where printspec represents one or more of the following clauses:

COL n LE[FT] BOLD

S[KIP]
CE[NTER] FORMAT text

TAB n R[IGHT]

REPHEADER

---------

Places and formats a header at the top of a report, or lists the

REPHEADER definition.

REPH[EADER] [PAGE] [printspec [text|variable] ...] | [OFF|ON]

where printspec represents one or more of the following clauses:

COL n LE[FT] BOLD

S[KIP]
CE[NTER] FORMAT text

TAB n R[IGHT]

RESERVED WORDS (SQL)

--------------------

SQL Reserved Words have special meaning in SQL, and may not be used for

identifier names unless enclosed in "quotes".

An asterisk (*) indicates words are also ANSI Reserved Words.

Oracle prefixes implicitly generated schema object and subobject names

with "SYS_". To avoid name resolution conflict, Oracle discourages you

from prefixing your schema object and subobject names with "SYS_".

RUN

---

Lists and executes the most recently executed SQL command or

PL/SQL block which is stored in the SQL buffer. The buffer has

no command history list and does not record SQL*Plus commands.

R[UN]

SAVE

----

Saves the contents of the SQL buffer in a script. In iSQL*Plus, click

the Save Script button to save the Workspace contents to a script. The

buffer has no command history list and does not record SQL*Plus commands.

SAV[E] [FILE] file_name[.ext] [CRE[ATE] | REP[LACE] | APP[END]]

Not available in iSQL*Plus

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

SHUTDOWN

--------

Shuts down a currently running Oracle Database instance, optionally

closing and dismounting a database.

SHUTDOWN [ABORT|IMMEDIATE|NORMAL|TRANSACTIONAL [LOCAL]]

SPOOL

-----

Stores query results in a file, or optionally sends the file to a printer.

In iSQL*Plus, use the Preferences screen to direct output to a file.

SPO[OL] [file_name[.ext] [CRE[ATE] | REP[LACE] | APP[END]] | OFF | OUT]

Not available in iSQL*Plus

SQLPLUS

-------

Starts SQL*Plus from the operating system prompt.

SQLPLUS [ [option] [logon] [start] ]

where option has the following syntax:

-H[ELP]

| -V[ERSION]

| [[-C[OMPATIBILITY] x.y[.z]] [-L[OGON]]

[-M[ARKUP] markup_option] [-R[ESTRICT] {1|2|3}] [-S[ILENT]]]

and where markup_option has the following syntax:

HTML [ON|OFF] [HEAD text] [BODY text] [TABLE text]

[ENTMAP {ON|OFF}] [SPOOL {ON|OFF}] [PRE[FORMAT] {ON|OFF}]

and where logon has the following syntax:

{username[/password][@connect_identifier] | /}

[AS {SYSOPER|SYSDBA}] | /NOLOG

and where start has the following syntax:

@{url|filename[.ext]} [arg ...]

START

-----

Runs the SQL*Plus statements in the specified script. The script can be

called from the local file system or a web server. Only the url form is

supported in iSQL*Plus.

STA[RT] {url|file_name[.ext]} [arg ...]

where url supports HTTP and FTP protocols in the form:

http://host.domain/script.sql

STARTUP

-------

Starts an Oracle instance with several options, including mounting,

and opening a database.

STARTUP options | upgrade_options

where options has the following syntax:

[FORCE] [RESTRICT] [PFILE=filename] [QUIET] [ MOUNT [dbname] |

[ OPEN [open_options] [dbname] ] |

NOMOUNT ]

where open_options has the following syntax:

READ {ONLY | WRITE [RECOVER]} | RECOVER

and where upgrade_options has the following syntax:

[PFILE=filename] {UPGRADE | DOWNGRADE} [QUIET]

STORE

-----

Saves attributes of the current SQL*Plus environment in a script.

STORE {SET} file_name[.ext] [CRE[ATE] | REP[LACE] | APP[END]]

Not available in iSQL*Plus

TTITLE

------

Places and formats a title at the top of each report page.

Enter TTITLE with no clause to list its current definition.

The old form of TTITLE is used if only a single word or

a string in quotes follows the TTITLE command.

TTI[TLE] [printspec [text|variable] ...] | [OFF|ON]

where printspec represents one or more of the following clauses:

COL n LE[FT] BOLD

S[KIP]
CE[NTER] FORMAT text

TAB n R[IGHT]

UNDEFINE

--------

Deletes one or more substitution variables that you defined either

explicitly (with the DEFINE command), or implicitly (with a START

command argument).

UNDEF[INE] variable ...

VARIABLE

--------

Declares a bind variable that can be referenced in PL/SQL, or

lists the current display characteristics for a single variable

or all variables.

AR[IABLE] [variable [type]]

where type represents one of the following:

NUMBER CHAR CHAR (n [CHAR|BYTE])

NCHAR NCHAR (n) VARCHAR2 (n [CHAR|BYTE])

NVARCHAR2 (n) CLOB NCLOB

REFCURSOR BINARY_FLOAT BINARY_DOUBLE

WHENEVER OSERROR

----------------

Performs the specified action (exits SQL*Plus by default) if an

operating system error occurs (such as a file writing error).

In iSQL*Plus, performs the specified action (stops the current

script by default) and returns focus to the Workspace if an

operating system error occurs.

WHENEVER OSERROR {EXIT [SUCCESS|FAILURE|n|variable|:BindVariable]

[COMMIT|ROLLBACK] | CONTINUE [COMMIT|ROLLBACK|NONE]}

WHENEVER SQLERROR

-----------------

Performs the specified action (exits SQL*Plus by default) if a

SQL command or PL/SQL block generates an error.

In iSQL*Plus, performs the specified action (stops the current

script by default) and returns focus to the Workspace if a SQL

command or PL/SQL block generates an error.

WHENEVER SQLERROR {EXIT [SUCCESS|FAILURE|WARNING|n|variable|:BindVariable]

[COMMIT|ROLLBACK] | CONTINUE [COMMIT|ROLLBACK|NONE]}