使用SELECT * FROM students时,SELECT是关键字,表示将要执行一个查询,*表示“所有列”,FROM表示将要从哪个表查询,本例中是students表。 该SQL将查询出students表的所有数据。注意:查询结果也是一个二维表,它包含列名和每一行的数据。 要查询classes表的所有行,我们用如下SQL语句: 代码语言:javascript 代码运行次数:0...
create profile文件名limit failed_logon_attempts3password_lock_time2 ---设置用户名输错3次账号锁定2天,2天后才能使用 alert user用户名profile文件名 ---分配文件(把输错次数就锁用户的方法分配给某个用户(完成输入错误3次锁2天)) ---(2)账号解锁 alter user用户名account unlock---被锁的用户进行解锁 ...
9 dbms_output.put_line('数字或值错误 : 数值精度太高'); 10 WHEN OTHERS THEN 11 dbms_output.put_line(SQLCODE); 12 dbms_output.put_line(substr(SQLERRM,1,100)); 13 END; 14 / 数字或值错误 : 数值精度太高 PL/SQL procedure successfully completed SQL> 2.RAISE_APPLICATION_ERROR 功能用来自定...
SQL>--声明部分SQL>declare2--说明部分3begin4--程序部分5dbms_output.put_line('Hello World');6end;7--退出编辑环境,并执行PL/SQL程序8/PL/SQL过程已成功完成。SQL>--默认情况下,Oracle的输出开关是关闭的。SQL>--如果要在屏幕上输出信息,需要将 serveroutput开关打开setserveroutput onSQL>setserveroutput...
SET HISTORY LIMIT N allows you to change the default limit, where N is the maximum number. History is retained between SQLcl sessions. By default, the SHOW, HISTORY, CONNECT, and SET commands are not saved in history. SET HISTORY BLACKLIST allows you to set the commands that should not ...
FORMAT BUFFER - formats the script in the SQLcl Buffer FORMAT RULES <filename> - Loads SQLDeveloper Formatter rules file to formatter FORMAT FILE <input_file> <output_file> GET file_name[.ext] [LIST | NOLIST] Loads a SQL statement or PL/SQL block from a file into the SQL buffer...
When executing scripts in SQL Developer, the amount of output we display on the screen is LIMITED. By design, we only show you 5,000 records from any query, and we limit the amount of output in total for a single script execution to 10,010 rows. This is
DBMS_OUTPUT.PUT_LINE('数据库中没有编码为'||v_empno||'的员工'); WHEN TOO_MANY_ROWS THEN DBMS_OUTPUT.PUT_LINE('程序运行错误!请使用游标'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE(SQLCODE||'---'||SQLERRM); END; 1. 2. 3. 4. ...
select tab.owner,tab.table_name,tab.blocks,tab.num_rows,ind.index_name,ind.clustering_factor, round(nvl(ind.clustering_factor,1)/decode(tab.num_rows,0,1,tab.num_rows),3)*100||'%' "集群因子接近行数" from dba_tables tab, dba_indexes ind where tab.table_name=ind.table_name and tab...
Directory created.SQL> create table alert_logs(text varchar2(2000))organization external(type oracle_loaderdefault directory bdumpaccess parameters(records delimited by newlinefieldsreject rows with all null fields)location('alert_GSP.log'))reject limit unlimited;Table created.SQL> select * from ...