[20170929]& 代替冒号绑定变量.txt

--//我昨天看链接,

--//重复测试:

SCOTT@book> @ &r/ver1

PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

set def off serverout on

exec declare s varchar2(1); begin execute immediate 'select 1 from dual where dummy=&var' into s using 'X'; dbms_output.put_line(s); end;

--//正常&var 应该写成 :var ,而这里使用&var,按照以前,这里会替换定义的变量值,而不是变成绑定变量.

--//注:执行时要设置set def off serverout on,不然没有输出,并且还是要输入变量.

SCOTT@book> set def off serverout on

SCOTT@book> exec declare s varchar2(1); begin execute immediate 'select 1 from dual where dummy=&var' into s using 'X'; dbms_output.put_line(s); end; 1 PL/SQL procedure successfully completed.

SCOTT@book> select substr(sql_text,1,40) stext,sql_id,executions,rows_processed from v$sqlarea a where sql_text like '%dual%&var';

STEXT                                SQL_ID        EXECUTIONS ROWS_PROCESSED ------------------------------------ ------------- ---------- -------------- select 1 from dual where dummy=&var  ckkw4u3atxz02          1              1 --//注意看sql文本格式.

SCOTT@book> set def on serverout off

SCOTT@book> @ &r/dpc ckkw4u3atxz02 ''

PLAN_TABLE_OUTPUT ------------------------------------- SQL_ID  ckkw4u3atxz02, child number 0 ------------------------------------- select 1 from dual where dummy=&var Plan hash value: 272002086 --------------------------------------------------------------------------- | Id  | Operation         | Name | E-Rows |E-Bytes| Cost (%CPU)| E-Time   | --------------------------------------------------------------------------- |   0 | SELECT STATEMENT  |      |        |       |     2 (100)|          | |*  1 |  TABLE ACCESS FULL| DUAL |      1 |     2 |     2   (0)| 00:00:01 | --------------------------------------------------------------------------- Query Block Name / Object Alias (identified by operation id): -------------------------------------------------------------    1 - SEL$1 / DUAL@SEL$1 Peeked Binds (identified by position): --------------------------------------    1 - (CHAR(30), CSID=852): 'X' Predicate Information (identified by operation id): ---------------------------------------------------    1 - filter("DUMMY"=:VAR)