dbms_output語句中的單引號？

Question

我需要在dbms_output語句中包含單引號。我已經試過這樣：

dbms_output.put_line('\''first_name||'\''); 

這裏FIRST_NAME正在variable;我需要在單引號內顯示​​。

Answer 1

你會加倍了逃避：

dbms_output.put_line('''' || first_name || ''''); 

或使用q-quote機制：

dbms_output.put_line(q'[']'||first_name||q'[']'); 

如：

SQL> var b1 varchar2(30) 
SQL> exec :b1 := 'this is a test'; 

PL/SQL procedure successfully completed. 

SQL> exec dbms_output.put_line(q'[']'||:b1||q'[']'); 
'this is a test' 

PL/SQL procedure successfully completed. 

SQL> exec dbms_output.put_line(''''||:b1||''''); 
'this is a test' 

PL/SQL procedure successfully completed. 

SQL> exec dbms_output.put_line(chr(39)||:b1||chr(39)); 
'this is a test' 

PL/SQL procedure successfully completed. 

Answer 2

請注意，這只是針對PL/SQL並且必須是積極的。

begin 
DBMS_OUTPUT.PUT_LINE('DELETE FROM MYTABLE WHERE MYFIELD <> ''A'';'); 
end; 
/

假設您想匹配CHAR'A'。