1.SELECT select_list FROM table WHERE expr operater (SELECT select_list FROM table); 1)Expr operater包括比較子: 單行運算子(=、>、>=、<、<=、<>) 多行運算子(IN、ANY、ALL) 2)子查詢可以嵌於一下SQL子句中: WHERE 子句 HAVING 子句
--刪除括弧內的東西function delmatch(str in varchar2, firstmatch in varchar2, aftermatch in varchar2) return varchar2 is p1 integer; p2 integer; delstr varchar2(4000); begin p1 := instr(str,
--1.ASCII返回與指定的字元對應的十進位數;select ascii('A') A, ascii('a') a, ascii('0') zero, ascii(' ') space from dual;--返回: 65 97 48 32--2.CHR給出整數,返回對應的字元;select chr(54740) zhao, chr(65) chr65 from dual;--返回:趙 A--3.CONCAT串連兩個字串;select
預存程序建立文法:create or replace procedure 預存程序名(param1 in type,param2 out type) as 變數1 類型(值範圍);變數2 類型(值範圍);Begin Select count(*) into 變數1 from 表A where列名=param1; If (判斷條件) then Select 列名 into 變數2 from 表A where列名=param1; Dbms_output。Put_
如果控制檔案丟失或者損壞了,如何解決這個問題?查看參數檔案中的設定:SQL> show parameter CONTROL_FILES ;NAME TYPE VALUE------------------------------------ ----------- ------------------------------control_files string
文章目錄 何為閃回恢複區為何要用閃回恢複區?設定閃回恢複區 何為閃回恢複區按照Oracle官方文檔的解釋:Flash Recovery AreaThe flash recovery area is an Oracle-managed directory, file system, or Automatic Storage Management disk group that provides a centralized disk