全面對(duì)比T-SQL與PL/SQL
以前一直用mssql 做開(kāi)發(fā),最近的項(xiàng)目都Oracle,
1)數(shù)據(jù)類型
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TSQL |
PL/SQL |
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numeric(p,s) |
numeric(p,s) or NUMBER(p,s) |
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decimal(p,s) |
decimal(p,s) or NUMBER(p,s) |
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char(m) |
Char(m) |
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varchar(m) |
varchar2(m) |
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datetime |
date |
記錄 |
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Record |
表字段 |
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%type |
表記錄 |
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%rowtype |
表 |
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Table |
自動(dòng)增長(zhǎng)變量 |
AUTOINCREMENT |
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2)變量聲明、賦值與引用
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TSQL |
PL/SQL |
聲明 |
declare @ls_casher char(1), @ln_payAmt decimal(14,4) |
declare on_hand INTEGER; ls_casher char(1); |
賦值 |
select @ls_casher = 'A' |
ls_casher:=’A’; |
引用 |
if @ ls_casher = 'A' … |
if ls_casher = 'A' then … |
在SQL語(yǔ)句中賦值 |
SELECT @ls_casher=sal FROM emp WHERE empno = emp_id; |
SELECT sal INTO ls_casher FROM emp WHERE empno = emp_id; |
在SQL語(yǔ)句中引用 |
SELECT * FROM emp WHERE sal = @ls_casher; |
SELECT * FROM emp WHERE sal = ls_casher; |
3)函數(shù)與操作符
字符串
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TSQL |
PL/SQL |
連接 |
+ |
|| |
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TRIM |
LTRIM、RTRIM |
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SUBSTRING |
SUBSTR、SUBSTRB |
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INSTR、INSTRB |
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right(str,n) |
substr(str,-n) |
日期
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TSQL |
PL/SQL |
系統(tǒng)日期 |
getdate() |
SYSDATE |
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空值判斷與處理
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TSQL |
PL/SQL |
判斷 |
IS NULL |
IS NULL |
空值替換 |
Isnull(para,0) |
NVL(para,0) REPLACE(old_string, NULL, my_string)
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轉(zhuǎn)換
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TSQL |
PL/SQL |
字符->日期 |
Convert(datetime, expr, style) |
To_Date(format, expr) |
字符<-日期、數(shù)值 |
Convert(char(n), expr, style) |
To_char(expr,format) |
數(shù)值 |
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To_Number() |
語(yǔ)句
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TSQL |
PL/SQL |
statement block |
BEGIN...END |
BEGIN...END; |
conditional |
1) IF…ELSE… 2) IF…ELSE IF…else… 3) CASE |
1)IF..then...ELSE…end if; 2)If…then… elsif…else…endif 3)decode |
Repeat |
WHILE Boolean_expression {statement_block} [BREAK] {statement_block} [CONTINUE]
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1)Loop …exit;…end loop; 2)loop…exit when…end loop; 3)WHILE condition LOOP sequence_of_statements; EXIT WHEN boolean_expression; END LOOP; 3)for…in [reverse]…loop … end loop; |
GOTO |
GOTO label … label: … |
GOTO label; … <<label>> … |
Exits unconditionally |
RETURN |
Return; |
Sets a delay for statement execution |
WAITFOR |
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Comment |
-- /*…*/ |
-- /*…*/ |
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PRINT string |
Set serveroutput on dbms_output.put_line(string); |
RAISERROR |
RAISERROR |
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EXECUTE |
EXECUTE |
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NULL statement |
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NULL; |
4)cursor
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TSQL |
PL/SQL |
DECLARE |
DECLARE cursor_name CURSOR [LOCAL | GLOBAL] [FORWARD_ONLY | SCROLL] [STATIC | KEYSET | DYNAMIC | FAST_FORWARD] [READ_ONLY | SCROLL_LOCKS | OPTIMISTIC] [TYPE_WARNING] FOR select_statement [FOR UPDATE [OF column_name [,...n]]] |
DECLARE CURSOR cursor_name IS SELECT_statement; |
open |
Open cursor_name |
Open cursor_name; |
Fetch |
Fetch cursor_name into var1,var2… |
Fetch cursor_name into var1,var2… || %rowtype_var; |
Close |
Close cursor_name |
Close cursor_name; |
Attribute |
@@FETCH_STATUS @@CURSOR_ROWS CURSOR_STATUS |
%found %notfound %isopen %rowcount |
DEALLOCATE |
DEALLOCATE cursor_name |
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隱式cursor |
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Select…into (僅可處理單行記錄) |
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5)trigger
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TSQL |
PL/SQL |
創(chuàng)建 |
CREATE TRIGGER trigger_name ON table [WITH ENCRYPTION] {FOR {[DELETE][,][INSERT][,] [UPDATE] } AS sql_statement [...n] } |
Create or replace trigger t_name {before|after}{insert|update|delete} on table_name [for each row [when conditional] … |
類型(按觸發(fā)級(jí)別和時(shí)序) |
語(yǔ)句 after |
行或語(yǔ)句 before or after |
訪問(wèn)數(shù)據(jù)操縱行的值 |
通過(guò)表Inserted、Deleted訪問(wèn) |
通過(guò)記錄 :New、 :Old訪問(wèn),僅可用于行級(jí)觸發(fā)器 |
謂詞/函數(shù)/屬性 |
Inserting、updating、deleteing Updating(col) |
Update(col) |
使能 |
Alter table tabname {disable|enable} trigger {t_name|all} |
Alter trigger t_name {disable|enable} |
限制 |
|
作為觸發(fā)語(yǔ)句的一部分,不可用事務(wù)控制命令 不能聲明和使用LONG、LONG RAW變量和列 |
刪除 |
Drop trigger t_name |
Drop trigger t_name; |
6)procedure
|
TSQL |
PL/SQL |
創(chuàng)建 |
CREATE PROCEDURE] p_name [ {@parameter data_type} [VARYING] [= default] [OUTPUT] ] [,...n] [WITH { RECOMPILE | ENCRYPTION | RECOMPILE, ENCRYPTION } ] AS sql_statement [...n] |
Create or replace procedure p_name [Para1 {in|out|inout} datatype[,…] [{:=|default} default_value]] {IS|AS} … |
查詢 |
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刪除 |
DROP PROCEDURE p_name |
DROP PROCEDURE p_name; |
調(diào)用 |
EXEC p_name [para1[,…]] |
P_name[(para1[,…])]; |
參數(shù) |
按位置傳遞 |
1)按位置傳遞 2)帶名傳遞 P_name(para1=>var1);
debit_account(amount => 500, acct_id => 10261); |
7)數(shù)據(jù)字典/系統(tǒng)表
|
TSQL |
PL/SQL |
系統(tǒng)對(duì)象表 |
Dbo.sysobjects |
User_source、User_objects(OBJ)、User_tables(TABS)、User_triggers、ALL_tables、All_View、All_catalog、All_objects |
對(duì)象腳本 |
sp_helptext |
DESC、ALL_source |
用戶表 |
Sysusers |
All_users |
表列 |
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All_tab_columns |
依賴 |
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All_dependencies |
字典表說(shuō)明 |
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DICT |
8)SQL
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TSQL |
PL/SQL |
Select |
Select @var=<value>
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Select value into var from dual
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Insert |
insert / insert into |
insert into |
Delete |
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比較 |
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Any, some, all |
集合 |
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Union、Union all、Intersect、Minus、 |
9)全局變量
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TSQL |
PL/SQL |
語(yǔ)句執(zhí)行成功 |
error |
SQLCODE |
select 是否有結(jié)果 |
exists |
select...into + SQL%FOUND |
10) 命令行查詢工具
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ISQL |
SQL PLUS |
讀取、執(zhí)行SQL文件 |
Isql –Usa –Ppass –Shost –ifile |
sqlplus [-s] user/pass@db -@filename |
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11) 雜項(xiàng)
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TSQL |
PL/SQL |
鎖 |
在SQL語(yǔ)句中 Insert…With tablock Insert…With Tablockx Select…for update Select…for readonly 獨(dú)立語(yǔ)句 set transcation isolation level to Read uncommited
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在SQL語(yǔ)句中 select …for update of…;
獨(dú)立語(yǔ)句 lock table tabname in row share mode; lock table tabname in share exclusive mode;
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用戶連接數(shù) |
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數(shù)據(jù)庫(kù)文件 |
Device |
Tablespace
CREATE TABLESPACE testdb DATAFILE 'C:\ORANT\DATABASE\testdb.ORA' SIZE 20M AUTOEXTEND ON NEXT 2M; CREATE ROLLBACK SEGMENT "RB_TESTDB" TABLESPACE "TESTDB"; ALTER ROLLBACK SEGMENT "RB_TESTDB" ONLINE;
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顯示DML執(zhí)行計(jì)劃 |
Show plan |
Explain plan |
保留點(diǎn) |
¨ Save transcation Sp_name ¨ ROLLBACK TRANSACTION percentchanged |
¨ Savepoint Sp_name ¨ Rollback to savepoint sp_name |
對(duì)模式對(duì)象改名 |
Rename |
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分析對(duì)象 |
Analyze |
Sp_help? |
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1. select into 語(yǔ)法
現(xiàn)在有表
tablea
(
cola int ,
colb varchar(20)
)
要把tablea中滿足條件(cola <100)的記錄生成新的表tableb。
在ms sqlserver 可以直接用select into語(yǔ)法:
select * into tableb
where cola < 100
在oracle中語(yǔ)法如下:
create table tableb
as
(
select * from tablea
where cola <100
)
posted on 2012-08-16 08:46 奮斗成就男人 閱讀(519) 評(píng)論(0) 編輯 收藏 所屬分類: SQL