TSQL与PL/SQL的比较
以前一直用mssql 做开发，最近的项目都Oracle,
1)数据类型
|
|
TSQL |
PL/SQL |
|
|
numeric(p,s) |
numeric(p,s) or NUMBER(p,s) |
|
|
decimal(p,s) |
decimal(p,s) or NUMBER(p,s) |
|
|
char(m) |
Char(m) |
|
|
varchar(m) |
varchar2(m) |
|
|
datetime |
date |
|
记录 |
|
Record |
|
表字段 |
|
%type |
|
表记录 |
|
%rowtype |
|
表 |
|
Table |
|
自动增长变量 |
AUTOINCREMENT |
|
2)变量声明、赋值与引用
|
|
TSQL |
PL/SQL |
|
声明 |
declare @ls_casher char(1), @ln_payAmt decimal(14,4) |
declare on_hand INTEGER; ls_casher char(1); |
|
赋值 |
select @ls_casher = 'A' |
ls_casher:=’A’; |
|
引用 |
if @ ls_casher = 'A' … |
if ls_casher = 'A' then … |
|
在SQL语句中赋值 |
SELECT @ls_casher=sal FROM emp WHERE empno = emp_id; |
SELECT sal INTO ls_casher FROM emp WHERE empno = emp_id; |
|
在SQL语句中引用 |
SELECT * FROM emp WHERE sal = @ls_casher; |
SELECT * FROM emp WHERE sal = ls_casher; |
3)函数与操作符
字符串
|
|
TSQL |
PL/SQL |
|
连接 |
+ |
|| |
|
|
TRIM |
LTRIM、RTRIM |
|
|
SUBSTRING |
SUBSTR、SUBSTRB |
|
|
|
INSTR、INSTRB |
|
|
right(str,n) |
substr(str,-n) |
日期
|
|
TSQL |
PL/SQL |
|
系统日期 |
getdate() |
SYSDATE |
|
|
|
|
空值判断与处理
|
|
TSQL |
PL/SQL |
|
判断 |
IS NULL |
IS NULL |
|
空值替换 |
Isnull(para,0) |
NVL(para,0) REPLACE(old_string, NULL, my_string)
|
转换
|
|
TSQL |
PL/SQL |
|
字符->日期 |
Convert(datetime, expr, style) |
To_Date(format, expr) |
|
字符<-日期、数值 |
Convert(char(n), expr, style) |
To_char(expr,format) |
|
数值 |
|
To_Number() |
语句
|
|
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]
|
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 |
|
|
Comment |
-- /*…*/ |
-- /*…*/ |
|
|
PRINT string |
Set serveroutput on dbms_output.put_line(string); |
|
RAISERROR |
RAISERROR |
|
|
EXECUTE |
EXECUTE |
|
|
NULL statement |
|
NULL; |
4)cursor
|
|
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 |
|
|
隐式cursor |
|
Select…into (仅可处理单行记录) |
|
|
|
|
5)trigger
|
|
TSQL |
PL/SQL |
|
创建 |
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] … |
|
类型(按触发级别和时序) |
语句 after |
行或语句 before or after |
|
访问数据操纵行的值 |
通过表Inserted、Deleted访问 |
通过记录 :New、 :Old访问，仅可用于行级触发器 |
|
谓词/函数/属性 |
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 |
|
作为触发语句的一部分，不可用事务控制命令 不能声明和使用LONG、LONG RAW变量和列 |
|
删除 |
Drop trigger t_name |
Drop trigger t_name; |
6)procedure
|
|
TSQL |
PL/SQL |
|
创建 |
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} … |
|
查询 |
|
|
|
删除 |
DROP PROCEDURE p_name |
DROP PROCEDURE p_name; |
|
调用 |
EXEC p_name [para1[,…]] |
P_name[(para1[,…])]; |
|
参数 |
按位置传递 |
1)按位置传递 2)带名传递 P_name(para1=>var1);
debit_account(amount => 500, acct_id => 10261); |
7)数据字典/系统表
|
|
TSQL |
PL/SQL |
|
系统对象表 |
Dbo.sysobjects |
User_source、User_objects(OBJ)、User_tables(TABS)、User_triggers、ALL_tables、All_View、All_catalog、All_objects |
|
对象脚本 |
sp_helptext |
DESC、ALL_source |
|
用户表 |
Sysusers |
All_users |
|
表列 |
|
All_tab_columns |
|
依赖 |
|
All_dependencies |
|
字典表说明 |
|
DICT |
8)SQL
|
|
TSQL |
PL/SQL |
|
Select |
Select @var=<value>
|
Select value into var from dual
|
|
Insert |
insert / insert into |
insert into |
|
Delete |
|
|
|
比较 |
|
Any, some, all |
|
集合 |
|
Union、Union all、Intersect、Minus、 |
9)全局变量
|
|
TSQL |
PL/SQL |
|
语句执行成功 |
error |
SQLCODE |
|
select 是否有结果 |
exists |
select...into + SQL%FOUND |
10) 命令行查询工具
|
|
ISQL |
SQL PLUS |
|
读取、执行SQL文件 |
Isql –Usa –Ppass –Shost –ifile |
sqlplus [-s] user/pass@db -@filename |
|
|
|
|
|
|
|
|
|
|
|
|
11) 杂项
|
|
TSQL |
PL/SQL |
|
锁 |
在SQL语句中 Insert…With tablock Insert…With Tablockx Select…for update Select…for readonly 独立语句 set transcation isolation level to Read uncommited
|
在SQL语句中 select …for update of…;
独立语句 lock table tabname in row share mode; lock table tabname in share exclusive mode;
|
|
用户连接数 |
|
|
|
数据库文件 |
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;
|
|
显示DML执行计划 |
Show plan |
Explain plan |
|
保留点 |
¨ Save transcation Sp_name ¨ ROLLBACK TRANSACTION percentchanged |
¨ Savepoint Sp_name ¨ Rollback to savepoint sp_name |
|
对模式对象改名 |
Rename |
|
|
分析对象 |
Analyze |
Sp_help? |
|
|
|
|
1. select into 语法
现在有表
tablea
(
cola int ,
colb varchar(20)
)
要把tablea中满足条件(cola <100)的记录生成新的表tableb。
在ms sqlserver 可以直接用select into语法：
select * into tableb
where cola < 100
在oracle中语法如下：
create table tableb
as
(
select * from tablea
where cola <100
)
