1.类型对比
| oracle | mysql |
|
int |
int |
|
number(6,2) |
decimal(6,2) |
|
date （sysdate） |
timestamp (now()) |
| varchar2(20) |
varchar(20) |
2.常用函数
/* DATE_FORMAT(date,format) 根据format字符串格式化date值 */ select date_format(‘2013-09-21 14:01:20‘,‘%Y-%m-%d %H:%i:%s‘) from dual; select case 2 when 1 then 1 when 2 then 2 else 0 end from dual; select IFNULL(null,0) from dual;
3.分页
从第10条记录开始检索20条记录
select * from sys_option limit 10,20; select * from table [查询条件] order by id limit ?,?;
以下语句是先排序后的分页（很好）
SELECT * FROM test_yutong ORDER BY ID DESC LIMIT 0,1;
order只能这么实现（没有mysql方便）
SELECT * FROM(SELECT * FROM TABLE_A ORDER BY ID DESC)B WHERE ROWNUM=1;
4.自定义序列函数（来源 http://www.oschina.net/code/snippet_110375_12231）
/* CREATE TABLE Sequence */ DROP TABLE IF EXISTS Sequence; CREATE TABLE Sequence ( name VARCHAR(32), maxIndex INTEGER, CONSTRAINT cst_Sequence_pk PRIMARY KEY (name, maxIndex) ); /* FUNCTION nextval */ SET GLOBAL log_bin_trust_function_creators = 1; DROP FUNCTION IF EXISTS nextval; DELIMITER // CREATE FUNCTION nextval(sequenceName VARCHAR(32)) RETURNS INTEGER NOT DETERMINISTIC CONTAINS SQL BEGIN DECLARE iMaxIndex INTEGER; UPDATE Sequence SET maxIndex = maxIndex + 1 WHERE name = sequenceName; SELECT maxIndex INTO iMaxIndex FROM Sequence WHERE name = sequenceName; RETURN iMaxIndex; END // DELIMITER ;
/* 测试例子 */ INSERT INTO Sequence(NAME,maxIndex)VALUES(‘CK10_GHDJ‘,1); SELECT nextval(‘CK10_GHDJ‘)FROM DUAL; SELECT * FROM Sequence;
时间： 2024-12-26 19:05:37