MySql和Oracle数据库sql语句总结

1、建表语句

• MySQL

DROP TABLE IF EXISTS `class`;
CREATE TABLE `class`  (
  `id` int(11) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

• Oracle

DROP TABLE "SCOTT"."class";
CREATE TABLE "SCOTT"."class" (
  "id" NUMBER NOT NULL ,
  "name" VARCHAR2(255 BYTE) NOT NULL 
)

2、插入语句

• MySQL

INSERT INTO `class` VALUES (1001, '数学1班');
INSERT INTO `class` VALUES (1002, '数学2班');
INSERT INTO `class` VALUES (1003, '数学3班');

• Oracle

INSERT INTO "SCOTT"."class" VALUES ('101', '数学1班');
INSERT INTO "SCOTT"."class" VALUES ('102', '数学2班');
INSERT INTO "SCOTT"."class" VALUES ('103', '数学3班');

3、修改语句

• MySQL

UPDATE class SET name='计算机1班' WHERE id=1004;

• Oracle

UPDATE "SCOTT"."class" SET "class"."name"='数学5班' WHERE "class"."id"=105;

4、删除语句

• MySQL

DELETE FROM class WHERE id = 1004;

• Oracle

DELETE "SCOTT"."class" WHERE "class"."id"=105;

5、查询语句

• MySQL

SELECT c.*,COUNT(s.class) count
FROM class c LEFT JOIN student s ON c.id=s.class
GROUP BY c.id,c.name
ORDER BY c.id

• Oracle（连接可使用join或(+)实现）

SELECT c.*,COUNT(s."class") count
FROM "SCOTT"."class" c, "SCOTT"."student" s
WHERE c."id" = s."class"(+)
GROUP BY c."id",c."name"
ORDER BY c."id"

6、分页查询

• MySQL

SELECT * FROM class LIMIT 0,2

• Oracle

SELECT * 
FROM (SELECT ROWNUM r,a.*
	FROM(SELECT * FROM "class") a
	WHERE ROWNUM < 3) b
WHERE b.r > 0

7、MySQL与Oracle的区别

7.1 数据类型

MySQL	Oracle
int	number
varchar	varchar2

7.2 delete语句

• Oracle可以省略from

delete [from] 表名 where 属性=值

7.3 连接

• MySQL使用left join（right join）... on ...实现
• Oracle可以使用left join（right join）... on ...和(+)实现

7.4 连接

• MySQL直接使用limit实现
• Oracle没有limit，实现比MySQL稍微复杂一点：

SELECT * 
FROM (SELECT ROWNUM r,a.*
   FROM(SELECT * FROM "class") a
   WHERE ROWNUM < 3) b
WHERE b.r > 0