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MySQL与Oracle 差异比较之八其它

2014-05-13 15:54 267 查看
其它

编号类别ORACLEMYSQL注释
1内连接的更改1、

select a.*, b.*, c.*, d.*

from a, b, c, d

where a.id = b.id

and a.name is not null

and a.id = c.id(+)

and a.id = d.id(+)

"(+)"所在位置的另一侧为连接的方向，

所以上面的例子1是左连接。

以下的例子2既是右连接。

2、

select a.*, b.*, c.*, d.*

from a, b, c, d

where a.id = b.id

and a.name is not null

and a.id(+) = c.id

方法一

select a.*, c.*, d.*

from a

left join(c, d)

on (a.id = c.id and a.id = d.id), b

where a.id = b.id

and a.name is not null

方法二

select a.*, c.*, d.*

from a

left join c on a.id = c.id

left join d on a.id = d.id, b

where a.id = b.id

and a.name is not null		oracle sql语句和mysql sql语句有一定的区别.

1. oracle左连接,右连接可以使用(+)来实现.

Mysql只能使用left join ,right join等关键字.
2最后一句执行的sql statement所取得或

影响的条数		SQL%ROWCOUNT执行select语句后用: FOUND_ROWS()

执行update delete insert语句后用:

ROW_COUNT(). 		oracle中:

sql 表示最后一句执行的 SQL Statement, rowcount表示該 SQL 所取得或影响的条数.

Mysql中:

执行select语句后查询所影响的条数用: FOUND_ROWS()

执行update delete insert语句后查询所影响的条数用: ROW_COUNT()
3查询分页SELECT t1.*

FROM

(SELECT MSG_INT_KEY,

MSG_TY,

MSG_CD,

ROWNUM ROW_NUM

FROM SD_SYS_MSG

WHERE (ii_msg_int_key IS NULL

OR msg_int_key = ii_msg_int_key)

ORDER BY MSG_CD

) t1

WHERE (in_page_no IS NULL)

OR (t1.ROW_NUM >

((in_page_no -1)*li_per_page_amt)

AND t1.ROW_NUM <

(in_page_no*li_per_page_amt + 1)

);		方法:使用循环变量替换oracle中ROWNUM

set @mycnt = 0;

SELECT (@mycnt := @mycnt + 1) as ROW_NUM,t1.*

FROM

(SELECT MSG_INT_KEY, MSG_TY, MSG_CD, ROWNUM ROW_NUM

FROM SD_SYS_MSG

WHERE (ii_msg_int_key IS NULL OR msg_int_key = ii_msg_int_key )

ORDER BY MSG_CD

) t1

WHERE (in_page_no IS NULL)

OR (t1.ROW_NUM> ((in_page_no - 1) * li_per_page_amt)

AND t1.ROW_NUM < (in_page_no * li_per_page_amt + 1)

);
4java null值""作为参数传入后,在oracle中将识别为null""作为参数据传mysql还是""现在java代码需要修改:

inPara.add(MSG_TY.equals("") ? null : MSG_TY);
5执行动态sqllv_sql := 'SELECT ' ||' distinct ' || iv_cd_field_name || ' FIELD1 '||

' FROM ' || iv_table_name ||

' WHERE ' || NVL(iv_where_cause,' 1=1 ');

OPEN l_sys_cur FOR lv_sql;		set @a = iv_cd_field_name;

set @b = iv_table_name;

set @c = IFNULL(iv_where_cause,' 1=1 ');

SET @s = concat('SELECT distinct ', @a , ' FIELD1 FROM ' , @b ,

' WHERE ' , IFNULL(@c,' 1=1 '));

PREPARE stmt3 FROM @s;

EXECUTE stmt3;

DEALLOCATE PREPARE stmt3;		1. oracle可以将动态sql放在游标中执行.

mysql游标声明有一定的局限性: mysql游标必须在声明处理程序之前被声明，并且变量和条件必须在声明光标或处理程序之前被声明。Mysql采用Prepared Statements实现动态sql. 例子如下:

INT Emp_id_var = 56

PREPARE SQLSA

FROM "DELETE FROM employee WHERE emp_id=?" ;

EXECUTE SQLSA USING :Emp_id_var ;

6存储过程相互调用时传递数组oracle使用数组步骤:

1. 将传入的字符串通过P_UNPACK_LIST方法转换为数组.(lo_holiday_jan_upl即为数组)

P_UNPACK_LIST(iv_jan__str, lv_delimiter, lo_holiday_jan_upl);

2. 传数组到另一个存储过程.

P_MOD_MONTH(iv_year, 1, lo_holiday_jan_upl, iv_user_cd);

3. P_MOD_MONTH中使用数组: (将数组中的各个元素取出来插入到SD_HOLIDAY表)

FOR li_cnt IN 0 .. 9 LOOP

IF iv_daystr(li_cnt) IS NOT NULL THEN

INSERT INTO SD_HOLIDAY

(HOLIDAY_INT_KEY,

YEAR,

MONTH,

DAY,

ENABLE_FLAG,

CREATE_BY,

CREATE_DATE,

LAST_UPD_BY,

LAST_UPD_DATE)

VALUES

(SEQ_HOLIDAY_INT_KEY.NEXTVAL,

iv_year,

iv_month,

iv_daystr(li_cnt),

1,

iv_user_cd,

ld_sys_date,

iv_user_cd,

ld_sys_date);

END IF;

END LOOP;

mysql中数用数组步骤:

1. 将需要处理的字符串交给执行业务逻辑

的存储过程处理.

CALL SD_HOLIDAY_P_MOD_MONTH(iv_year, 1, iv_jan__str, iv_user_cd);

2. SD_HOLIDAY_P_MOD_MONTH中处理字符串. (将字符串按自定格式分隔出来,在对每个小字符串进行业务逻辑处理.)

SET lv_inputstr = iv_inputstr;

loopLable:LOOP

IF li_cnt > 9 THEN

LEAVE looplable;

ELSE

SET li_pos = INSTR(lv_inputstr, iv_delimiter);

IF li_pos = 0 THEN

leave looplable;

ELSE

set temp_str = SUBSTR(lv_inputstr, 1, li_pos - 1);

/*插入temp_str到SD_HOLIDAY表*/

INSERT INTO SD_HOLIDAY(...)

SET lv_inputstr = SUBSTRING(lv_inputstr, li_pos + LENGTH(iv_delimiter));

END IF;

SET li_cnt = li_cnt+1;

END IF;

END LOOP loopLable;		存储过程相互调用时传递数组解决方法:

oracle中传入12个字符串到存储过程,然后将这12个字符串转换为12个数组,再调用其他存储过程并将这12个数组分别传给存储过程,便利每个数组进行业务逻辑处理.

mysql解决方法: 将存储过程中的数组去掉,两个存储过程调用时直接传递字符串,然后再需要处理业务逻辑的地方将字符串分解,进行业务逻辑处理.

可以参考<<2009002-OTMPPS-Difficult Questions-0001.doc>> 中 2.4.2 逐层分解字符串
7Java无法以String来接取intselect fac_unit_key FILED1
在oracle可以		select fac_unit_key FILED1
在mysql中要改

select CAST(fac_unit_key AS CHAR) FILED1		CAST(intvalue AS CHAR)
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