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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)
); 　 4 java 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sql lv_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 7 Java无法以String来接取int select 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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