cusor的使用以及函数的创建和存储过程

cursor的使用

        declare  CURSOR  cusor is select * from table_表名;
empInfo  emp%ROWTYPE;
begin
open  cursor  ;//打开游标
fetch  cursor  into  empInfo;---使游标向下一行
---判断此行是否有数据被发现
while(cursor%FOUND) LOOP
操作
fetch  cusor  into empInfo;//修改游标，继续向下
end loop;
end;

 二:
        declare cursor cusor is select  from table_表名;
empInfo  emp%ROWTYPE;
begin 
for empInfo in cursor loop
操作
end loop;  
end;
---------------------------------函数function的创建---------------
ALTER FUNCTION [dbo].[GET_SPECIAL_NAME]
    (
      @SPECIALTY_ID INT
    )
RETURNS NVARCHAR(50)
 AS 
        BEGIN

DECLARE @DATA_COUNT INT;
            DECLARE @SPECIAL_NAME NVARCHAR(50) ;
            
SET @DATA_COUNT=(
SELECT 
COUNT(1) AS DATA_COUNT 
FROM 
PS_EXPERT_SPECIALTY PES 
WHERE 
PES.SPECIALTY_ID = @SPECIALTY_ID
AND PES.PARENT_ID IS NULL);

IF @DATA_COUNT > 0
SET @SPECIAL_NAME=(
SELECT 
PES.SPECIALTY_NAME 
FROM 
PS_EXPERT_SPECIALTY PES 
WHERE 
PES.SPECIALTY_ID = @SPECIALTY_ID
AND PES.PARENT_ID IS NULL);
ELSE
SET @SPECIAL_NAME=(
SELECT 
PES.SPECIALTY_NAME 
FROM 
PS_EXPERT_SPECIALTY PES,
PS_EXPERT_SPECIALTY PES2 
WHERE 
PES.SPECIALTY_ID = PES2.PARENT_ID