SQL基础：通过T-SQL语句创建游标与实现数据库加解密功能

–赋值
set @TableName=’Student’;
SET @FieldName=’Name’;
SET @PrimaryKey=’Id’;
–创建动态游标
set @sql = ‘declare rowCursor cursor For select ‘+@PrimaryKey+’ as PKey , ‘+@FieldName
+’ as DbValue from ‘+@TableName;
EXEC(@sql);
–打开游标
OPEN rowCursor;
–取值
fetch next from rowCursor into @PKey,@DbValue;
–循环
while(@@FETCH_STATUS=0)
begin
declare @ExecSql varchar(100);
set @ExecSql=’Update ‘+@TableName +’ set ‘+@FieldName+’ = 234324324′;
PRINT @ExecSql
EXEC(@ExecSql)
fetch next from rowCursor into @PKey,@DbValue;
end
–关闭游标
close rowCursor;
–释放游标控件
deallocate rowCursor;

–加密
DECLARE @Pwd nvarchar(max)
SET @Pwd=’测试加密’
–将varbinary类型转换成varchar类型
INSERT INTO Users VALUES (‘admin’,sys.fn_varbintohexstr(ENCRYPTBYPASSPHRASE(‘32423sd’,@Pwd)))

SELECT * FROM Users

DECLARE @pv varbinary(max)
DECLARE @str nvarchar(max)
DECLARE @sql nvarchar(max)
–将varchar类型转换成varbinary类型
SELECT @str=’0x0100000079e98bc2209c61038f9fc2eaaba24d6b8daad08fd98a41b6′
set @sql=N’set @p=’+@str+N’;’
exec sp_executesql @sql,
N’@p as varbinary(max) output’,
@p=@pv output
PRINT @pv
–解密
SELECT CONVERT(VARCHAR(MAX), DecryptByPassPhrase(‘123ASSDSS’,@pv))
GO