bigint

就用数据数据库表地址数据（中国地区） 来说吧（用Windows 请使用 gbk ！！） 可直接运行（去除注解） 存储过程： DELIMITER // drop procedure if exists findLChild // /* iid 递归父节点 ， layer 允许递归深度 */ CREATE PROCEDURE findLChild(iid bigint ( 20 ),layer bigint ( 20 )) BEGIN /* 创建接受查询的临时表 */ create temporary table if not exists tmp_table(id bigint ( 20 ),name varchar ( 50 )) ENGINE = InnoDB DEFAULT CHARSET = utf8; /* 最高允许递归数 */ SET @@max_sp_recursion_depth = 99 ; call iterative(iid,layer); /* 核心数据收集 */ select * from tmp_table ; /* 展现 */ drop temporary table if exists tmp_table ; /* 删除临时表 */ END ; // DELIMITER ; DELIMITER // drop procedure if exists

I'm using a 128 bit integer counter in the very inner loops of my C++ code. (Irrelevant background: The actual application is evaluating finite difference equations on a regular grid, which involves repetitively incrementing large integers, and even 64 bits isn't enough precision because small rounding accumulates enough to affect the answers.) I've represented the integer as two 64 bit unsigned longs. I now need to increment those values by a 128 bit constant. This isn't hard, but you have to manually catch the carry from the low word to the high word. I have working code something like this:

I want a 128 bit integer because I want to store results of multiplication of two 64 bit numbers. Is there any such thing in gcc 4.4 and above? A 128-bit integer type is only ever available on 64-bit targets , so you need to check for availability even if you have already detected a recent GCC version. In theory gcc could support TImode integers on machines where it would take 4x 32-bit registers to hold one, but I don't think there are any cases where it does. GCC 4.6 and later has a __int128 / unsigned __int128 defined as a built-in type. Use #ifdef __SIZEOF_INT128__ to detect it. GCC 4.1

一、CharIndex 1：CharIndex语法： CharIndex（expression1,expression2[,start_location]） 2:参数 expression1 一个表达式,其中包含要查找的字符的序列。expression1是一个字符串数据类别的表达式。 expression2 一个表达式，通常是一个为指定序列搜索的列。expression2属于字符串数据类别. start_location 开始在expression2中搜索expression1时的字符位置。如果start_location未被指定、是一个负数或零，则将从espression2的开头开始搜索。start_location可以是bigint类型。 3:返回类型 如果expression2的数据类型为varchar(max),nvarchar(max)或varbinnary(max),则为bigint，否则为int。 4：备注 如果在expression2内找不到expression1,则charindex返回0. charindex将根据输入的排序规则执行比较操作。若要以指定排序规则进行比较，则可以使用collate将显式排序规则应用于输入值。 返回的开始位置从1开始，而非从0开始。 5：例子 select charindex('A','BADF',1) ： 2 select

I am trying to calculate 100! I am looking for the simplest way to accomplish this using C. I have read around but have not found a concrete answer. If you must know, I program in Xcode in Mac os X. Thanks! If you're looking for a simple library, libtommath (from libtomcrypt) is probably what you want. If you're looking to write a simple implementation yourself (either as a learning exercise or because you only need a very limited subset of bigint functionality and don't want to tack on a dependency to a large library, namespace pollution, etc.), then I might suggest the following for your