substring | 易学教程

数据库误删了数据再也不用跑路了，

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USE master GO --创建数据库 CREATE DATABASE test GO USE [test] GO --创建表 CREATE TABLE [dbo].[aa]( [id] [int] IDENTITY(1,1) NOT NULL, [NAME] [nvarchar](200) NULL ) ON [PRIMARY] GO --插入测试数据 INSERT [dbo].[aa] ( [NAME] ) SELECT '你好' GO --删除数据 Delete from aa Go --验证数据是否已经删除 Select * from aa Go 上面是创建数据库，表，添加数据，删除数据下面写存储过程； --------------------------开始存储过程----------------------------------------- CREATE PROCEDURE Recover_Deleted_Data_Proc @Database_Name NVARCHAR(MAX) , @SchemaName_n_TableName NVARCHAR(MAX) , @Date_From DATETIME = '1900/01/01' , @Date_To DATETIME = '9999/12/31' AS DECLARE @RowLogContents

Extracting substring from string based on delimiter

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问题 I am trying to extract the data out of an encoded 2D barcode. The extraction part is working fine, and I can get the value in a text input. E.g., the decoded string is ]d2 01 05000456013482 17 201200 10 00001/: 21 0000000001 Based on the following rules (couldn't get the proper table markdown thus attaching a picture), I am trying to extract the substrings from the string mentioned above. Substrings I want to extract: 05000456013482 (which is after the delimiter 01) 201200 (which is after

3. Longest Substring Without Repeating Characters -- SlidingWindow

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3. Longest Substring Without Repeating Characters Given a string, find the length of the longest substring without repeating characters. Example 1: Input: "abcabcbb" Output: 3 Explanation: The answer is "abc", with the length of 3. Example 2: Input: "bbbbb" Output: 1 Explanation: The answer is "b", with the length of 1. Example 3: Input: "pwwkew" Output: 3 Explanation: The answer is "wke", with the length of 3. Note that the answer must be a substring , "pwke" is a subsequence and not a substring. 双指针，滑动窗口 class Solution: def lengthOfLongestSubstring(self, s: str) -> int: if not s: return 0

高级bash编程指南（三）

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该章从第九章变量访问开始一.内部变量 1.内建变量 $FUNCNAME，当前函数的名字 func() { echo "$FUNCNAME" #func } 2.$IFS内部字段分割符当shell读取输入时，它给出来分割单词的一组字符，它通常是空格，制表符和换行符。 $* 所有的参数用环境变量$IFS的第一个字符分割开 $@则不是用$IFS中的字符分割变量。 3.$LINENO表示在脚本中该变量出现时的所在的行数 4.$SECONDS脚本已运行的秒数，sleep num ，程序停止num秒 5.$TMOUT，经错$TMOUT后，shell提示符会超时，这将使此shell退出登录 6.在使用$*时一定要用引号引起，否则在某一些情况下会出错　　$!在后台运行的最后一个作业的PID 　　$_保存迁移个命令最后一个参数的变量值　　$?一个命令，函数或脚本自身的退出码　　$$脚本本身的PID 二.操作字符串 1.字符串长度　　${#string},expr length $string,expr "$string" : ‘.*’（单引号）　　2.匹配字符串开头的字串的长度　　expr match "$string" '$substring'　　　　expr "$string" : '$substring'　　#substring is Resular Expressions

printing out 1 random letter of a word php functions [duplicate]

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问题 This question already has answers here : a method of selecting random characters from given string (15 answers) Closed 5 years ago . i want to Use strlen(), substr(), and rand() to print a random character from my name to the screen. <html> <p> <?php // Use strlen(), substr(), and rand() to // print a random character from my name to the screen. $name = "jordi"; $length = strlen("$name"); $length = rand(); $partial = substr($lengt, 0,5); print $name. "<br />"; print $length. "<br />"; print

How to convert comma-delimited file to pipe-delimited in vb.net

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问题 There are lots of search results on the web (and in SO) for something similar to what I need to do, but I haven't run into a solution yet for my particular situation. I have a comma-delimited file in which only columns that have commas within them have double quotes around them. Other fields that have no comma in them are simply separated by the comma. Take this example: 123,"box,toy",phone,"red,car,cat,dog","bike,pencil",man,africa,yellow,"jump,rope" The output for that line needs to be: 123

459. Repeated Substring Pattern

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459. Repeated Substring Pattern Easy Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000. Example 1: Input: "abab" Output: True Explanation: It's the substring "ab" twice. Example 2: Input: "aba" Output: False Example 3: Input: "abcabcabcabc" Output: True Explanation: It's the substring "abc" four times. (And the substring "abcabc" twice.) 这道题的题意是让我们判断一个字符串是否能拆成多个子串，既然能拆成多个子串

Remove a character from a given position on Oracle

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问题 Is there anyway to remove a character from a given position? Let's say my word is: PANCAKES And I want to remove the 2nd letter (in this case, 'A'), so i want PNCAKES as my return. Translate doesnt work for this. Replace doesnt work for this. Regex is damn complicated... Ideas? 回答1: Example: SUBSTR('PANCAKES', 0, INSTR('PANCAKES', 'A', 1, 1)-1) || SUBSTR('PANCAKES', INSTR('PANCAKES', 'A', 1, 1)+1) I don't have an Oracle instance to test with, might have to tweak the -1/+1 to get the position

remove first two characters for all column names in a data frame in R

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问题 Is there a way to remove character strings by position from all column names in a data frame for eg if i have column names like: ab_sales1 kj_sales2 lm_sales3 .....pk_sales100 10 34 64 ..... 288 I would like my output column names to be something like sales1 sales2 sales3 .....sales100 10 34 64 .... 288 I know string functions can be used on rows but I could not find something for column names 回答1: Use substring() df <- data.frame(ab_sales1 = rnorm(6), kj_sales2 = rnorm(6), lm_sales3 = rnorm

Is there a method like JavaScript's substr in Rust?

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问题 I looked at the Rust docs for String but I can't find a way to extract a substring. Is there a method like JavaScript's substr in Rust? If not, how would you implement it? str.substr(start[, length]) The closest is probably slice_unchecked but it uses byte offsets instead of character indexes and is marked unsafe . 回答1: For characters, you can use s.chars().skip(pos).take(len) : fn main() { let s = "Hello, world!"; let ss: String = s.chars().skip(7).take(5).collect(); println!("{}", ss); }