number of fields

Transfer from http://www.iteye.com/topic/2816111. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document

1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document corresponds to and corresponds to only an

1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document corresponds to and corresponds to only an

1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are a one-to-one relationship: the original documentShould and only correspond to one entity. In special

1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document corresponds to and corresponds to only an

This paper introduces 14 techniques in database design, which is summed up by many people in a large number of database analysis and design practice.The following 14 skills, is a lot of people in a large number of database analysis and design

and Ord (Mid (Version (), >51)) Explanation 1: Verify that Database version 51 is ASCII code 3 is correct >4.0 error is Explanation 2:ord () is a MySQL function used to get binary codes; Explanation 3:mid () is a function of

awk ProgrammingAwk is a programming language. Gawk, is the latest version, the current Linux version is used Gawkawk is a soft link to gawkhow awk works BEGIN #在未读取文件行之前执行Primary input loop, which executes repeatedly until the terminating condition

Shell script (vi)(2) awkA, awk programming mode#awk编程模式分三个阶段: Execute code Snippet before reading input file (identified by the BEGIN keyword)Execute code snippet after #读取输入文件时执行代码段, reading input file (identified by end keyword)B, pattern matching#

The serialization and deserialization of Java objects is also part of the Java Foundation, and some of the mechanisms and principles of Java serialization are described below.Java The analysis of serialization algorithmSerialization (serialization)

This article describes the most common tools for using the shell to process text under Linux:Find, grep, Xargs, Sort, uniq, tr, cut, paste, WC, sed, awk;The examples and parameters provided are the most commonly used and most practical.I use the

One of the school's external teachers wrote the program, book + Student management system, filename 001.php,002.php,003.php ... (b) problem out at 004.php number of lines I forgot, too. "> "width=" 136 "height=" 181 "> title: Pay attention to

This article describes the most common tools for using the shell to process text under Linux:Find, grep, Xargs, Sort, uniq, tr, cut, paste, WC, sed, awk;The examples and parameters provided are the most commonly used and most practical.I use the

Lucene Index file structureBasic concepts Indexing (Index) Lucene's index consists of a number of files, which are placed in the same directory Segment (segment) An index of Lucene consists of multiple

Analysis of Java serialization algorithm Serialization (serialization) is a process of describing an object in a sequence of bytes; Deserialization deserialization is the process of resetting these bytes into an object. The Java Serialization API

Each group of queries can get its result set, if the need to combine multiple query results into a result set, can be implemented by the set operation. such as union, and set, and do not remove duplicate rows (unoin all), intersections (INTERSECT),

The previous blog is mainly string type, list type and set type, below hash type and Zset type 1,hset Description: Sets the value of the field field in the hash table key to values. If key does not exist, a new hash table is created and Hset. If

hdel key field [field ...] Deletes one or more specified domains in the hash table key, and the nonexistent fields are ignored.In versions below Redis2.4, Hdel can delete only a single domain at a time, and if you need to delete multiple domains in

Database design principles (reproduced)1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document corresponds

1. Relationship between the original document and the entityCan be a pair of one or one-to-many, many-to-many relationships. In general, they are one-to-one relationships: a single original document corresponds to and corresponds to only an