There is a multi-dimensional array, which can be customized. Suppose we want to find a key in this array for me:
Traverse multi-dimensional arrays and create an index for all keys to generate a one-dimensional array;
Check the upper-level array and data of the key by using the key name each time.
OK. the code is as follows:
IndexKey:
The code is as follows:
/*
Php multi-dimensional array quickly queries the parent key and parent key value based on the key name
/**
* FILE_NAME: arr. php FILE_PATH: test/
* Quick query of the parent key and parent key value based on the
I think so:
Iterate through multidimensional arrays and create a one-dimensional array by indexing all the keys;
Each time through the key name to check the parent array and data
OK, the code is as follows
Indexkey Creating an indexed array function:
Copy CodeThe code is as follows:
/**
* FILE_NAME:arr.php file_path:test/
* Quickly query the parent key and the parent
I think so:
Traverse multi-dimensional arrays and create an index for all keys to generate a one-dimensional array;
Check the upper-level array and data of the key by using the key name each time.
OK. The Code is as follows:
IndexKey:
Copy codeThe Code is as follows: /**
* FILE_NAME: arr. php FILE_PATH: test/
* Quick query of the parent key and parent
Tags: des io ar using for SP strong data onone, key and primary key differenceCREATE TABLE Wh_logrecord (logrecord_id Int (one) not NULL auto_increment,User_name varchar (+) default NULL,Operation_time datetime default NULL,Logrecord_operation varchar (+) default NULL,PRIMARY KEY (logrecord_id),KEY Wh_logrecord_user_na
In mysql, key, primary key, unique key and index are different, mysqlunique
Indexes in mysql are very important knowledge points. Compared with other knowledge points, indexes are more difficult to master, and there are many index types in mysql, such as primary key, unique key
one, key and primary key differenceint (one) not NULL auto_increment, user_name varchar (defaultDefault NULL, logrecord_operation varchar (defaultAnalytical:KEY Wh_logrecord_user_name (USER_NAME)The User_name field in this table establishes a foreign key with the Wh_logrecord_user_name table user_name fieldOutside the parentheses is the table that establishes th
What are the differences among KEY, primary key, unique key, and INDEX in MySQL? mysqlunique
You can split the questions raised in the questions to solve them step by step. In MySQL, KEY and INDEX are synonymous. This problem can be simplified to the difference between primary key
Tags: Describes res family implementation requires DOM field a bleTransferred from: http://zccst.iteye.com/blog/1697043 one, key and primary key difference CREATE TABLEWh_logrecord (logrecord_idint( One) not NULLAuto_increment,user_name varchar( -)default NULL, Operation_timedatetime default NULL, Logrecord_operationvarchar( -)default NULL,
PRIMARY KEY(logrecord
This article mainly introduces the specific definition and usefulness of super-key, candidate key, primary key, main attribute, foreign key in MySQL database. You can also refer to the topic.alibabacloud.com MySQL video tutorial and
MySQL manual。
First look at the definitions of the various keys:
Super
Key:I understand the public key + private key collectively.
Key pair:The Public key (certificate) and private key are in pairs.Each side of the communication holds its own private key and the other's public
Tags: copy create integrity Build blog can't ble update syncIf a field of one entity points to the primary key of another entity, it is called a foreign keyThe entity that is pointed to is called the primary entity (the primary table), also called the parent entity (the parent table).The entity that is responsible for pointing, called from the entity (from the table), also called the Child Entity (sub-table) Role:Used to constrain entities that are w
Key:I understand the public key + private key collectively.
Key pair:The Public key (certificate) and private key are in pairs. Each side of the communication holds its own private key and the other's public
SSH login provides two kinds of authentication methods: password (password) authentication method and key authentication method. where password (password) authentication method is one of our most commonly used, here is the key authentication method to log on to linux/Unix. Using key login is divided into 3 steps:1. Generate k
Super key: An attribute set that uniquely identifies a tuple in a relationship is called a hyper-key of a relational patternCandidate key (candidate Key): A super-key that does not contain extra attributes is called a candidate keyPrimary
SQL primary key constraints and foreign key constraints, SQL primary key constraintsPrimary key constraint SQL PRIMARY KEY constraint
The primary key constraint uniquely identifies each record in the database table.
The primary
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