How about high three nights?-JSON & amp; PHP, _ PHP Tutorial

How about high three nights?-JSON & amp; PHP ,. Hi, I went to eat hot pot last night. right, you didn't guess it was wrong. I just had a treat from my senior brother in Chengdu tonight. tomorrow I have a hot pot for friends, should I have been busy for three nights?-JSON & PHP,

Hi

I went to eat hot pot last night. Yes, you didn't guess it was wrong. I was in Chengdu.

There will be a treat for senior students tonight, and there will be a hot pot for friends tomorrow. Should the busy week have to be high for three consecutive nights (single graduate dogs are so easy to satisfy ). So I had to leave my business to write and write (not to write ...)

1. JSON

----- Introduction -----

Javascript Object Notation, a lightweight data exchange format

---

Basic syntax: Four Basic rules

The parallel data are separated by commas; the ING is represented by colons; the parallel data set (array) is represented by []; the ing set (object) is represented {}

For example, Beijing has an area of 16800 square kilometers and a resident population of 16 million people. Shanghai has an area of 6400 square kilometers and a resident population of 18 million people.

In JSON format:

[

{"City": "Beijing", "area": 16800, "population": 1600 },

{"City": "Shanghai", "area": 6400, "population": 1800}

]

---

Advantages: simple format, easy to read/write and transmit; support for multiple languages

Disadvantage: the character set must be Unicode; the syntax is too rigorous

2. PHP & MySQL

----- Php built-in mysql function (2 )-----

---- Four fetch functions _ fetch results

---

$ Query = mysqli_query ($ con, 'select * from test ');

Print_r (mysqli_fetch_row ($ query ));

The first fetch, mysql_fetch_row (), returns only the data of the first row;Note: In fact, it reads a row every time, row by row, So we can all come out like this:

$ Query = mysqli_query ($ con, 'select * from test ');
While ($ row = mysqli_fetch_row ($ query )){
Print_r ($ row );
}

In addition, if the number of calls exceeds the number of rows, no data exceeding the number of rows will be output, and null will be returned.

Array ([0] => 1 [1] => Tom) Array ([0] => 2 [1] => Tom) array ([0] => 3 [1] => Tom) Array ([0] => 4 [1] => Tom) array ([0] => 5 [1] => ???? ) Array ([0] => 6 [1] => Tom) Array ([0] => 7 [1] => ???? )

The returned result is an index array.

---

Mysql_fetch_array ()

$ Arr = mysqli_fetch_array ($ query );
Print_r ($ arr );

The usage is similar. result:

Array ([0] => 1 [id] => 1 [1] => Tom [name] => Tom)

Compare database data

Mysql> SELECT * from test;
+ ---- + ------ +
| Id | name |
+ ---- + ------ +
| 1 | Tom |
| 2 | Tom |
| 3 | Tom |
| 4 | Tom |
| 5 | ???? |
| 6 | Tom |
| 7 | ???? |
+ ---- + ------ +

Therefore, row generates an index array from a data record. by default, array retrieves a data record to generate an index array and an associated array.

Simply put, array can use the key name, which is quite convenient:

Echo $ arr ['name'];

However, the speed of array is a little slower.

At the same time, array also has the optional second parameter, which can be selected to output some arrays.

$ Arr = mysqli_fetch_array ($ query, MYSQL_ASSOC );
Print_r ($ arr );
Echo $ arr ['name'];

Get

Array ([id] => 1 [name] => Tom) Tom

MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH are three parameters.

---

Mysql_fetch_assoc ()

Basically, the output is the same as that in the previous section.

---

Mysql_fetch_object ()

An object is returned.

$ Obj = mysqli_fetch_object ($ query );
Echo $ obj-> name;

Echo"
";

Print_r ($ obj );

Result

Tom
StdClass Object ([id] => 1 [name] => Tom)

Similar to the row command, the output of a row can also be

Hi, I went to eat hot pot last night. Yes, you didn't guess it was wrong. I just had a treat from my senior brother in Chengdu tonight. I 'd like to have a hot pot tomorrow with friends...