I have not learned PHP before, just recently a project needs to use, I decided to learn while doing PHP.
1 in an SQL statement, you can add a restriction: Left (text,20) takes only the first 20 words of text;
2 can be used with limit FromRecord, recordnum to use as paging, such as the limit 0,30 indicates that the first record from the beginning of the traversal of 30 records;
32 Table connections can be: Table1 join table2 using X (x is a public field for two tables), or table1 join table2 on table1.x = table2.x
4 PHP Get querystring can be used $page = $_get[' page '];
Or
$page = $_request[' page '];
Where request can obtain post,get,querystring and other characters;
Before that, I saw a more stupid approach:
Parse_str ($_server[' query_string '), $output); First, the query string is stored in an array $output
$page = $output [' page ']; Then indexed by the variable name
5 The comparison of date functions in PHP is actually a comparison of strings;
6 MySQL Date type data can be: 2000-02-03,2002.02.03,2002.2.3,02.02.03,02.2.3, that is, must have a month and day, and must be '-' or '. ' Separated.
7 data () to get time there will be a timezone problem, I found that the time is less than 8 hours, because php.ini inside the default configuration is the GTM U.S. time zone;
WORKAROUND: You can modify the php.ini:
[Date]
; Defines the default timezone used by the date functions
Date.timezone = "Asia/shanghai"
or use the date () function to add Date_default_timezone_set ("PRC");
81 time, debugging in the body always said I lacked ")", a half-day is intval ($_post[' consumetype ')) problem, in the database this field is varchar (50), in the Zengsong table I do not use intval function, is because its ID is ... integers and char can be converted to each other, but in the other two tables is a5a,sp07-01, but how does it convert to int type?
Let's take a look at the declaration of the Intval function:
The Intval function is used to get the integer value of the variable: int intval (mixed var [, int base])
Returns the integer value of the variable var by using a specific binary conversion (by default, decimal).
var can be any scalar type. Intval () cannot be used with an array or object.
9 Another inexplicable problem, to user name 1 login can, change a ' Bo ' Landing, the system is inError: Said I ran the wrong time: Missing ")", Nnd. Checked, it turns out that the variable type in the SQL statement is inconsistent with the database.
In PHP, when converting from floating-point numbers to integers, the number is rounded (discarding decimal digits).
11 in the MySQL INSERT statement, if the self-increment field is to be used (NULL) instead.
PHP is garbled in Chinese??? Problem solving:
Add mysql_query after mysql_connect ("Set names ' gb2312 '");
Or use the UTF8 code, you do not have to join the above statement.
There are also function Iconv ("GBK", "UTF8", "string"), and various character encoding conversions can be implemented.
http://www.bkjia.com/PHPjc/632448.html www.bkjia.com true http://www.bkjia.com/PHPjc/632448.html techarticle I didn't learn PHP before, and I decided to learn to do PHP while I was working on a project. 1 in an SQL statement, you can add a constraint by adding: Left (text,20) takes only the first 20 words of text;
