Nisi’s work blog

Nisi’s work blog – programing tips

New Line in PHP

Printing a new line witch is visible in a web page is made like this:

  1. echo(‘line 1′.\n.‘line 2′);
  2.  

the code above will print line 1 on a line and line 2 on a new line.

Now if you have to generate a CSV file  <br/> wil not work  you have to use  \n like in C language but there is a trick.

  1. echo (‘line 1 \n line 2′); //will print something like    line 1 \n line 2
  2. echo("line 2 \n line 2")// will print line 1 on the first line and line 2 on the second line

double quotes will parse \n as a new line and single quotes will believe is is a text

Neural Networks in PHP

Browsing phpclasses.org I had found a very interesting article Neural Networks in PHP . For anyone who dont know yet “Neural networks allow emulating the behavior of a human brain in software applications.”

In this article you can read how to implement Neural Mesh to develop Neural Network applications in PHP. (Neural Networks in PHP)

Neural Mesh is an open source, pure PHP code based Neural Network manager and framework that makes it easier to work with Neural Networks.

Neural Mesh home page: http://neuralmesh.com/

  • Pure PHP & MySQl
  • Adaptive Learning
  • Implement in any enviroment
  • Web Api
  • Fast

Restore MySql database using command line

mysql -u USER -p DBNAME < dump.sql

Where:

  • USER is your username
  • DBNAME is Databas witch will be restored
  • dump.sql (any .sql file can be used) is your database dump

Format PHP Date to MySQL Format


When you insert or update a date in a mysql Table you have to remember that Mysql have 3 types of date

  • DATETIME         ( default format 0000-00-00 00:00:00 )
  • DATE                ( default format 0000-00-00 )
  • TIMESTAMP      ( default format 0000-00-00 00:00:00 )

PHP code:

  1.       DATE ->  $mysqldate = date( ‘Y-m-d’ );
  2.       DATETIME, TSTAMP  -> $mysqldate = date( ‘Y-m-d H:i:s’);

Now maybe you have have read some date field from MySql table and want to convert it to PHP date

  • $phpdate = strtotime( $mysqldate );

MySQL variables range


TINYINT
A very small integer
The signed range is –128 to 127. The unsigned range is 0 to 255.

SMALLINT
A small integer
The signed range is –32768 to 32767. The unsigned range is 0 to 65535

MEDIUMINT
A medium-size integer
The signed range is –8388608 to 8388607. The unsigned range is 0 to 16777215

INT or INTEGER
A normal-size integer
The signed range is –2147483648 to 2147483647. The unsigned range is 0 to 4294967295

BIGINT
A large integer
The signed range is –9223372036854775808 to 9223372036854775807. The unsigned range is 0 to 18446744073709551615

FLOAT
A small (single-precision) floating-point number. Cannot be unsigned
Ranges are –3.402823466E+38 to –1.175494351E-38, 0 and 1.175494351E-38 to 3.402823466E+38. If the number of Decimals is not set or <= 24 it is a single-precision floating point number

DOUBLE,
DOUBLE PRECISION,
REAL
A normal-size (double-precision) floating-point number. Cannot be unsigned
Ranges are -1.7976931348623157E+308 to -2.2250738585072014E-308, 0 and 2.2250738585072014E-308 to 1.7976931348623157E+308. If the number of Decimals is not set or 25 <= Decimals <= 53 stands for a double-precision floating point number

DECIMAL,
NUMERIC
An unpacked floating-point number. Cannot be unsigned
Behaves like a CHAR column: “unpacked” means the number is stored as a string, using one character for each digit of the value. The decimal point, and, for negative numbers, the ‘-‘ sign is not counted in Length. If Decimals is 0, values will have no decimal point or fractional part. The maximum range of DECIMAL values is the same as for DOUBLE, but the actual range for a given DECIMAL column may be constrained by the choice of Length and Decimals. If Decimals is left out it’s set to 0. If Length is left out it’s set to 10. Note that in MySQL 3.22 the Length includes the sign and the decimal point

DATE
A date
The supported range is ‘1000-01-01’ to ‘9999-12-31’. MySQL displays DATE values in ‘YYYY-MM-DD’ format

DATETIME
A date and time combination
The supported range is ‘1000-01-01 00:00:00’ to ‘9999-12-31 23:59:59’. MySQL displays DATETIME values in ‘YYYY-MM-DD HH:MM:SS’ format

TIMESTAMP
A timestamp
The range is ‘1970-01-01 00:00:00’ to sometime in the year 2037. MySQL displays TIMESTAMP values in YYYYMMDDHHMMSS, YYMMDDHHMMSS, YYYYMMDD or YYMMDD format, depending on whether M is 14 (or missing), 12, 8 or 6, but allows you to assign values to TIMESTAMP columns using either strings or numbers. A TIMESTAMP column is useful for recording the date and time of an INSERT or UPDATE operation because it is automatically set to the date and time of the most recent operation if you don’t give it a value yourself

TIME
A time
The range is ‘-838:59:59’ to ‘838:59:59’. MySQL displays TIME values in ‘HH:MM:SS’ format, but allows you to assign values to TIME columns using either strings or numbers

YEAR
A year in 2- or 4- digit formats (default is 4-digit)
The allowable values are 1901 to 2155, and 0000 in the 4 year format and 1970-2069 if you use the 2 digit format (70-69). MySQL displays YEAR values in YYYY format, but allows you to assign values to YEAR columns using either strings or numbers. (The YEAR type is new in MySQL 3.22.)

CHAR
A fixed-length string that is always right-padded with spaces to the specified length when stored
The range of Length is 1 to 255 characters. Trailing spaces are removed when the value is retrieved. CHAR values are sorted and compared in case-insensitive fashion according to the default character set unless the BINARY keyword is given

VARCHAR
A variable-length string. Note: Trailing spaces are removed when the value is stored (this differs from the ANSI SQL specification)
The range of Length is 1 to 255 characters. VARCHAR values are sorted and compared in case-insensitive fashion unless the BINARY keyword is given

TINYBLOB,
TINYTEXT

A BLOB or TEXT column with a maximum length of 255 (2^8 – 1) characters

BLOB,
TEXT

A BLOB or TEXT column with a maximum length of 65535 (2^16 – 1) characters

MEDIUMBLOB,
MEDIUMTEXT

A BLOB or TEXT column with a maximum length of 16777215 (2^24 – 1) characters

LONGBLOB,
LONGTEXT

A BLOB or TEXT column with a maximum length of 4294967295 (2^32 – 1) characters

ENUM
An enumeration
A string object that can have only one value, chosen from the list of values ‘value1’, ‘value2’, …, or NULL. An ENUM can have a maximum of 65535 distinct values.

SET
A set
A string object that can have zero or more values, each of which must be chosen from the list of values ‘value1’, ‘value2’, … A SET can have a maximum of 64 members