Erlang connects to the MySQL database

Reprinted: http://www.iteye.com/topic/910030

 

Erlang connects to the MySQL database

 

 

1. Driver download and Installation

 

1. Download Erlang-mysql-driver

As follows:

SVN checkout http://erlang-mysql-driver.googlecode.com/svn/trunk/ MySQL

 (If you have not installed SVN, the attachment provides the source code for download)

2. compile all source codes under SRC

ERlC *. erl

 

3. Create Ebin under MySQL and copy all *. Beam under SRC to Ebin.

4. Copy the entire MySQL folder to Erlang/lib.

 

Ii. Database Operations

1Connect to MySQL:

MySQL: start_link (poolid, "localhost", "root", "password", "databasename ").

 

2 MYSQL: connect (poolid, host ,? Port, user, password, database, undefined,

Reconnect ).% Establish a connection

 

3Data Operations

Add:

MySQL: Fetch (poolid, <"insert into…"> ).

Query:

MySQL: Fetch (P1, <"select * from user"> ).

 

4. What should I do after receiving the data?

Fetch (poolid, "select * from user")-> result

% Result = {data, mysqlres} | {updated, mysqlres} |

% {Error, mysqlres}

 

NQuery: {Data, mysqlres} = fetch (poolid, <"select * from user"> ).

Obtain field name information:

Fieldinfo = MYSQL: get_result_field_info (mysqlres ).

Obtain the field value:

Allrows = MYSQL: get_result_rows (mysqlres)

NUpdate:

{Updated, UD }= MYSQL: Fetch (poolid, <"Update * from user"> ).

Affectedrow = MYSQL: get_result_affected_rows (UD). % get the number of affected records

 

NError

{Error, err }= fetch (poolid, <"Update * from user"> ).

Reason = MYSQL: get_result_reason (mysqlres). % error cause

Note: encoding, the eighth parameter of MySQL: start_link, is set to utf8 to support Chinese characters.