Linux C language Mysql operations and Character Set settings

Linux C language Mysql operations and Character Set settings
I. C language Mysql operations first install the libmysql library.
# Sudo apt-get install libmysql ++-dev: copy the MySQL database to the public database.
# Sudo cp-ri/usr/lib/mysql/*/usr/lib/configure the MySQL library.
# Mysql_config -- cflags -- libs 2. Create a database and a table

Start the terminal and enter the following command to enter mysql.
# Mysql-u username-p

Create a database.
Mysql> create database TemWet;

Create a data table monitZ tables? Http://www.bkjia.com/kf/ware/vc/ "target =" _ blank "class =" keylink "> vcixzZW5zZXJzo6yyorLlyOuy4srUyv2 + 3aGjPC9wPgoKCjxwcmUgY2xhc3M9" brush: SQL; ">Mysql> use TemWetDatabase changedmysql> create table monitor-> (-> Id int not null,-> monitor_name varchar (50),-> monitor_com varchar (50 ), -> primary key (Id)->); Query OK, 0 rows affected (0.10 sec)C program testing

Example code of c connection operation database:

# Include <mysql/mysql. h> # include <stdio. h> # include <stdlib. h> # include <string. h> static char * server_groups [] = {"embedded", "server", "this_program_server", (char *) NULL}; int main () {MYSQL mysql; MYSQL_RES * res; MYSQL_ROW row; char sqlcmd [200]; int t, r; mysql_init (& mysql); // initialize the MYSQL identifier for connecting to if (! Mysql_real_connect (& mysql, "localhost", "root", "root", "sensers", 0, NULL, 0) {fprintf (stderr, "unable to connect to the database, error cause: % s/n ", mysql_error (& mysql);} else {puts (" database connection successful "); // insert a record to the database first // sprintf (sqlcmd, "% s", "insert into friends (name, telephone) Values ('XX', 'xx ') "); // mysql_query (& mysql, sqlcmd); sprintf (sqlcmd," % s "," set names utf8; "); t = mysql_real_query (& mysql, sqlcmd, (unsigned int) strlen (sqlcmd); sprintf (sqlcmd, "% s", "select * from senser;"); t = mysql_real_query (& mysql, sqlcmd, (unsigned int) strlen (sqlcmd); if (t) {printf ("failed to query database % s/n", mysql_error (& mysql ));} else {res = mysql_store_result (& mysql); // return all query result sets while (row = mysql_fetch_row (res )) {// mysql_fetch_row obtain the next row of the result set for (t = 0; t <mysql_num_fields (res); t ++) {// Number of result set columns printf ("% s \ t", row [t]);} printf ("\ n "); int wet = atoi (row [2]); printf ("% d \ n", wet);} mysql_free_result (res); // The operation is complete, query Result set} mysql_close (& mysql); // closes the database connection} mysql_library_end (); // closes the MySQL database return EXIT_SUCCESS ;}

Compile the c file:
# Gcc sqltest. c-o sqltest-lmysqlclient

Compiled successfully and executed successfully.


Iv. Character Set settings

A piece of data with Chinese characters is inserted, but Chinese characters are garbled. This should be the character encoding problem of the database.

Solution:
Modify the MySQL configuration file/etc/mysql/my. cnf

Save and restart the mysql service.
View the character set of the database: mysql> show variables like "character_set _ % ';

Delete the previous database data table, create a new data table, and insert the data. It supports Chinese characters perfectly.