參考資料：http://dev.mysql.com/doc/refman/5.5/en/c.html
近幾天，工作中需要用到MYSQL數據庫編程，開始學習linux下mysql c編程。剛把一個程序寫得七七八八，寫一下總結。
這幾天看得最多的，就是MYSQL的官方文檔了，一邊看文檔，一邊寫程序試着使用裏面提到的接口，熟悉起來還算是比較快的。
先說說編程環境吧，操作系統：linux,編譯軟件：g++，庫文件：mysql-connector-c-6.0.2-linux-glibc2.3-x86-64bit
1.下載安裝庫文件。因爲開發的機子中沒有安裝mysql，系統沒有mysql編程需要用到的庫文件，只能自己下載，
在官網http://dev.mysql.com/downloads/connector/c/#downloads找到這個庫文件，下載，解壓，放到系統特定目錄（自己隨便放，知道路徑就行了）。
2.編寫程序。
3.進行編譯。寫完測試程序後，執行，g++ dminingmysql.cpp _public.cpp -o dminingmysql -I(mysql庫文件存放路徑/include) -L(mysql庫文件存放目錄/lib) -lmysqlclient -lz。
就可以運行查看結果了。
基本數據結構：
MYSQL：數據庫連接句柄，不能COPY，只能使用mysql_init()獲得
MYSQL_RES：用來保存結果集（result set）
MYSQL_FIELD：查看字段屬性（字段名，長度，字段類型......）
基本方法：
MYSQL *mysql_init(MYSQL *mysql)：MYSQL數據結構使用前要使用該方法進行初始化。
Description
Allocates or initializes a MYSQL object suitable for mysql_real_connect(). If mysql is a NULL pointer, the function allocates, initializes, and returns a new object. Otherwise, the object is initialized and the address of the object is returned. If mysql_init() allocates a new object, it is freed when mysql_close() is called to close the connection.
Return Values
An initialized MYSQL* handle. NULL if there was insufficient memory to allocate a new object.
Errors
In case of insufficient memory, NULL is returned.
MYSQL *mysql_real_connect(MYSQL *mysql, const char *host, const char *user, const char *passwd, const char *db, unsigned int port, const char *unix_socket, unsigned long client_flag)：初始完MYSQL後，建立連接。
Description
mysql_real_connect() attempts to establish a connection to a MySQL database engine running on host.mysql_real_connect() must complete successfully before you can execute any other API functions that require a valid MYSQL connection handle structure.The first parameter should be the address of an existing MYSQL structure. Before calling mysql_real_connect()you must call mysql_init() to initialize the MYSQL structure.
Return Values
A MYSQL* connection handle if the connection was successful, NULL if the connection was unsuccessful. For a successful connection, the return value is the same as the value of the first parameter.
unsigned long mysql_get_server_version(MYSQL *mysql)：獲取服務器版本
Description
Returns the version number of the server as an integer.
Return Values
A number that represents the MySQL server version in this format:
major_version*10000 + minor_version *100 + sub_version
For example, 5.1.5 is returned as 50105.
This function is useful in client programs for quickly determining whether some version-specific server capability exists.
Errors
None.
MYSQL_RES *mysql_list_dbs(MYSQL *mysql, const char *wild)：列出服務器的數據庫
Description
Returns a result set consisting of database names on the server that match the simple regular expression specified by the wild parameter. wild may contain the wildcard characters “%” or “_”, or may be a NULL pointer to match all databases. Calling mysql_list_dbs() is similar to executing the query SHOW DATABASES [LIKE.wild]
You must free the result set with mysql_free_result().
Return Values
A MYSQL_RES result set for success. NULL if an error occurred.
MYSQL_FIELD *mysql_fetch_fields(MYSQL_RES *result)：獲取查詢的字段信息（長度，字段名，字段類型等等）
Description
Returns an array of all MYSQL_FIELD structures for a result set. Each structure provides the field definition for one column of the result set.
Return Values
An array of MYSQL_FIELD structures for all columns of a result set.
Errors
None.
MYSQL_ROW mysql_fetch_row(MYSQL_RES *result)：根據結果集獲得一行記錄信息。
Description
Retrieves the next row of a result set.
int mysql_query(MYSQL *mysql, const char *stmt_str)：執行SQL語句
Description
Executes the SQL statement pointed to by the null-terminated string stmt_str. Normally, the string must consist of a single SQL statement and you should not add a terminating semicolon (“;”) or /g to the statement. If multiple-statement execution has been enabled, the string can contain several statements separated by semicolons.
Return Values
Zero if the statement was successful. Nonzero if an error occurred.
MYSQL_RES *mysql_store_result(MYSQL *mysql)：保存執行完mysql_query（）的結果集
Description
After invoking mysql_query() or mysql_real_query(), you must call mysql_store_result() ormysql_use_result() for every statement that successfully produces a result set (SELECT, SHOW, DESCRIBE,EXPLAIN, CHECK TABLE, and so forth). You must also call mysql_free_result() after you are done with the result set.
You don't have to call mysql_store_result() or mysql_use_result() for other statements, but it does not do any harm or cause any notable performance degradation if you call mysql_store_result() in all cases. You can detect whether the statement has a result set by checking whether mysql_store_result() returns a nonzero value
void mysql_free_result(MYSQL_RES *result)：釋放結果集空間
Description
Frees the memory allocated for a result set by mysql_store_result(), mysql_use_result(),mysql_list_dbs(), and so forth. When you are done with a result set, you must free the memory it uses by calling mysql_free_result().
Do not attempt to access a result set after freeing it.
Return Values
None.
Errors
None.
void mysql_close(MYSQL *mysql)：斷開數據庫連接，釋放MYSQL結構體空間
Description
Closes a previously opened connection. mysql_close() also deallocates the connection handle pointed to bymysql if the handle was allocated automatically by mysql_init() or mysql_connect().
Return Values
None.
Errors
None.