Objective-C 使用MySQL数据库的教程

首先要确定系统里已经安装了mysql，我的mysql安装在/usr/local/mysql
新建一个工程，名字叫 mysqlTest
修 改工程的设置，修改Orther Link Flags，加入-L/usr/local/mysql/lib -lmysqlclient -lz -lm -lmygcc，如图 

这个"-L/usr/local/mysql/lib -lmysqlclient -lz -lm -lmygcc" 是通过执行 /usr/local/mysql/bin/mysql_config --libs得到的，不同版本的mysql会有不通的输出
修改头文件和库文件的路径Header Search Path和Library Search Path，如图 


新建一个类，名字叫mysqlDB，扩展名修改成.mm，不是.m， 这个非常重要，如果是.m的文件，不能在文件内部写c的代码，使用mysql api，其实是用c写的
mysqlDB.h

#import #import   @interface mysqlDB : NSObject {     MYSQL *myconnect; } // 连接mysql -(void)connectHost:(NSString *)host connectUser:(NSString *)user connectPassword:(NSString *)password connectName:(NSString *)name; // 关闭连接 -(void)disconnect; // 执行query -(int)query:(NSString *)sql; // 返回结果集 -(MYSQL_RES *)store_result; // fetch结果集 -(NSMutableArray *)fetchRow:(MYSQL_RES *)result; -(NSMutableArray *)fetchAllRows:(MYSQL_RES *)result; @end

mysqlDB.mm

#import "mysqlDB.h"     @implementation mysqlDB -(id)init {     [super init];     return self; }   -(void)connectHost:(NSString *)host connectUser:(NSString *)user connectPassword:(NSString *)password connectName:(NSString *)name {     myconnect = mysql_init(myconnect);     myconnect = mysql_real_connect(myconnect,[host UTF8String],[user UTF8String],[password UTF8String],[name UTF8String],MYSQL_PORT,NULL,0); }   -(void)disconnect {     mysql_close(myconnect);     NSLog(@"Close From Mysql"); }   -(int)query:(NSString *)sql {     return mysql_query(myconnect, [sql UTF8String]); }   -(MYSQL_RES *)store_result {     return mysql_store_result(myconnect); }   -(NSMutableArray *)fetchRow:(MYSQL_RES *)result {     MYSQL_ROW row;     NSMutableArray *rowArray = [[NSMutableArray alloc] init];     int fieldCount = mysql_field_count(myconnect);     if(row = mysql_fetch_row(result))     {         for(int i = 0; i < fieldCount; i++)         {             /*             NSString *tmpStr = [[NSString alloc] initWithUTF8String:row[i]];             [rowArray addObject:tmpStr];             [tmpStr autorelease];              */             [rowArray addObject:[[NSString stringWithUTF8String:row[i]] autorelease]];         }     }     row = NULL;          [rowArray autorelease];     return rowArray; }   -(NSMutableArray *)fetchAllRows:(MYSQL_RES *)result {     NSMutableArray *resultArray = [[NSMutableArray alloc] init];     int rowCount = mysql_num_rows(result);     for(int i = 0; i < rowCount; i++)     {         //printf("%d\n",i);         [resultArray addObject:[self fetchRow:result]];     }     [resultArray autorelease];     return resultArray; } @end

在 mysqlTest.m文件中加入

mysqlDB *newMysql = [[mysqlDB alloc] init];     [newMysql connectHost:@"localhost" connectUser:@"root" connectPassword:@"" connectName:@"mysql"];     [newMysql query:@"SELECT * FROM user"];          NSMutableArray *result = [newMysql fetchAllRows:[newMysql store_result]];     //NSLog(@"%d",[result count]);     for(int i = 0; i < [result count]; i++)     {         //NSMutableArray *row = [result objectAtIndex:i];         NSMutableArray *row = [[NSMutableArray alloc] initWithArray:[result objectAtIndex:i]];         NSLog(@"\n%d:\n\t host:%@ \n\t user:%@",(i+1),[row objectAtIndex:0],[row objectAtIndex:1]);         [row release];     }     [result release];     [newMysql disconnect];

编译执行，就看到结果了