Objective-C 使用MySQL数据库的教程

来源：互联网发布：期货交易者软件怎么样编辑：程序博客网时间：2024/05/16 07:49

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 <Cocoa/Cocoa.h>
#import <mysql.h>
@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