iphone数据库（sqlite3）的用法操作

首先你在用之前要在项目中加入libsqlite3.dylib

1、定义模型

[cpp] #import <Foundation/Foundation.h>
#import "sqlite3.h"
@class NotePad;
@class NoteDb;
@inte易做图ce NoteSqlite : NSObject{
    sqlite3 *database;
    sqlite3_stmt *statement;
    char *errorMsg;
}
//打开数据库
-(BOOL)open;
//创建青
-(BOOL)create;

//增加、删除、修改、查询
-(BOOL)insert:(NotePad*)aNote;
-(BOOL)deleteALLNote;
-(BOOL)deleteaNote:(NotePad*)aNote;
-(BOOL)update:(NotePad*)aNote;

-(NoteDb*)selecteAll;
-(NoteDb*)selectNotes:(NotePad*)aNote;

@end
#import <Foundation/Foundation.h>
#import "sqlite3.h"
@class NotePad;
@class NoteDb;
@inte易做图ce NoteSqlite : NSObject{
    sqlite3 *database;
    sqlite3_stmt *statement;
    char *errorMsg;
}
//打开数据库
-(BOOL)open;
//创建青
-(BOOL)create;

//增加、删除、修改、查询
-(BOOL)insert:(NotePad*)aNote;
-(BOOL)deleteALLNote;
-(BOOL)deleteaNote:(NotePad*)aNote;
-(BOOL)update:(NotePad*)aNote;

-(NoteDb*)selecteAll;
-(NoteDb*)selectNotes:(NotePad*)aNote;

@end

2、实现方法

[cpp] #import "NoteSqlite.h"
#import "NotePad.h"
#import "NoteDb.h"
@implementation NoteSqlite

-(id)init{
    self=[super init];
    return self;
}
//打开数据库
-(BOOL)open{
    NSArray *paths= NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"noteList.db"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL find = [fileManager fileExistsAtPath:path];
    //判断文件是否存在
    if (find) {
        NSLog(@"数据库文件已经存在");
        //打开数据库、返回操作是否正确
        if(sqlite3_open([path UTF8String], &database) == SQLITE_OK) {
            NSLog(@"打开成功数据库");
        }
        return YES;
    }else{
        if(sqlite3_open([path UTF8String], &database) == SQLITE_OK) {
            //调用createMusicList创建数据库和表
            [self create];
            return YES;
        } else {
            sqlite3_close(database);
            NSLog(@"Error: open database file.");
            return NO;
        }
        return NO;
    }

}
//创建表
-(BOOL)create{
    //创建表语句
    const char *createSql="create table if not exists note (id integer primary key autoincrement,theme text,information text,ndate text,priority integer)";
    //创建表是否成功
    if (sqlite3_exec(database, createSql, NULL, NULL, &errorMsg)==SQLITE_OK) {
        NSLog(@"create ok.");
        return YES;
    }else{
        //打印出错信息
        NSLog(@"error: %s",errorMsg);
        sqlite3_free(errorMsg);
    }
    return NO;

}

//增加、删除、修改、查询
-(BOOL)insert:(NotePad*)aNote{
    //向表中插入记录
    //定义一个sql语句
    NSString *insertStatementNS = [NSString stringWithFormat:
                                   @"insert into \"note\"\
                                   (theme, information, ndate,priority)\
                                   values (\"%@\", \"%@\", \"%@\",%d)",
                                   aNote.theme,aNote.information,[NSString stringWithFormat:@"%@",aNote.ndate],aNote.priority
                                    ];
    //将定义的NSString的sql语句，转换成UTF8的c风格的字符串
    const char *insertSql = [insertStatementNS UTF8String];
    //执行插入语句
    if (sqlite3_exec(database, insertSql, NULL, NULL, &errorMsg)==SQLITE_OK) {
        NSLog(@"insert ok.");
        return YES;
    }else{
        NSLog(@"error: %s",errorMsg);
        sqlite3_free(errorMsg);
    }
    return NO;

}
-(BOOL)deleteALLNote{
    //删除所有数据，条件为1>0永真
    const char

补充：移动开发 , IOS ,