FMDB实用攻略

一.首先创建模型类

User.h

#import <Foundation/Foundation.h>

@interface User : NSObject

@property(nonatomic,assign)NSInteger ids;

@property(nonatomic,strong)NSString *name;

@property(nonatomic,strong)NSString *classes;

@property(nonatomic,strong)NSString *grade;

@end

二.创建数据库的单例类　FMDBData

FMDBData.h

@interface FMDBData : NSObject

//单例类

+(instancetype)sharedFMDBData;

//增加数据自定义方法

-(BOOL)insertUser:(User *)user;

//删除数据自定义方法

-(BOOL)deleteUser:(User *)user;

//修改数据自定义方法

-(BOOL)updateUser:(User *)user;

//查询数据自定义方法

-(NSMutableArray *)getAll;

//查询单个数据

-(User *)getMessage:(NSString *)name;

@end

FMDBData.m

导入FMDB头文件

#import "FMDatabase.h"

//全局静态变量

//数据库

static FMDatabase *fmdb;

//对象

static FMDBData *DBdata;

@implementation FMDBData

//创建单例类的方法 - dispatch_once   只执行一次

+(instancetype)sharedFMDBData

{

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

DBdata = [[FMDBData alloc]init];

[DBdata initDB];

});

return DBdata;

}

+(instancetype)allocWithZone:(struct _NSZone *)zone

{

if (!DBdata) {

DBdata = [super allocWithZone:zone];

}

return DBdata;

}

-(id)copy

{

return self;

}

-(id)mutableCopy

{

return self;

}

-(void)initDB

{

//沙盒路径

NSString *doucmentPach = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];

//拼接路径

NSString *pach = [doucmentPach stringByAppendingString:@"user.sqlite"];

//根据路径创建数据库

fmdb = [[FMDatabase alloc]initWithPath:pach];

if ([fmdb open]) {

//创建数据表

[fmdb executeUpdate:@"create table user(ids integer primary key autoincrement, name text, classes text, grade text)"];

NSLog(@"创建成功");

[fmdb close];

}

else

{

NSLog(@"创建失败");

}

}

//实现增加数据自定义方法

-(BOOL)insertUser:(User *)user

{

[fmdb open];

NSLog(@"%@",user.name);

BOOL isb = [fmdb executeUpdate:@"insert into user values (null,?,?,?)",user.name,user.classes,user.grade];

if (isb) {

NSLog(@"插入成功");

}

else

{

NSLog(@"插入失败");

}

[fmdb close];

return isb;

}

//实现删除数据自定义方法

-(BOOL)deleteUser:(User *)user

{

[fmdb open];

NSLog(@"%@",user.name);

BOOL isb = [fmdb executeUpdate:@"delete from user where name = ?",user.name];

if (isb) {

NSLog(@"删除成功");

}

else

{

NSLog(@"删除失败");

}

[fmdb close];

return isb;

}

//实现修改自定义方法

-(BOOL)updateUser:(User *)user

{

[fmdb open];

NSLog(@"%@",user.name);

NSString *str = [NSString stringWithFormat:@"update user set name = '%@' , classes = '%@' , grade = '%@' where ids = %ld",user.name,user.classes,user.grade,user.ids];

BOOL isb = [fmdb executeUpdate:str];

if (isb) {

NSLog(@"修改成功");

}

else

{

NSLog(@"修改失败");

}

[fmdb close];

return isb;

}

//查询所有

-(NSMutableArray *)getAll

{

//打开数据库

[fmdb open];

//创建可变数组

NSMutableArray *arr = [NSMutableArray array];

//创建结果对象接受数据库的操作结果

FMResultSet *fmset = [fmdb executeQuery:@"select * from user"];

//通过循环

while ([fmset next])

{

User *user = [[User alloc] init];

//用模型类对象接受数据库内容

user.ids = [fmset intForColumn:@"ids"];

user.name = [fmset stringForColumn:@"name"];

user.classes = [fmset stringForColumn:@"classes"];

user.grade = [fmset stringForColumn:@"grade"];

NSLog(@"%@",user.classes);

//将内容加入数组

[arr addObject:user];

}

//关闭数据库

[fmdb close];

return arr;

}

//查询单个数据

-(User *)getMessage:(NSString *)name

{

[fmdb open];

User *user = [[User alloc] init];

FMResultSet *fmset = [fmdb executeQuery:@"select * from user where name = ?",name];

while ([fmset next])

{

user.ids = [fmset intForColumn:@"ids"];

user.name = [fmset stringForColumn:@"name"];

user.classes = [fmset stringForColumn:@"classes"];

user.grade = [fmset stringForColumn:@"grade"];

}

[fmdb close];

return user;

}

@end

三.单例类的使用

1.删除按钮

- (IBAction)DeleteBtn:(id)sender {

//初始化FMDB

FMDBData *handle = [FMDBData sharedFMDBData];

//初始化单例类

User *user = [[User alloc] init];

//为 单例类的name赋值

user.name = self.NameTF.text;

//执行删除事件

BOOL isb =  [handle deleteUser:user];

// [table reloadData];

if (isb) {

[[[UIAlertView alloc] initWithTitle:@"提示" message:@"删除成功" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil] show];

}else{

[[[UIAlertView alloc] initWithTitle:@"提示" message:@"删除失败" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil] show];

}

[table reloadData];

}

2.查询按钮

- (IBAction)SelectBtn:(id)sender {

FMDBData *handle = [FMDBData sharedFMDBData];

if ([self.NameTF.text isEqualToString:@""]) {

arr = [handle getAll];

}

else

{

User *user=[handle getMessage:self.NameTF.text];

arr=[[NSMutableArray alloc]initWithObjects:user,nil];

}

[table reloadData];

}

3.添加按钮

-(void)click

{

//数据库

FMDBData *handle = [FMDBData sharedFMDBData];

//单例类

User *user = [[User alloc] init];

//保存数据

user.name = self.tfname.text;

user.classes = self.tfclass.text;

user.grade = self.tfscore.text;

//执行数据添加方法

BOOL isb =  [handle insertUser:user];

if (isb)

{

//

[self dismissViewControllerAnimated:YES completion:nil];

}

else

{

[[[UIAlertView alloc] initWithTitle:@"提示" message:@"保存失败" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil] show];

}

}

4更新按钮 (传参为数据模型体)

-(void)click

{

FMDBData *hander=[FMDBData sharedFMDBData];

self.user.name = self.tfname.text;

self.user.classes = self.tfclass.text;

self.user.grade = self.tfscore .text;

NSLog(@"id:%ld",self.user.ids);

BOOL isb =  [hander updateUser:self.user];

if (isb) {

[self dismissViewControllerAnimated:YES completion:nil];

}else{

[[[UIAlertView alloc] initWithTitle:@"提示" message:@"修改失败" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil] show];

}

}