iOS中 用FMDB封装一个SQLite数据库

建立一个单例：

DataBaseHandle.h

#import <Foundation/Foundation.h>
@class PersonModel;
@class FMDatabase;
@interface DataBaseHandle : NSObject
@property(nonatomic,retain)FMDatabase *db;
//创建单例的的接口
+ (DataBaseHandle *)shareDateBaseHandle;
//创建一个Person表格
- (void)creatPersonTable;
//插入person的方法
- (void)insertPersonTable : (PersonModel *)person;
//写一个删除人的接口
- (void)deletePersonByPerssonID : (NSString *)ID;
//写一个修改人的接口
- (void)uodatePerson : (NSString *)age ByPersonID : (NSString *)ID;
//写一个查询所有人的接口
- (NSMutableArray *)selectAllPersonFromPersonTable;
@end

DataBaseHandle.m

#import "DataBaseHandle.h"
#import "FMDB.h"
#import "PersonModel.h"
@implementation DataBaseHandle
- (void)dealloc
{
    self.db = nil;
    [super dealloc];
}

创建单例的的接口：

//创建单例对象使其存在于静态区
static DataBaseHandle *handle = nil;
//创建单例的的借口
+ (DataBaseHandle *)shareDateBaseHandle{
    
    @synchronized(self){
        if (handle == nil) {
            handle = [[DataBaseHandle alloc]init];
            
            
        }
    }
    return handle;
}

写一个私有的方法，返回数据库的路径

- (NSString *)dbpath{
    return [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject] stringByAppendingPathComponent:@"db.sqlite"];
    
}

创建一个Person表格

//创建一个Person表格
- (void)creatPersonTable{
   //初始化数据库对象
    self.db = [FMDatabase databaseWithPath: [self dbpath]];
    //打开数据库
   BOOL isOpen = [self.db open];
    if (isOpen) {
        NSLog(@"打开成功");
        //创建表
     BOOL isCreat =   [self.db executeUpdate:@"create table if not exists Person(id integer primary key autoincrement,name text,gender text,age integer,salary integer)"];
        NSLog(@"%@",isCreat ? @"创建成功":@"创建失败");
        
    }else{
        NSLog(@"打开失败");
    }
}

//插入person的方法
- (void)insertPersonTable : (PersonModel *)person{
  BOOL isInsert =  [self.db executeUpdate:@"insert into Person(name,age)values(?,?)",person.name,person.age];
    NSLog(@"%@",isInsert ? @"插入成功":@"插入失败");
    
}

//写一个删除的接口
- (void)deletePersonByPerssonID : (NSString *)ID{
   BOOL isDelete = [self.db executeUpdate:@"delete from Person where id = ?",ID];
    NSLog(@"%@",isDelete ? @"删除成功":@"删除失败");
}

//写一个修改人的接口
- (void)uodatePerson : (NSString *)age ByPersonID : (NSString *)ID{
   BOOL isUpdate = [self.db executeUpdate:@"update Person set age = ? where id = ?",age,ID];
    NSLog(@"%@",isUpdate ? @"修改成功":@"修改失败");
}

//写一个查询所有人的接口
- (NSMutableArray *)selectAllPersonFromPersonTable{
    FMResultSet *set = [self.db executeQuery:@"select * from Person"];
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:0];
    while ([set next]) {
        NSInteger ID = [set intForColumn:@"id"];
        NSString *name = [set stringForColumn:@"name"];
        NSInteger age = [set intForColumn:@"age"];
        //创建Person对象存储信息
        PersonModel *p = [[PersonModel alloc]init];
        p.ID = [NSString stringWithFormat:@"%ld",ID];
        p.name = name;
        p.age = [NSString stringWithFormat:@"%ld",age];
        //添加到数组
        [array addObject:p];
        [p release];
    }
    return array;
}

PersonModel.h
#import <Foundation/Foundation.h>
@interface PersonModel : NSObject
@property(nonatomic,copy)NSString *ID;
@property(nonatomic,copy)NSString *name;
@property(nonatomic,copy)NSString *age;
@end

PersonModel.m
#import "PersonModel.h"

@implementation PersonModel
- (void)dealloc
{
    self.name = nil;
    self.age = nil;
    self.ID = nil;
    [super dealloc];
}
@end

#import "FirstViewController.h"
#import "DataBaseHandle.h"
#import "PersonModel.h"
@interface FirstViewController ()
@property(nonatomic,retain)NSMutableArray *dataSource;//接收查询的结果
@end

@implementation FirstViewController
- (void)dealloc
{
    self.dataSource = nil;
    [super dealloc];
}

//懒加载
- (NSMutableArray *)dataSource{
    if (_dataSource == nil) {
        self.dataSource = [NSMutableArray arrayWithCapacity:0];
    }
    
    return [[_dataSource retain]autorelease];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    //调用并验证
    [[DataBaseHandle shareDateBaseHandle]creatPersonTable];
    NSLog(@"%@",NSHomeDirectory());
    PersonModel *p = [[PersonModel alloc]init];
    p.name = @"小韩哥";
    p.age = @"20";
    //调用插入person的方法
//    [[DataBaseHandle shareDateBaseHandle]insertPersonTable:p];
    
    //接收数据库返回的查询结果
    self.dataSource = [[DataBaseHandle shareDateBaseHandle]selectAllPersonFromPersonTable];
    
    //调用删除人的方法
    [[DataBaseHandle shareDateBaseHandle]deletePersonByPerssonID:@"9"];
    
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    // Return the number of rows in the section.
    return self.dataSource.count;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"firstcell" forIndexPath:indexPath];
    PersonModel *p = self.dataSource[indexPath.row];
    cell.textLabel.text = p.name;

    return cell;
}

提示：重在封装SQLite思想，不在效果，能有效调用即可！