IOS使用fmdb操作数据库的方法详解

一、导入头文件

1.第三方库的头文件

#import "FMDB.h"

2.导入数据模型的头文件

#import "MainPageModel.h"
二、各种方法

@interface MyFMDBInfo :
NSObject
{

//记录是否打开成功

BOOL _isOpenSuccess;

//创建数据库管理对象

FMDatabase * _dataBase;
}

//打开成功
- (BOOL)open;

//插入一条数据，表示新加入一条收藏
第一个参数表示插入的数据模型 第二个参数是标记
- (void)insertCollectionWithModel:(MainPageModel *)model andRecordType:(NSString
*)type;

//删除一条收藏记录
根据其cellId来删除
- (void)deleteOneCollentionWithCellId:(NSString *)cellId andRecordType:(NSString
*)type;

//判断正在浏览的这一项是否已经被收藏了
- (BOOL)isExistedWithCellId:(NSString *)cellId andRecordType:(NSString *)type;

//获取表中的信息
- (NSArray *)getdataInfoWithRecordType:(NSString *)type;

@end
三、方法的具体实现

@implementation MyFMDBInfo
- (void)dealloc {

//如果打开成功

if (_isOpenSuccess) {

//关闭数据库
[_dataBase
close];
}
}

//在构造方法中实例化数据库管理对象

- (instancetype)init {

if (self = [super
init]) {

//实例化管理对象

_dataBase = [FMDatabase
databaseWithPath:[self
dataBasePath]];

//初始化为没有打开

_isOpenSuccess =
NO;
}

return
self;
}

- (NSString *)dataBasePath {

return [NSString
stringWithFormat:@"%@/Documents/dataBase.rdb",NSHomeDirectory()];
}

#pragma mark - 创建数据库表 -
- (BOOL)open {

_isOpenSuccess = [_dataBase
open];

//如果没有打开数据库，就不用创建数据库表了

if (!_isOpenSuccess) {

return
_isOpenSuccess;
}

//创建一个收藏信息表

NSString * createCollectionInfoTable =
@"create table if not exists collectionInfoTable (id integer primary key,cellId text,title text,pic text,update_time text,url text,recordType)";

BOOL createSuccess = [_dataBase
executeUpdate:createCollectionInfoTable];

//如果创建成功，返回打开成功，如果创建失败，就当打开数据库失败，返回失败

if (!createSuccess) {
[_dataBase
close];

_isOpenSuccess =
NO;

return
_isOpenSuccess;
}

return
_isOpenSuccess;
}

#pragma mark - 对数据库的操作 -

//增加一条收藏
- (void)insertCollectionWithModel:(MainPageModel *)model andRecordType:(NSString
*)type {

//先判断当前浏览的项目是否已经被加到收藏栏中了

BOOL result = [self
isExistedWithCellId:model.id
andRecordType:type];

if (result) {

NSLog(@"当前正在浏览的项目已经添加到收藏栏中了");

return;
}

NSString * addInfoTable =
@"insert into collectionInfoTable (cellId,title,pic,update_time,url,recordType) values (?,?,?,?,?,?)";

BOOL isSuccess = [_dataBase
executeUpdate:addInfoTable,model.id,model.title,model.pic,model.update_time,model.url,type];

if (isSuccess) {

//NSLog(@"添加一条新的收藏记录成功");
}
else {

//NSLog(@"添加一条新的收藏记录失败");
}
}

//删除一条收藏记录
- (void)deleteOneCollentionWithCellId:(NSString *)cellId andRecordType:(NSString
*)type {

NSString * deleteInfoTable =
@"delete from collectionInfoTable where cellId = ? and recordType = ?";

BOOL isSuccess = [_dataBase
executeUpdate:deleteInfoTable,cellId,type];

if (isSuccess) {

//NSLog(@"删除一条新的收藏记录成功");
}
else {

//NSLog(@"删除一条新的收藏记录失败");
}

}

//读取收藏记录到表格中
- (NSArray *)getdataInfoWithRecordType:(NSString *)type {

NSString * collectionInfoTable =
@"select * from collectionInfoTable where recordType = ?";

FMResultSet * set = [_dataBase
executeQuery:collectionInfoTable,type];

NSMutableArray * modelArray = [[NSMutableArray
alloc]
init];

//固定格式

while ([set next]) {

MainPageModel * oneModel = [[MainPageModel
alloc] init];
oneModel.id = [set
stringForColumn:@"cellId"];
oneModel.title = [set
stringForColumn:@"title"];
oneModel.pic = [set
stringForColumn:@"pic"];
oneModel.url = [set
stringForColumn:@"url"];
oneModel.update_time = [set
stringForColumn:@"update_time"];
[modelArray
addObject:oneModel];
}

return modelArray;
}

//判断当前浏览项目是否已经添加到收藏里面了
- (BOOL)isExistedWithCellId:(NSString *)cellId andRecordType:(NSString *)type
{

NSString * collectionInfoTable =
@"select * from collectionInfoTable where cellId = ? and recordType = ?";

//先查询数据库
确定正在浏览的项目是否已经存在于收藏记录中了

FMResultSet * collectionInfoTableSet = [_dataBase
executeQuery:collectionInfoTable,cellId,type];

BOOL result = [collectionInfoTableSet
next];

if (result) {

//存在

return YES;
}
else {

//不存在

return NO;
}
}

@end
【注】数据库可以存储和管理数据，转变成用户所需的各种数据库管理的方式。