IOS-SQLite数据库操作

Objective-c通过FMDB操作SQLite数据库的步骤：

1.安裝FMDB

下载FMDB

引入相关文件

2.打开数据库

NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

       //创建表（FMDB中只有update和query操作，出了查询其他都是update操作）

[database executeUpdate:@"create table user (name text,gender text,age integer)"];

//插入数据

BOOL insert = [database executeUpdate:@"insert into user values (?,?,?)",               self.nameTextField.text,self.genderTextField.text,self.ageTextField.text];

//不需要像Android中那样关闭Cursor关闭FMResultSet，因为相关的数据库关闭时，FMResultSet也会被自动关闭

FMResultSet *resultSet = [database executeQuery:@"select * from user"];

//参数必须是NSObject的子类，int,double,bool这种基本类型，需要封装成对应的包装类才可以

BOOL update = [database executeUpdate:@"update user set name = ? where age = ?",@"liu",[NSNumber numberWithInt:24]];

//删除数据

BOOL delete = [database executeUpdate:@"delete from user where name = ?",@"liuyinghui"];

4.关闭数据库

      [databaseQueue close];

项目实战

1.在Xcode6.2下新建一个Single View Application工程，命名为SaliteModel。

引入FMDB，添加支持库libsqlite3.dylib

2.  在界面上添加控件并关联属性

关联属性

@property (strong, nonatomic) IBOutlet UITextField *nameTextField;

@property (strong, nonatomic) IBOutlet UITextField *genderTextField;

@property (strong, nonatomic) IBOutlet UITextField *ageTextField;

//点击按钮后执行保存到数据库的操作

- (IBAction)saveButtonClicked:(id)sender {

//获取Document文件夹下的数据库文件，没有则创建

NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

//获取数据库并打开

FMDatabase *database  = [FMDatabase databaseWithPath:dbPath];

if (![database open]) {

NSLog(@"Open database failed");

return;

}

//创建表（FMDB中只有update和query操作，出了查询其他都是update操作）

[database executeUpdate:@"create table user (name text,gender text,age integer)"];

//插入数据

BOOL insert = [database executeUpdate:@"insert into user values (?,?,?)", self.nameTextField.text,self.genderTextField.text,self.ageTextField.text];

if (insert) {

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"保存成功" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];

[alert show];

}

[database close];

}

//点击按钮后执行查询操作

- (IBAction)queryButtonTapped:(id)sender {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentPath = [paths objectAtIndex:0];

NSString *dbPath = [documentPath stringByAppendingPathComponent:@"user.db"];

FMDatabase *database = [FMDatabase databaseWithPath:dbPath];

if (![database open]) {

return;

}

//不需要像Android中那样关闭Cursor关闭FMResultSet，因为相关的数据库关闭时，FMResultSet也会被自动关闭

FMResultSet *resultSet = [database executeQuery:@"select * from user"];

while ([resultSet next]) {

NSString *name = [resultSet stringForColumn:@"name"];

NSString *gender = [resultSet stringForColumn:@"gender"];

int age = [resultSet intForColumn:@"age"];

NSLog(@"Name:%@,Gender:%@,Age:%d",name,gender,age);

}

[database close];

//这里也不需要release

//    [database release];

}

//执行条件查询操作

- (IBAction)queryByConditionBtnTapped:(id)sender {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *docPath = [paths objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

FMDatabase *database = [FMDatabase databaseWithPath:dbPath];

if (![database open]) {

return;

}

FMResultSet *resultSet = [database executeQuery:@"select * from user where name = ?",@"Ryan"];

while ([resultSet next]) {

NSString *name = [resultSet stringForColumn:@"name"];

NSString *gender = [resultSet stringForColumn:@"gender"];

int age = [resultSet intForColumn:@"age"];

NSLog(@"Name:%@,Gender:%@,Age:%d",name,gender,age);

}

[database close];

}

//执行更新操作

- (IBAction)updateBtnTapped:(id)sender {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *docPath = [paths objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

FMDatabase *database = [FMDatabase databaseWithPath:dbPath];

if (![database open]) {

return;

}

//参数必须是NSObject的子类，int,double,bool这种基本类型，需要封装成对应的包装类才可以

BOOL update = [database executeUpdate:@"update user set name = ? where age = ?",@"liuyinghui",[NSNumber numberWithInt:24]];

if(update){

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"更新成功" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];

[alert show];

}

[database close];

}

- (IBAction)deleteBtnTapped:(id)sender {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *docPath = [paths objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

FMDatabase *database = [FMDatabase databaseWithPath:dbPath];

if (![database open]) {

return;

}

BOOL delete = [database executeUpdate:@"delete from user where name = ?",@"liuyinghui"];

if (delete) {

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

[alert show];

}

[database close];

}

-(void)executeDBOperation

{

//获取Document文件夹下的数据库文件，没有则创建

NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

NSString *dbPath = [docPath stringByAppendingPathComponent:@"user.db"];

FMDatabaseQueue *databaseQueue = [FMDatabaseQueue databaseQueueWithPath:dbPath];

[databaseQueue inDatabase:^(FMDatabase *db){

[db executeUpdate:@"insert into user values (?,?,?)",@"Ren",@"Male",[NSNumber numberWithInt:20]];

}];

[databaseQueue close];

}