FMDB简单用法

首先引入类库

声明数据库和路径

/** 声明数据库对象 */

@property (nonatomic, strong) FMDatabase *dataBase;

/** 声明存储路径 */

@property (nonatomic, strong) NSString *filePath;

创建表：

 1 #pragma mark - 创建表
 2 - (void)createTable {
 3     
 4     // 1.创建sql语句
 5     NSString *str = @"create table if not exists t_student (id integer primary key autoincrement not null, name text not null, age integer not null, sex text not null)";
 6     
 7     // 2.找到存储路径
 8     NSString *document = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
 9     self.filePath = [document stringByAppendingPathComponent:@"student.sqlite"];
10     NSLog(@"filePath = %@", self.filePath);
11     
12     // 3.初始化FMDB对象
13     self.dataBase = [FMDatabase databaseWithPath:self.filePath];
14     
15     // 4.判断数据库打开的时候才执行语句
16     if ([self.dataBase open]) {
17         BOOL result = [self.dataBase executeUpdate:str];
18         
19         if (result) {
20             NSLog(@"创建表成功");
21         } else {
22             NSLog(@"创建表失败");
23         }
24     }
25     
26     // 5.关闭数据库
27     [self.dataBase close];
28 }

添加

 1 #pragma mark - 以队列方式插入多个学生【这种方式较为常用】
 2 - (IBAction)insertManyStudent:(id)sender {
 3     
 4     // FMDB不支持多个线程同时操作，所以一般以串行的方式实现相关的操作
 5     
 6     // 1.打开数据库
 7     [self.dataBase open];
 8     
 9     // 2.创建操作队列
10     FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:self.filePath];
11     
12     // 3.标识：记录是否操作成功
13     __block BOOL isSucced = YES;
14     
15     // 4.把所需要的事件打包放在操作队列中
16     [queue inTransaction:^(FMDatabase *db, BOOL *rollback) {
17         
18         // 串行队列
19         isSucced = [db executeUpdate:@"insert into t_student (name, age, sex) values (?, ?, ?)", @"高月", @10, @"女"] && isSucced;
20         isSucced = [db executeUpdate:@"insert into t_student (name, age, sex) values (?, ?, ?)", @"石兰", @12, @"女"] && isSucced;
21         isSucced = [db executeUpdate:@"insert into t_student (name, age, sex) values (?, ?, ?)", @"卫庄", @34, @"男"] && isSucced;
22         
23         // 如果有错误，就将它返回
24         if (!isSucced) {
25             // block返回的参数rollback进行处理(bool类型的指针)
26             *rollback = YES;
27             return;
28         } else {
29             NSLog(@"插入成功");
30         }
31     }];
32     
33     // 5.关闭数据库
34     [self.dataBase close];
35 }

更改

 1 #pragma mark - 更改学生
 2 - (IBAction)updateAction:(id)sender {
 3     
 4     // 1.打开数据库
 5     [self.dataBase open];
 6     
 7     // 2.执行语句
 8     BOOL result = [self.dataBase executeUpdate:@"update t_student set name = ? where name = ?", @"少羽", @"卫庄"];
 9     if (result) {
10         NSLog(@"更改成功");
11     } else {
12         NSLog(@"%d", result);
13         NSLog(@"更改失败");
14     }
15     
16     // 3.关闭数据库
17     [self.dataBase close];
18 }

删除

 1 #pragma mark - 删除学生
 2 - (IBAction)deleteAction:(id)sender {
 3     
 4     // 1.打开数据库
 5     [self.dataBase open];
 6     
 7     // 2.执行sql语句
 8     BOOL result = [self.dataBase executeUpdate:@"delete from t_student where name = ?", @"少羽"];
 9     if (result) {
10         NSLog(@"删除成功");
11     } else {
12         NSLog(@"删除失败");
13     }
14     
15     // 3.关闭数据库
16     [self.dataBase close];
17 }

查询所有

 1 // 查询所有
 2 - (NSMutableArray *)searchAll {
 3     
 4     [self.dataBase open];
 5     FMResultSet *resultSet = [self.dataBase executeQuery:@"select *from p_person"];
 6     NSMutableArray *array = [NSMutableArray array];
 7     while ([resultSet next]) {
 8         Person *person = [[Person alloc] init];
 9         person.id = [resultSet intForColumn:@"id"];
10         person.name = [resultSet objectForColumnName:@"name"];
11         person.age = [resultSet intForColumn:@"age"];
12         person.weight = [resultSet doubleForColumn:@"weight"];
13         
14         [array addObject:person];
15     }
16     [self.dataBase close];
17     return array;
18 }