• 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, @""] && isSucced;
    20         isSucced = [db executeUpdate:@"insert into t_student (name, age, sex) values (?, ?, ?)", @"石兰", @12, @""] && isSucced;
    21         isSucced = [db executeUpdate:@"insert into t_student (name, age, sex) values (?, ?, ?)", @"卫庄", @34, @""] && 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 }
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  • 原文地址:https://www.cnblogs.com/zhizunbao/p/5543847.html
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