sqlite3FMDB

附上 github链接https://github.com/15118130757/Fmdbuser
创建表

//拼接数据库的路径/Documents/fmdb.sqlite
    NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    NSString *dbPath = [documentsPath stringByAppendingPathComponent:@"fmdb.sqlite"];
    //数据库文件
    self.db = [FMDatabase databaseWithPath:dbPath];
    //连接数据库文件
    if ([self.db open]) {
        //创建表
        BOOL isSuccess = [self.db executeUpdate:@"create table if not exists Student (id integer primary key, name text, score real)"];
        if (!isSuccess) {
            NSLog(@"创建不成功==%@", [self.db lastError]);
        }
        NSLog(@"创建成功%@",dbPath);
    }
    //关闭数据库文件
    [self.db close];

插入值

if ([self.db open]) {
        //带有参数的插入SQL语句
        BOOL isSuccess = [self.db executeUpdateWithFormat:@"insert into Student (id,name, score) values (%ld,%@, %f)",15118130757,@"梁亚海", 120.0];
        if (!isSuccess) {
            NSLog(@"插入数据失败:%@", [self.db lastError]);
        }
        
        [self.db executeUpdateWithFormat:@"insert into Student (id,name, score) values (%ld,%@, %f)",15060193253,@"旋涡鸣人", 99.0];
          [self.db executeUpdateWithFormat:@"insert into Student (id,name, score) values (%ld,%@, %f)",13682631295,@"旋涡鸣人", 98.0];

    }
    [self.db close];

查询

   if ([self.db open]) {
        //查询(executeQuery)
//        FMResultSet *resultSet = [self.db executeQuery:@"select * from Student"];//查询所有
//        FMResultSet *resultSet=[self.db executeQuery:@"select * from Student where id=15118130757"];//查询数据库某一条数据
   FMResultSet *resultSet=[self.db executeQuery:@"select * from Student where name='旋涡鸣人'and id=15060193253"];//查询数据库某一条数据 多增加一个条件
        //循环
        while ([resultSet next]) {
            //选择方法
            NSString *nameStr = [resultSet stringForColumn:@"name"];
            double score = [resultSet doubleForColumn:@"score"];
            NSLog(@"%@,%f",nameStr,score);
        }

    }
    [self.db close];

删除

 if ([self.db open]) {
        BOOL isSuccess = [self.db executeUpdate:@"delete from Student where id=13682631295"];
        if (!isSuccess) {
            NSLog(@"删除失败:%@", [self.db lastError]);
        }
    }
    [self.db close];

更改

    if ([self.db open]) {
        BOOL isSuccess = [self.db executeUpdate:@"update Student set score=1028 where id=15118130757"];
        if (!isSuccess) {
            NSLog(@"修改失败:%@", [self.db lastError]);
        }
    }
    [self.db close];

增加数据库字段

 if ([self.db open]) {
        //判断字段是否存在
        if (![self.db columnExists:@"age" inTableWithName:@"Student"]) {
            
            NSString *sql = [NSString stringWithFormat:@"ALTER TABLE %@ ADD %@",@"Student",@"age"];
            BOOL ret = [self.db executeUpdate:sql];
            if (ret  != YES) {
                NSLog(@"add albumName fail");
            }
        }
        [self.db close];
    }