iOS开发 - FMDatabase 使用

    //_id integer primary key autoincrement 设置自增长主键 

    NSString * path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/sql.db"];

    //指定数据存储路径
    //FMDatabase 管理数据的类(增 删 改 查)
    FMDatabase * dataBase = [[FMDatabase alloc] initWithPath:path];
    //open 打开数据库/文件 如果文件存在,就是打开 如果文件不存在就是创建
    bool res = [dataBase open];

    if (res) {
        NSLog(@"文件创建成功");

        //创建表
        NSString * sql = @"CREATE TABLE IF NOT EXISTS userInfo(name text,age interger)";
        //CREATE TABLE IF NOT EXISTS
        //userInfo 表名
        //()内要存储的数据的个数以及类型
        //text 字符串类型 varchar 字符串 interger整形

        //执行sql语句 增删改都使用这个方法
        BOOL res = [dataBase executeUpdate:sql];
        if (res) {
            NSLog(@"创建表成功");
        }else{
            NSLog(@"创建表失败");
        }

        //添加数据
        NSString * insertSql = [NSString stringWithFormat:@"insert into userInfo (name,age) values(?,?)"] ;

        BOOL ret1 = [dataBase executeUpdate:insertSql,@"name",@12];
        BOOL ret1_1 = [dataBase executeUpdate:insertSql,@"name1",@12];
        BOOL ret1_2 = [dataBase executeUpdate:insertSql,@"name2",@12];
        if (ret1 && ret1_1 && ret1_2) {
            NSLog(@"插入数据成功");
        }else{
            NSLog(@"插入数据失败");
        }

        //修改数据
        NSString * updateSql = @"update userInfo set name=?,age=? where name=?";
        BOOL ret3 = [dataBase executeUpdate:updateSql,@"name1",@200,@"0"];
        if (ret3) {
            NSLog(@"修改成功");
        }
        else{
            NSLog(@"修改失败");
        }

        //删除
        NSString *deleteSql = @"delete from userInfo where name=?";
        BOOL ret4 = [dataBase executeUpdate:deleteSql,@"name1"];
        if (ret4) {
            NSLog(@"删除成功");
        }else{
            NSLog(@"删除失败");
        }

        //查看数据
        NSString * selectSql = @"select * from userInfo";
        FMResultSet * rs = [dataBase executeQuery:selectSql];
        //next逐条查询 查到了就查询下一条
        // BOOL ret2 = [rs next];
        while ([rs next]) {
            NSString * name = [rs stringForColumn:@"name"];
            NSInteger age = [rs intForColumn:@"age"];
            NSLog(@"%@",name);
        }
    }else{
        //lastErrorMessage 创建/打开数据库失败的错误信息
        NSLog(@"%@",dataBase.lastErrorMessage);
    }