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【代码岛3】SQL教程！去而复返

用户:迷失冷光迷失冷光查看:6 回复:12 评论:6 创建时间:2020-10-21T20:01:07

今天我们要讨论的代码是去而复返

意思呢就是玩家离开再进入时会回到原来的位置

我也是和好几个人研究了半小时的结果

话不多说，直接上代码

首先，要创建一个SQL表格：

//创造SQL表格
db.sql`CREATE TABLE IF NOT EXISTS leaderboard(
    id VARCHAR(500) PRIMARY KEY UNIQUE NOT NULL,
    x REAL NOT NULL,
    y REAL NOT NULL,
    z REAL NOT NULL,
)`

id可以保存人的boxId

这样改名数据也不会丢失啦！

x，y，z是坐标的三个分量

接着，我们设置玩家没有存档时的初始位置：

const joinPosition = new Box3Vector3(128,55,128);//设置玩家出生点

（数据可修改）

然后，在玩家进入时

如果玩家有数据时就移动到指定地点

否则就移动到初始地点：

world.onPlayerJoin(async({entity})=>{
    const rows =  await db.sql`SELECT * FROM leaderboard WHERE id = ${entity.player.boxId}`;//判断玩家数据是否为空
    if(rows && !rows.length){//如果玩家没有数据
        entity.position = joinPosition;//将玩家移动到出生点
        await db.sql`INSERT INTO leaderboard(id,x,y,z) VALUES (${entity.player.boxId},${joinPosition.x},${joinPosition.y},${joinPosition.z})`;//初始位置
    }else{//否则
        const id = entity.player.boxId;
        for await(const row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY x ASC LIMIT 1`){//查找玩家数据
            var x = row.x;
        }
        for await(const row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY y ASC LIMIT 1`){//查找玩家数据
            var y = row.y;
        }
        for await(const row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY z ASC LIMIT 1`){//查找玩家数据
            var z = row.z;
        }
        entity.position.set(x,y,z);//将玩家移动到数据点
    }
})

最后，在玩家离开时保存数据：

world.onPlayerLeave(({entity})=>{
    db.sql`UPDATE leaderboard SET x = ${entity.position.x} WHERE id = ${entity.player.boxId}`; 
    db.sql`UPDATE leaderboard SET y = ${entity.position.y} WHERE id = ${entity.player.boxId}`; 
    db.sql`UPDATE leaderboard SET z = ${entity.position.z} WHERE id = ${entity.player.boxId}`; 
})

那我的本期讲解就到此结束啦!

emotion_编程猫_加油

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传奇无敌传奇无敌

emmmmm挺好的，终于有sql教程了

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西伯利亚狐西伯利亚狐

很好，以后就参考你的了，同志。

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指令者指令者

emotion_编程猫_加油

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指令者指令者

完整代码：

//创造SQL表格
db.sql`CREATE TABLE IF NOT EXISTS leaderboard(
    id VARCHAR(500) PRIMARY KEY UNIQUE NOT NULL,
    x REAL NOT NULL,
    y REAL NOT NULL,
    z REAL NOT NULL,
)`
c喵t joinPosition = new Box3Vector3(128,55,128);//设置玩家出生点
world.onPlayerJoin(async({entity})=>{
    c喵t rows =  await db.sql`SELECT * FROM leaderboard WHERE id = ${entity.player.boxId}`;//判断玩家数据是否为空
    if(rows && !rows.length){//如果玩家没有数据
        entity.position = joinPosition;//将玩家移动到出生点
        await db.sql`INSERT INTO leaderboard(id,x,y,z) VALUES (${entity.player.boxId},${joinPosition.x},${joinPosition.y},${joinPosition.z})`;//初始位置
    }else{//否则
        c喵t id = entity.player.boxId;
        for await(c喵t row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY x ASC LIMIT 1`){//查找玩家数据
            var x = row.x;
        }
        for await(c喵t row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY y ASC LIMIT 1`){//查找玩家数据
            var y = row.y;
        }
        for await(c喵t row of db.sql`SELECT * FROM leaderboard WHERE id = ${id} ORDER BY z ASC LIMIT 1`){//查找玩家数据
            var z = row.z;
        }
        entity.position.set(x,y,z);//将玩家移动到数据点
    }
})
world.onPlayerLeave(({entity})=>{
    db.sql`UPDATE leaderboard SET x = ${entity.position.x} WHERE id = ${entity.player.boxId}`; 
    db.sql`UPDATE leaderboard SET y = ${entity.position.y} WHERE id = ${entity.player.boxId}`; 
    db.sql`UPDATE leaderboard SET z = ${entity.position.z} WHERE id = ${entity.player.boxId}`; 
})

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指令者指令者

https://box3create.codemao.cn/games/4b6ca3d7b337e0495b04

会报错

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神岛吉吉喵神岛吉吉喵

建议的改进：

(async function() {
    console.clear();
    await db.sql`CREATE TABLE IF NOT EXISTS players (
        id VARCHAR(16) PRIMARY KEY UNIQUE NOT NULL,
        x REAL NOT NULL,
        y REAL NOT NULL,
        z REAL NOT NULL
    )`
}());

const joinPosition = new Box3Vector3(128,55,128);//设置玩家出生点

world.onPlayerJoin(async({entity})=>{
    const rows =  await db.sql`SELECT x,y,z FROM players WHERE id = ${entity.player.userKey}`;//判断玩家数据是否为空
    if(rows && !rows.length){//如果玩家没有数据
        entity.position = joinPosition;//将玩家移动到出生点
        await db.sql`INSERT INTO players(id, x, y, z) VALUES (${entity.player.userKey}, ${joinPosition.x}, ${joinPosition.y}, ${joinPosition.z})`;//初始位置
    }else{//否则
        const {x, y, z} = rows[0];
        entity.position.set(x,y,z);//将玩家移动到数据点        
    }
})

world.onPlayerLeave(({entity})=>{
  db.sql`UPDATE players SET x = ${entity.position.x}, y = ${entity.position.y}, z = ${entity.position.z} WHERE id = ${entity.player.userKey}`;
})

 

emotion_编程猫_加油

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该账号已被封禁该账号已被封禁

BCM世上第一个除吉吉喵外能发个SQL教程的人出现了！教程球！

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迷失冷光迷失冷光

//继续改进：
db.sql`CREATE TABLE IF NOT EXISTS pos(
    id VARCHAR(16) PRIMARY KEY UNIQUE NOT NULL,
    x REAL NOT NULL,
    y REAL NOT NULL,
    z REAL NOT NULL
)`
const joinPosition = new Box3Vector3(x,y,z);//出生点
world.onPlayerJoin(({entity})=>{
    const rows = await db.sql`SELECT * FROM pos WHERE id = ${entity.player.userKey}`;
    if(rows && rows.length){
        entity.position.copy(joinPosition);
        db.sql`INSERT INTO pos VALUES(${entity.player.userKey},0,0,0)`;
    }else{
        const row = rows[0];
        entity.position.set(row.x,row.y,row.z);
    }
})
world.onPlayerLeave(({entity})=>{
    db.sql`UPDATE pos SET x = ${entity.position.x},y = ${entity.position.y},z = ${entity.position.z} WHERE id = ${entity.player.userKey}`;
})

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神岛吉吉喵神岛吉吉喵

emotion_编程猫_点赞

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该账号已被封禁该账号已被封禁

顶上去

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还是那个小橙子丫还是那个小橙子丫

imgsrc="https://static.cod喵/emoji/codemao/%E7%BC%96%E7%A8%8B%E7%8C%AB_%E7%82%B9%E8%B5%9E.gif"alt="emotion_编程猫_点赞"

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YLG_個YLG_個

牛哇牛哇（）

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