为什么在我尝试创建外键时会出现一个错误，指出该列不存在

如何解决为什么在我尝试创建外键时会出现一个错误，指出该列不存在

我对 MysqL 和编写查询比较陌生。我正在尝试创建一个具有多种不同关系的数据库。我能够创建表并分配唯一索引，但是当我尝试更改每个表时，根据我尝试创建的外键，我得到相同的错误。这是我得到的错误：

错误代码：1072。表中不存在关键列“gameID”

这是我尝试打电话的时候

ALTER TABLE `tbl_player` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`);

下面是当前的 sql 脚本：

drop database if exists test_DB;
create database test_DB;
use test_DB;

drop procedure if exists createdb;  
delimiter //
create procedure createdb()
begin

/*leaderboard*/
drop table if exists tbl_leaderboard;   
CREATE TABLE `tbl_leaderboard` (
    `leaderboardID` INTEGER NOT NULL,`totalscore` INTEGER DEFAULT 0 NOT NULL,`gamesPlayed` INTEGER DEFAULT 0 NOT NULL,`averagescore` INTEGER DEFAULT 0 NOT NULL,CONSTRAINT SYS_PK_10503 PRIMARY KEY (`leaderboardID`)
);

/*User ===================================================================================*/ 
drop table if exists tbl_user; 
CREATE TABLE `tbl_user` (
    `userID` INTEGER NOT NULL,`username` VARCHAR(255) NOT NULL,`user_password` VARCHAR(20) NOT NULL,`user_email` VARCHAR(20) NOT NULL,`user_loginAttermpts` INTEGER DEFAULT 0 NOT NULL,`user_accountStatus` INTEGER DEFAULT 0 NOT NULL,`user_isAdmin` BOOLEAN NOT NULL,CONSTRAINT SYS_PK_10513 PRIMARY KEY (`userID`,`username`)
);

/*Player  ===================================================================================*/
drop table if exists tbl_player; 
CREATE TABLE `tbl_player` (
    `player_score` SMALLINT DEFAULT 0 NOT NULL,`playerID` SMALLINT NOT NULL,`colour` VARCHAR(20) NOT NULL,CONSTRAINT SYS_PK_10375 PRIMARY KEY (`player_score`,`playerID`)
);

/*Inventory ===================================================================================*/
drop table if exists tbl_inventory;
CREATE TABLE `tbl_inventory` (
    `inventoryID` INTEGER NOT NULL,`quantity` INTEGER DEFAULT 0 NOT NULL,CONSTRAINT SYS_PK_10520 PRIMARY KEY (`inventoryID`)
);

/*Tile ===================================================================================*/
drop table if exists tbl_tile;
CREATE TABLE `tbl_tile` (
    `tileID` INTEGER NOT NULL,CONSTRAINT SYS_PK_10547 PRIMARY KEY (`tileID`)
    
);

/*Board ===================================================================================*/
drop table if exists tbl_board;
CREATE TABLE `tbl_board` (
    `boardID` INTEGER NOT NULL,CONSTRAINT SYS_PK_10538 PRIMARY KEY (`boardID`)
    
);

/*Game ===================================================================================*/
drop table if exists tbl_game;
CREATE TABLE `tbl_game` (
    `gameID` INTEGER NOT NULL,`gameNumber` INTEGER DEFAULT 0 NOT NULL,`numberOfPlayers` INTEGER DEFAULT 0 NOT NULL,`gameMode` VARCHAR(30) NOT NULL,CONSTRAINT SYS_PK_10543 PRIMARY KEY (`gameID`)
);

/*Chat ===================================================================================*/
drop table if exists tbl_gameChat;
CREATE TABLE `tbl_gameChat` (
    `chatID` SMALLINT NOT NULL,`text` VARCHAR(255),CONSTRAINT SYS_PK_10555 PRIMARY KEY (`chatID`)
);

/*TileAsset ===================================================================================*/
drop table if exists tbl_assetTile;
CREATE TABLE `tbl_assetTile` (
    `assetTileID` INTEGER NOT NULL,CONSTRAINT SYS_PK_10545 PRIMARY KEY (`assetTileID`)
);

/*Asset ===================================================================================*/
drop table if exists tbl_asset;
CREATE TABLE `tbl_asset` (
    `assetID` INTEGER NOT NULL,`asset_name` VARCHAR(50) NOT NULL,`asset_type` VARCHAR(50) NOT NULL,`asset_value` INTEGER DEFAULT 0 NOT NULL,CONSTRAINT SYS_PK_10557 PRIMARY KEY (`assetID`)
);

/*Create UNIQUE Indexes*/
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10503_10504 ON `tbl_leaderboard` (`leaderboardID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10497_10498 ON `tbl_user` (`userID`,`username`);
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10513_10514 ON `tbl_user` (`userID`,`username`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10375_10376 ON `tbl_player` (`player_score`,`playerID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10520_10521 ON `tbl_inventory` (`inventoryID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10547_10548 ON `tbl_tile` (`tileID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10538_10539 ON `tbl_board` (`boardID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10543_10544 ON `tbl_game` (`gameID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10555_10556 ON `tbl_gameChat` (`chatID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10545_10546 ON `tbl_assetTile` (`assetTileID`);
    
    CREATE UNIQUE INDEX SYS_IDX_SYS_PK_10557_10558 ON `tbl_asset` (`assetID`);


/*Add Foreign Keys*/
    ALTER TABLE `tbl_player` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`);
    ALTER TABLE `tbl_player` ADD FOREIGN KEY (`tileID`) REFERENCES tbl_tile(`tileID`);
    ALTER TABLE `tbl_player` ADD FOREIGN KEY (`userID`) REFERENCES tbl_user(`userID`);
    
    ALTER TABLE `tbl_inventory` ADD FOREIGN KEY (`playerID`) REFERENCES tbl_player(`playerID`);
    ALTER TABLE `tbl_inventory` ADD FOREIGN KEY (`assetID`) REFERENCES tbl_asset(`assetID`);
    
    ALTER TABLE `tbl_tile` ADD FOREIGN KEY (`boardID`) REFERENCES tbl_board(`boardID`);
    
    ALTER TABLE `tbl_board` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`);
    
    ALTER TABLE `tbl_gameChat` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`);
    
    ALTER TABLE `tbl_assetTile` ADD FOREIGN KEY (`tileID`) REFERENCES tbl_tile(`tileID`);
    ALTER TABLE `tbl_assetTile` ADD FOREIGN KEY (`assetID`) REFERENCES tbl_asset(`assetID`);

    ALTER TABLE `tbl_leaderboard` ADD FOREIGN KEY (`player_score`) REFERENCES tbl_player(`player_score`);
    ALTER TABLE `tbl_leaderboard` ADD FOREIGN KEY (`userID`) REFERENCES tbl_user(`userID`);
    ALTER TABLE `tbl_leaderboard` ADD FOREIGN KEY (`username`) REFERENCES tbl_user(`username`);

    
end //

delimiter ;
call createdb();

对于如何解决此问题的任何建议以及对格式的可能改进将不胜感激。

解决方法

您的表 tbl_player 没有列 gameID 在您创建脚本中添加它以添加 FOREIGN KEY，这同样适用于您尝试添加的所有外键。该列必须在您愿意创建 FOREIGN KEY

的表中可用

CREATE TABLE `tbl_player` (
    `player_score` SMALLINT DEFAULT 0 NOT NULL,`playerID` SMALLINT NOT NULL,`colour` VARCHAR(20) NOT NULL,`gameID` INTEGER,CONSTRAINT SYS_PK_10375 PRIMARY KEY (`player_score`,`playerID`)
);

在为任何表创建外键之前，请确保该表包含/具有您要添加外键约束的列。

在您的情况下，如果您看到表 tbl_player（如您所共享）

/*Player  ===================================================================================*/
drop table if exists tbl_player; 
CREATE TABLE `tbl_player` (
    `player_score` SMALLINT DEFAULT 0 NOT NULL,`playerID`)
);

没有列 gameID 并且您正在运行的查询 ALTER TABLE `tbl_player` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`); 试图在列 gameID 上添加外键约束（这tbl_player 表中不存在） 从而导致您提到的错误 Error Code: 1072. Key column 'gameID' doesn't exist in table

要解决此问题，您可以：

更改表以添加新列，然后向该列添加外键约束：

ALTER TABLE tbl_player
  ADD COLUMN gameID INT,ADD FOREIGN KEY fk_name(gameID) REFERENCES tbl_game(gameID) ON DELETE CASCADE;

在创建表时添加列 gameID，如下所示：

/*Player  ===================================================================================*/
drop table if exists tbl_player; 
CREATE TABLE `tbl_player` (
    `player_score` SMALLINT DEFAULT 0 NOT NULL,`gameID` INTEGER NOT NULL,`playerID`)
);

然后更改表以创建列 gameID 作为外键：

ALTER TABLE tbl_player add FOREIGN KEY(gameID) REFERENCES tbl_game(gameID);

以上任何一点都应该有效。

干杯！！