为什么在我尝试创建外键时会出现错误提示该列不存在

Question

I am relatively new to mysql and writing queries. I am trying to create a database that has multiple different relationships. I am able to create the tables and assign unique indexes, but when I try and alter each table, I get the same error depending on what Foreign Key I am trying to create. Here is the error I am getting:

Error Code: 1072. Key column 'gameID' doesn't exist in table

This is when I try and call

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

Below Is the current SQL script:

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();

Any suggestions on how to fix this issue would be greatly appreciated and possible improvements to the fomrmat.

Answer 1

Your table tbl_player doesn't have a column gameID add it in you create script to add the FOREIGN KEY , the same applies to all foreign keys you are trying to add. the column must be available in the table where you are willing to create the FOREIGN KEY

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`)
);

Answer 2

Before creating foreign keys for any table, make sure the table contains/has the column you are adding foreign key constraint to.

In your case if you see the table tbl_player (as you have shared)

/*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`)
);

does not have column gameID and the query you are running ALTER TABLE `tbl_player` ADD FOREIGN KEY (`gameID`) REFERENCES tbl_game(`gameID`); is trying to add Foreign key constraint on column gameID (which does not exists in the tbl_player table) thereby resulting into an error you mentioned Error Code: 1072. Key column 'gameID' doesn't exist in table

To solve this you can:

1. Alter table to add a new column and then add foreign key constraint to that column:

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

2. Add a column gameID while creating the table as below:

/*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,
    `gameID` INTEGER NOT NULL,
    CONSTRAINT SYS_PK_10375 PRIMARY KEY (`player_score`,`playerID`)
);

then alter the table to create column gameID as foreign key:

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

Any one of the above points should work.

Cheers!!