(MySQL) Add column if not exists?

(MySQL) Add column if not exists? - Printable Version

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+--- Thread: (MySQL) Add column if not exists? (/showthread.php?tid=660287)

(MySQL) Add column if not exists? - ByMatt20030 - 29.10.2018

Well, the title explains itselfs...

I want to make an MySQL query to add a column to a table only if that column not exists trough a gamemode. And i don't know how.

Any idea/help? i'm using this plugin

Re: (MySQL) Add column if not exists? - TheToretto - 29.10.2018

MySQL doesn't have the if exists function for that so what you'll have to do is:

Select the name of the column you're planning to create, if it returns a result, then the column exist, else you can go ahead and alter table.

Re: (MySQL) Add column if not exists? - ByMatt20030 - 29.10.2018

I understand but can you give me an example? (i'm using MySQL since 4 hours ago

)

Re: (MySQL) Add column if not exists? - Jefff - 30.10.2018

https://stackoverflow.com/questions/...table-with-sql

Re: (MySQL) Add column if not exists? - corne - 30.10.2018

I would highly recommend using MariaDB instead of MySQL if you're able to, it works exactly the same but has more features and I believe has slightly better performance by default as well (and most importantly, works with the MySQL plugin).

In MariaDB doing this is as simple as

Код:

ALTER TABLE table_name ADD COLUMN IF NOT EXISTS column_name tinyint(1) DEFAULT 0;

Re: (MySQL) Add column if not exists? - TheToretto - 30.10.2018

There you go, if it exists, it'll return the value 1 which is true, else 0 which is false.

pawn Код:

CMD:alter(playerid, params[])
{
    new query[128];
    mysql_format(Database, query, sizeof(query), "SHOW COLUMNS FROM `sa-mp_test` LIKE 'column1'");
    mysql_tquery(Database, query, "ColumnCheck");
    return 1;
}

forward ColumnCheck();
public ColumnCheck()
{
    printf("It returned the value %d", cache_num_rows());
    return 1;
}

Re: (MySQL) Add column if not exists? - ByMatt20030 - 30.10.2018

Quote:

Originally Posted by TheToretto

There you go, if it exists, it'll return the value 1 which is true, else 0 which is false.

pawn Код:

CMD:alter(playerid, params[])
{
    new query[128];
    mysql_format(Database, query, sizeof(query), "SHOW COLUMNS FROM `sa-mp_test` LIKE 'column1'");
    mysql_tquery(Database, query, "ColumnCheck");
    return 1;
}

forward ColumnCheck();
public ColumnCheck()
{
    printf("It returned the value %d", cache_num_rows());
    return 1;
}

I love you <3

@corne I'll think about it

@Jefff Thank you too! (i understand your reply, but i didn't know how to implement it correctly)