Question

我有迁移：

lass ChangeDefaultValueBodyForBlogPosts < ActiveRecord::Migration
  def up
    change_column :blog_posts, :body, :text, :null => false
    change_column :comments, :text, :text, :null => false
  end

  def down
    change_column :comments, :text, :text, :default => nil
    change_column :blog_posts, :body, :text, :default => nil
  end
end

rake db：migrate display error：

Mysql2 ::错误：BLOB，TEXT，GEOMETRY或JSON列'body'不能有默认值：ALTER TABLE blog_posts CHANGE body body text DEFAULT ''NOT NULL / home / user / projects / projectname / db / migrate / 20120508203410_change_default_value_body_for_blog_posts.rb：3：in up up

我使用的是ubuntu 16.04，

mysql server 5.7（版本：5.7.12-0ubuntu1.1 版本：5.7.12-0ubuntu1 版本：5.7.11-0ubuntu6 ）

我在谷歌看了一下，解决这个问题需要改变

SQL模式= “STRICT_TRANS_TABLES，NO_AUTO_CREATE_USER，NO_ENGINE_SUBSTITUTION”

到

sql-mode="NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

但my.conf文件为空。

#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

如何解决这个问题，请帮忙。谢谢。

Answer 1

我找到了解决方案：需要在my.cnf中添加

[mysqld]
sql-mode="NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

Answer 2

你需要找到正确的my.cnf：

sudo find / -name "*.cnf"

/etc/mysql/mysql.conf.d/mysqld.cnf
/etc/mysql/my.cnf
/etc/mysql/mysql.cnf
/etc/mysql/conf.d/mysqldump.cnf
/etc/mysql/conf.d/mysql.cnf

我根据

编辑了/etc/mysql/mysql.conf.d/mysqld.cnf

strace mysql ";" 2>&1  | grep cnf

stat("/etc/my.cnf", 0x7ffda9472660)     = -1 ENOENT (No such file or directory)
stat("/etc/mysql/my.cnf", {st_mode=S_IFREG|0644, st_size=683, ...}) = 0
open("/etc/mysql/my.cnf", O_RDONLY)     = 3
stat("/etc/mysql/conf.d/mysql.cnf", {st_mode=S_IFREG|0644, st_size=8, ...}) = 0
open("/etc/mysql/conf.d/mysql.cnf", O_RDONLY) = 4
stat("/etc/mysql/conf.d/mysqldump.cnf", {st_mode=S_IFREG|0644, st_size=55, ...}) = 0
open("/etc/mysql/conf.d/mysqldump.cnf", O_RDONLY) = 4
stat("/etc/mysql/mysql.conf.d/mysqld.cnf", {st_mode=S_IFREG|0644, st_size=3034, ...}) = 0
open("/etc/mysql/mysql.conf.d/mysqld.cnf", O_RDONLY) = 4
stat("/etc/mysql/mysql.conf.d/mysqld_safe_syslog.cnf", {st_mode=S_IFREG|0644, st_size=21, ...}) = 0
open("/etc/mysql/mysql.conf.d/mysqld_safe_syslog.cnf", O_RDONLY) = 4
stat("/root/.my.cnf", 0x7ffda9472660)   = -1 ENOENT (No such file or directory)
stat("/root/.mylogin.cnf", 0x7ffda9472660) = -1 ENOENT (No such file or directory)

找到正确的文件后，在[mysqld]声明下面添加 sql-mode =＆＃34; NO_AUTO_CREATE_USER，NO_ENGINE_SUBSTITUTION＆＃34;

Answer 3

使用xampp的mysql在本地计算机上进行迁移时，我没有任何问题。仅在生产服务器上，它才开始出现故障。我发现xampp运行mariadb而不是普通的mysql。因此，在服务器上使用mariaDB解决了我的问题。

Answer 4

再次检查您的sql代码错误，上面的“ body”明确表示不是默认值
示例：

 `completed` text NOT NULL  DEFAULT 'false',

删除默认值

后

`completed` text NOT NULL,

现在希望您的错误已消失。对不起我的英语。

Answer 5

我是这样解决这个问题的：我曾经想在一台服务器上导出我的mySql数据库，然后在另一台服务器（CPanel主机）中导入它。每次我尝试时，phpMyAdmin 都会在其中一个数据库表的字段之一上出现此错误。然后我去了我的源主机；打开 phpMyAdmin 并打开该表结构并删除该字段的默认值。然后我再次导出，这次成功了。

Mysql2 ::错误：BLOB，TEXT，GEOMETRY或JSON列'body'不能有默认值

5 个答案: