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Eager load polymorphic
...< ActiveRecord::Base
has_many :reviews, as: :reviewable
end
You are unable to do that query for several reasons.
ActiveRecord is unable to build the join without additional information.
There is no table called reviewable
To solve this issue, you need to explicitly define the relationsh...
List all svn:externals recursively?
...tSvnRevs() {
cd "$1"
wcver="$(svnversion)"
[ -n "$wcver" ] || panic "Unable to get version for $wcdir"
echo "$1: $wcver"
svn propget svn:externals -R | while read a b c d e; do
[ -n "$a" ] || continue
if [ "$b" = "-" ]; then
wcparent="$a"
wcdir="$wcparent/$c"
[ -z...
Reading a file line by line in Go
I'm unable to find file.ReadLine function in Go. I can figure out how to quickly write one, but I am just wondering if I'm overlooking something here. How does one read a file line by line?
...
how to check the dtype of a column in python pandas
...empty pd.Series or pd.DataFrames but has another problems.
First - it is unable to differ some dtypes:
df = pd.DataFrame({'prd' :[pd.Period('2002-03','D'), pd.Period('2012-02-01', 'D')],
'str' :['s1', 's2'],
'cat' :[1, -1]})
df['cat'] = df['cat'].astype('c...
单选框使用指导 · App Inventor 2 中文网
...的按钮、标签、布局等组件，按案例中的名称重命名。先运行最小案例，确认事件返回，再增加业务逻辑。示例中的素材先上传到项目，服务器地址、令牌、文件路径换成自己的值。
可见组件需要有非零宽高；不可见工具组件...
Change key pair for ec2 instance
...rized_key and delete the old key.
Answer to Shaggie remark:
If you are unable to connect to the instance (e.g. key is corrupted) than use the AWS console to detach the volume (http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-detaching-volume.html) and reattach it to working instance, than...
设置页使用指导 · App Inventor 2 中文网
...
「设置说明」「设置项目可见」「设置项目启用」可在运行中控制项目，例如关闭消息提醒时禁用提醒方式。
这些操作修改当前界面配置，不会保存配置定义；重新启动仍从设计器或初始化积木载入项目。
使用注意
...
REDHAT 6.4 X64下ORACLE 11GR2静默安装 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...ler –record –destinationfile <filename>
2、在命令行窗口运行OUI
./runInstaller –silent –responsefile <filename>
1、查看并编辑oralce 的应答模板
root@redhat mnt]# cd /mnt/oracleinstall/database/response/
[root@redhat response]# ls
db_install.rsp ...
How can I install pip on Windows?
...dly proxy that forwards to the nasty proxy. http://cntlm.sourceforge.net/
Unable to find vcvarsall.bat
Python modules can be partly written in C or C++. Pip tries to compile from source. If you don't have a C/C++ compiler installed and configured, you'll see this cryptic error message.
Error: ...
Can I change the root EBS device of my amazon EC2 instance?
...
I have an instance matching this description, which is unable to boot ("Unable to find root device") after detaching and reattaching the root device. I want to try this answer, but if I don't attach it as /dev/sda1 then AWS refuses to start my instance. Is there some other settin...