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Display names of all constraints for a table in Oracle SQL
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You need to query the data dictionary, specifically the USER_CONS_COLUMNS view to see the table columns and corresponding constraints:
SELECT *
FROM user_cons_columns
WHERE table_name = '<your table name>';
FYI, unless you specifically created your table with ...
Why does the is operator return false when given null?
It seems to me that the is operator is a bit inconsistent.
7 Answers
7
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Make sure only a single instance of a program is running
...ode version is available singleton.py. Please file bugs here.
You can install tend using one of the following methods:
easy_install tendo
pip install tendo
manually by getting it from http://pypi.python.org/pypi/tendo
sh...
How to reuse an ostringstream?
...000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 47.1084 7.58816C47.4091 7.46349 47.7169 7.36433 48.0099 7.26993C48.9099 6.97997 49.672 6.73443 49.672 5.93063C49.672 5.22043 48.9832 4.61182 48.1414 4.61182C47.4335 4.61182 46.7256 4.91628 46.0943 5.50789C45.7307 4.9328 4...
Rails migrations: self.up and self.down versus change
... For example, in your case what is the reverse operation of add_column to call when you rollback? Of course it's remove_column. What is the inverse of create_table? It's drop_table. So in these cases rails know how to rollback and define a down method is superfluous (you can see in the documentation...
What are some (concrete) use-cases for metaclasses?
...a couple functions I found that I was able to increment the figure count, call draw manually, etc, but I needed to do these before and after every plotting call. So to create both an interactive plotting wrapper and an offscreen plotting wrapper, I found it was more efficient to do this via metacla...
新浪是如何分析处理32亿条实时日志的？ - 更多技术 - 清泛网 - 专注C/C++及内核技术
新浪是如何分析处理32亿条实时日志的？【编者的话】我从2014年初入职新浪后就开始接触实时日志分析相关的技术，主要是ELK（Elasticsearch、Logstash、Kibana），当时是学习+ELK优...【编者的话】我从2014年初入职新浪后就开始接触实...
Set object property using reflection
..., "Value");
This will throw an exception if obj doesn't have a property called Name, or it can't be set.
Another approach is to get the metadata for the property, and then set it. This will allow you to check for the existence of the property, and verify that it can be set:
using System.Reflecti...
How to use sed to replace only the first occurrence in a file?
...lude directive before any existing #includes. For this sort of task, I normally use a small bash script with sed to re-write the file.
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Advantages to Using Private Static Methods
When creating a class that has internal private methods, usually to reduce code duplication, that don't require the use of any instance fields, are there performance or memory advantages to declaring the method as static?
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