unique
check duplicate mysql row
I have a mysql table that contains field_one, field_two, field_three I want to check if field_one contains a duplicate value (like if it was unique).[详细]
2023-03-10 12:02 分类：问答Index or Unique? What is better MySql
So i have a question. Say you have a table requests, which represent a graph.There are 3 columns in the request table, A, B, time.A -> B At time.So what each row represents is a directed connection f[详细]
2023-03-10 05:34 分类：问答SQL constraint to have one unique value in two columns
I need to assure that a value is unique in two columns (this is not a \"two columns\" index issue). Table A[详细]
2023-03-09 06:28 分类：问答RNAseq中的unigene、scaffold、singleton、Distinct clusters、Distinct singletons、unique gene的区分？
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2023-03-08 23:21 分类：问答How to Generate Unique Number of 8 digits?
I am using this co开发者_如何学运维de to generate a 8 digit unique number. byte[] buffer = Guid.NewGuid().ToByteArray();[详细]
2023-03-08 07:51 分类：问答MySQL doesn't respect UNIQUE and PRIMARY-keys
Hey. To start with, I have to say that this is the first time I have ever tried to write SQL, which means I\'m a n00b. Have some patience, please..[详细]
2023-03-08 01:30 分类：问答Doctrine 2 validation
I have a proble开发者_高级运维m with validation. In Doctrine 1 i used this: if ($model->isValid()) {[详细]
2023-03-07 23:32 分类：问答Unique records query
The following query is showing same user for multiple times, how to make it unique? $query = \'SELECTa.connection_id, a.connect_from, a.connect_to,[详细]
2023-03-07 07:47 分类：问答Python: efficient counting number of unique values of a key in a list of dictionaries
There must be a better way of writing this Python code where I have a list of people (people are dictionaries) and I am trying to find the number of unique values of a certain key (in this case the ke[详细]
2023-03-07 06:05 分类：问答Dealing with PDOException's when DB return an Error Statement
I would like to know how exactly I can deal with the error\'s statements returned by DataBase Drivers available in PDO class.[详细]
2023-03-06 09:08 分类：问答
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