unique-constraint

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Unique constraint violation during insert: why? (Oracle)

I\'m trying to create a new row in a table.There are two constraints on the table -- one is on the key field (DB_ID), the other constrains a value to be one of several the the field ENV.When I do an i[详细]

2023-04-07 19:13 分类：问答
Unique combination of fields in SQLite?

I\'m trying to populate a new SQLite database with rows based o开发者_如何学Cn a set of data, but I\'m having trouble with avoiding duplicate rows.I could accomplish this in Python, but there certainl[详细]

2023-04-04 10:37 分类：问答
React on UniqueKeyViolation in SQLAlchemy

I have 2 Tables in SQLAlchemy (using declerative_base()) that are joined via a seperate Table relationship[详细]

2023-03-29 05:00 分类：问答
ORA-00001: unique constraint (DEV.X_PK) violated

I have a java code that sends data to a web service, and a portlet that uses that data. Data sent by java agent gets placed in TMP table, and merge procedure merges it into MAIN table used by portle[详细]

2023-03-28 04:46 分类：问答
Given a too long varchar column in MySQL: Is it recommended to hash the string and make the hash-column unique?

I have a varchar column which is too big to make it unique. Is it Ok to hash the value of the column and store the hash in an other varchar column which is unique? Are their sideeffects to this approa[详细]

2023-03-27 18:14 分类：问答
MySQL unique composite constraint not working

I\'ve created a unique index like this: ALTER TABLE items ADD UNIQUE INDEX uni_item (warehouse_id, width, height, depth, weight);[详细]

2023-03-26 16:42 分类：问答
Why is there no unique constraint in Google Appengine?

I have seen many articles and questions about how to implement a unique constraint in appengine, but I actually didn\'t found any explanation about why this feature is not presen开发者_开发知识库t.[详细]

2023-03-26 14:09 分类：问答
Does VoltDB support unique indexes?

Our schema has a USER table... USER( userId, firstname, lastname, email) and we want to ensu开发者_开发百科re all user\'s have unique email addresses. Is it possible to create a unique index in Vo[详细]

2023-03-25 18:32 分类：问答
Nullable natural id?

Can I add a unique constraint 开发者_JS百科to natural id fields, so that only non-null values should be unique, but allow for multiple nulls?Yes. It sounds like this is the default behavior, according[详细]

2023-03-25 18:04 分类：问答
Creating a constraint in Oracle that depends on other columns

Please consider the following table structure on Oracle: create table DOCS ( DOC_NONUMBER not null, DOC_TYPE VARCHAR2(5) not null,[详细]

2023-03-25 00:50 分类：问答