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Tag: constraints

Enforce 2 unique constraints on upserts in Postgres

I have a table where I save contacts data I add data to this table from several sources. Some sources have Linkedin profiles data about people, other sources have email data. Sometimes the full names are not equal, even if they refer to the same person. And I want to do upserts to not have duplicated data. For now I’m

Create CHECK constraint SQL

I hope you can help me. I would like to create a check constraint that ensure the column INKOOPBEDRAG has to be higher than PRIJS_PER_D. In the table INKOOPOVEREENKOMST.[BARCODE] it is a FK to ARTIKEL.[BARCODE]. I have created the following CHECK constraint, but I get an error: Answer I solved this using the following: Then I added a Constraint as

Passing parameters for a constraint function

I have the following table that joins driver and truck tables in order to assign trucks to drivers. I need to constraint entries that belong to the same driver on the same day, and DO NOT include the same truck code. It was suggested to create a boolean function to pass along dateval, truckval and driverval, and returns the following.

DROP Constraint without knowing the name

I know there are a lot of references out there for what I am going to mention. I am rather sharing something I feel should be very useful and consolidating in one place – Q&A-style. I have struggled earlier finding this for different constraints on different time. The following constraints are commonly used: Primary key Constraint Foreign key Constraint Unique

Can’t enable a foreign key in ORACLE SQL

So I have a disabled foreign key (Manager_ID in the table Employees) and I wanted to enable it, but I get this error: ORA-02298: cannot validate (my_username.EMP_MANAGER_FK) – parent keys not found And this is the code: Here’s how the table was created: Answer There are values in the column that are invalid from the foreign key’s perspective. Assuming that

non UNIQUE constraints

So, I got in this situation: I create a table (let say model_a), in this table I have 2 cols (let say col1 and col2). I need a constraint that satisfy this reality: It’s not UNIQUE constraint, you can duplicate the first row. The only one time this constraint active is col1 is the same but col2 is different. Need

Add check constraint related to other column

My table structure is as below I want to add a constraint to this table where only if IsActive=1, GoSequence value can be change. If IsActive=0, GoSequence stays 0. Any help is appreciated. Thanks! Answer Probably the simplest way of expressing that is that either GoSequence must be 0 or IsActive must be 1. So your constraint could look like