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Questions tagged [check-constraints]

CHECK constraints enforce domain integrity by limiting the values that are accepted by one or more columns.

SQL CHECK constraints enforce domain integrity by limiting the values that are accepted by one or more columns.

You can create a CHECK constraint with any logical (Boolean) expression that returns TRUE or FALSE based on the logical operators. For example, the range of values for a salary column can be limited by creating a CHECK constraint that allows for only data that ranges from $15,000 through $100,000. This prevents salaries from being entered beyond the regular salary range. The logical expression would be the following: salary >= 15000 AND salary <= 100000.

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SQL constraint for a variable to start with a letter followd by numbers

I'm a beginner on oracle apex and im trying to implement a constraint that only allows variables in a column that start with a certain letter ('P') and are followed by numeric digits. Any help?
Stavros Kasapi
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Adding a user-defined prefix for a column in SQL Server

In my patient table, I want all the patient IDs to start with the 'PT' prefix. For example, PT01, PT02, ... My code is: CREATE TABLE patient ( p_id varchar(10) PRIMARY KEY CHECK(p_id in('PT%')), pname varchar(22) ) It does not work... any…
Hisham Nawzer
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SQL - CONSTRAINT not working, still able to submit values outside constraint

OBJECTIVE CREATE a TABLE for AccountsReceivables with associated parameters (e.g invoice_id, customer_id, etc.). Ensure that CONSTRAINTS are added to business_unit and invoice_terms to help standardize user input APPROACH/SCHEMA CUSTOMER…
jonplaca
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Constrains using DATE

I'm trying to create a constrain to check the record is no greater than 2016. Here is the record in my database Here is my query: ALTER TABLE SIGHTINGS ADD CONSTRAINT CK_SIGHTING_DATE CHECK (SIGHTING_DATE <=TO_DATE('01-JAN-16')); But I got…
Sean Li
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Check Constraint Which Uses A Custom Function

I want to let user to enter, only one entry of data with specific ReqNo, that it's Type is equal 'SS'. There are two issue: I Receive following error: Msg 4145, Level 15, State 1, Line 21 An expression of non-boolean type specified in a context…
Hassan Faghihi
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What does 'indexes' do in sql query

I come to know that this is used to speed up data retrieval..I like to know more about it .Thanks .
arifCoder
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Mysql check Constraint does not work

I'm going to use mysql constraints to prevent inserting numbers less than zero. I found this query from W3schools. CREATE TABLE Persons ( P_Id int NOT NULL, LastName varchar(255) NOT NULL, FirstName varchar(255), Address varchar(255), City…
Vahid Najafi
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Is it a good practice to use CHECK constraints to validate data during an INSERT statement

Which way is considered better to validate the input of data before inserting it into a table, use CHECK constraints or use if statement? Are there better ways to validate it? 1) DECLARE INVALID_DATE EXCEPTION; ... -- Check if date is valid IF…
Roni Castro
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Check Constraint in Oracle SQL Developer

need your help I have a table in Oracle SQL Developer of this kind: Issue ID|Subscriber_ID|Book_ID| Taken |Returned --+-------------+-------+--------+-------- 1 | 1 | 2 |01-06-16|05-06-16 2 | 3 | 5 |07-05-16| (null) 3 |…
JGDger
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sqlite.net code first: add check constraint

Given an sqlite database, and a code first approach, how can I add a check constraint to a table? I can't use sql, so is there an attribute or so I can use, like [PrimaryKey]? I'm hoping for something like public class XXX { [PrimaryKey,…
Volker
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Find error-ed column name in Oracle not null constraint

I have a table with multiple NOT NULL columns. When I insert data with NULL value in NOT NULL columns, NOT NULL constraint error ORA-01400 is raised, but Column name in error message is blank. ORA-01400: cannot insert NULL into () Why I cannot see…
Maulik
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Ensuring a date entered is at least 3 years greater than another

I am trying to make a constraint to ensure that the finishdate is at least 3 years greater than the startdate. I have had a look around but really do not know where to start? Would i need to use a dateadd function? Thanks
user5572394
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Only allow current date/time on SQL Server insertion

I need a way to enforce a single value only within an inserted field, more precisely a DateTime field, that should always be set to the current date/time at insertion. I am working on a university exercise and they want all the constraints to be…
Louis M.
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Case on constraint Oracle

We're learning about databases and for our case the database is Oracle, in class we we're asked to create a constraint based on the information of another field on the table, and the constraint should be build with a case inside, despite of a large…
Leonardo Forero
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SQL Constraint Verification Function

I want to check during a request if the constraint are respected, if they are not instead of sending an ERROR message, simply return FALSE. How would I do that? Example of TABLE I'm using: CREATE TABLE tree ( name VARCHAR(64) UNIQUE PRIMARY…
sourpet
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