check-constraints

问题 Suppose, I have the following table: CREATE TABLE "user" ( id BIGINT PRIMARY KEY NOT NULL, phone1 VARCHAR, phone2 VARCHAR ); And I need to implement the following limitation: all phone numbers (if any) in table must be unique. i.e database should not allow any of the following situations: id | phone1 | phone2 1 | 111 | 111 id | phone1 | phone2 1 | 111 | NULL 2 | 111 | NULL id | phone1 | phone2 1 | 111 | NULL 2 | NULL | 111 I know how to implement constraints for first two examples, but I'm

问题 Suppose, I have the following table: CREATE TABLE "user" ( id BIGINT PRIMARY KEY NOT NULL, phone1 VARCHAR, phone2 VARCHAR ); And I need to implement the following limitation: all phone numbers (if any) in table must be unique. i.e database should not allow any of the following situations: id | phone1 | phone2 1 | 111 | 111 id | phone1 | phone2 1 | 111 | NULL 2 | 111 | NULL id | phone1 | phone2 1 | 111 | NULL 2 | NULL | 111 I know how to implement constraints for first two examples, but I'm

问题 I would like to create a more specific error message for Postgres CHECK IN violations. So for example a violation of the following CHECK constraint on a column: management_zone varchar(15) NOT NULL CHECK (management_zone IN ('Marine', 'Terrestrial') ), should return a custom error message such as ie.: "Hint: Check spelling. Only allowed inputs are: 'Marine', 'Terrestrial'. The best solution I have seen so far solves it by using the error message as the name of the check constraint, ie ADD

问题 I would like to create a more specific error message for Postgres CHECK IN violations. So for example a violation of the following CHECK constraint on a column: management_zone varchar(15) NOT NULL CHECK (management_zone IN ('Marine', 'Terrestrial') ), should return a custom error message such as ie.: "Hint: Check spelling. Only allowed inputs are: 'Marine', 'Terrestrial'. The best solution I have seen so far solves it by using the error message as the name of the check constraint, ie ADD

问题 i'v been learning SQL for the last week but I am unsure how to correctly add a case statement within a check constraint. Can anybody give me any pointers? I have the following grade table: CREATE TABLE Grade ( salary_grade char(1) NOT NULL CHECK (salary_grade = UPPER(salary_grade)), CONSTRAINT ck_grade_scale CHECK( CASE WHEN salary_grade = '[A-D]' THEN salary_scale = 'S1' WHEN salary_grade = '[D-G]' THEN salary_scale = 'S2' END) salary_scale char(2) DEFAULT 'S1' NOT NULL, CONSTRAINT pk_grade

问题 I have a check constraint on a table in my DB. My understanding of a check is it sets a logical condition that must be true for records in a table. USE [myDB] GO ALTER TABLE [dbo].[myTable] WITH CHECK ADD CONSTRAINT [oneProgramPerTest] CHECK (([dbo].[howManyProgPerTest]([TestId])<(2))) GO ALTER TABLE [dbo].[myTable] CHECK CONSTRAINT [oneProgramPerTest] GO But I am able to do an update to the table that breaks the constraint. After the update, this query returns 9 records: select COUNT (*)

问题 I am trying to set a constraint where user are only allowed to input 11 digits into the Number Data Type (Phone Number). I've tried alter table "booyeah" add constraint "booyeah_CC1" check ( LENGTH("PHONE_NO") = 11) / and alter table "booyeah" add constraint "booyeah_CC1" check ( PRECISION("PHONE_NO") = 11) / but got an error. For the first one, I kept getting error because it's not detecting the character length, while the second one, gave me an invalid identifier. Thanks for the help! 回答1:

问题 My query : INSERT into PriceListRows (PriceListChapterId,[No]) SELECT TOP 250 100943 ,N'2' FROM #AnyTable This query works fine and the following exception raises as desired: The INSERT statement conflicted with the CHECK constraint "CK_PriceListRows_RowNo_Is_Not_Unqiue_In_PriceList". The conflict occurred in database "TadkarWeb", table "dbo.PriceListRows". but with changing SELECT TOP 250 to SELECT TOP 251 (yes! just changing 250 to 251!) the query runs successfully without any check

问题 I am trying to create a table where the values in one column can't be greater than the next column over. For example, I am creating the following table. CREATE TABLE Price ( PriceID INT PRIMARY KEY IDENTITY (1,1), OriginalPrice FLOAT NOT NULL, CurrentPrice FLOAT NOT NULL, Discount FLOAT, ShippingCost FLOAT NOT NULL, Tax FLOAT NOT NULL); And Current Price cannot be greater than OriginalPrice. So what I tried doing was CurrentPrice FLOAT CHECK (CurrentPrice <= OriginalPrice) NOT NULL, But this

问题 This question already has answers here : CHECK constraint in MySQL is not working (8 answers) Closed 11 months ago . check constraint won't work CREATE TABLE IF NOT EXISTS supervisor ( sup_id INT(3) NOT NULL, sup_name VARCHAR(30) NOT NULL, gen VARCHAR(1) NOT NULL CHECK (gen='M' or gen='F'), dep_id INT(4), PRIMARY KEY (sup_id), INDEX (dep_id), FOREIGN KEY (dep_id) REFERENCES department(dep_id) ON UPDATE CASCADE ON DELETE RESTRICT ); i also tried: CONSTRAINT chk_supervisor_gen CHECK ('M' or 'F'