referential-integrity

问题 As in this question, I've been reading PoEAA and wondering if it's possible to defer referential integrity checks until commit in MySQL. I've run into this problem when wanting to insert a bunch of products and related products in the same commit. Even within a transaction, I get constraint errors when I try to insert into the related_products join table. If it helps, I'm using PHP PDO for database connections. I'd appreciate any help you could offer. 回答1: Looks like my answer is here... Like

问题 I am creating an application that will handle and record when a student gets advised by a faculty member at a university and I need an effective way to structure the tables. My problem is coming from a lack of referential integrity, caused by the inability to create a foreign key that will reference a STUDENT on only part of a composite key in ADVISE_HIST which is (STUDENT_ID,DATE_ADVISED) here are some of the tables create table STUDENT( LNAME varchar(50), FNAME varchar(50), ID char(9)

问题 Just curious, if I have this table: CREATE TABLE "post" ( "id" SERIAL, "revision" INTEGER NOT NULL DEFAULT 0, "summary" CHARACTER VARYING NOT NULL, "description" TEXT NOT NULL, "user_id" INTEGER NOT NULL REFERENCES "user" ("id") MATCH FULL ON UPDATE CASCADE ON DELETE RESTRICT, "post_type_id" INTEGER NOT NULL REFERENCES "post_type" ("id") MATCH FULL ON UPDATE CASCADE ON DELETE RESTRICT, "ctime" TIMESTAMP WITH TIME ZONE DEFAULT NOW(), PRIMARY KEY("id", "revision") ); to store posts, and this

问题 I need a query (INFORMATION_SCHEMA) which will for given schema and table name show me all table columns with following attributes (what key type it is: PK=>Primary Key, UQ=>Unique Key, FK=>Foreign Key, what is key name, and if it is Foreign Key what schema.table.column is referenced): COLUMN_NAME | DATA_TYPE | KEY_TYPE | KEY_NAME | REFERENCED ============+===========+==========+=============+======================== empid | int | PK | PRIMARY | empname | varchar | UQ | uq_empname | empactive

问题 We are planning on introducing simple Audit Trail in our database using triggers and separate history table for each table that requires auditing. For example consider table StudentScore, it has few foreign keys (eg. StudentID, CourseID) linking it to corresponding parent tables (Student & Course). Table StudentScore ( StudentScoreID, -- PK StudentID ref Student(StudentID), -- FK to Student CourseID ref Course(CourseID), -- FK to Course ) If StudentScore requires auditing, we are planning to

问题 I would like to know if it's possible to write a migration instead of of the following raw SQL statement: execute <<-SQL ALTER TABLE records ADD CONSTRAINT fk_records_domains FOREIGN KEY (domain_id) REFERENCES domains(id) ON DELETE CASCADE SQL I would like avoid using sql because i'm getting problems when trying to rollback such migration: execute <<-SQL ALTER TABLE records DROP FOREIGN KEY fk_records_categories SQL rake db:rollback == Integrity: reverting ====================================

问题 How to create a function that compares card_id with allowed_cards array elements? If it's in this array, column status must be updated to TRUE . CREATE TABLE client_1 ( id bigint NOT NULL, "time" timestamp without time zone DEFAULT now(), status boolean, card_id character varying(10), CONSTRAINT client_1_pkey PRIMARY KEY (id) ); CREATE TABLE allowed_cards ( allowed_cards character varying(10)[] ); INSERT INTO allowed_cards VALUES ('{DD3234,FF2342}'); 回答1: Enforce valid card_id at all times

问题 Is there any way to add constraints or foreign keys the way I would in a database? E.g. making sure a field is unique, a field is always > 0, that customer_id in the orders table always has a match in customer_id in the customer table, etc? 来源： https://stackoverflow.com/questions/32353732/python-pandas-can-i-add-constraints-like-i-would-in-a-database

问题 First, thanks for taking the time to read this. I'm having some difficulties with trying to update a database using EF. I've used this same approach before on another project, so I'm thinking the issue is perhaps in the database, but I'm just not seeing it. The database is a legacy db in SQL 2005, and the naming convention has a lot to be desired, therefore I've been mapping the inconsistent names to something more consistent via the HasColumnName method: as in. modelBuilder.Entity<Case

问题 I'm working with Entity Framework 6 Code First and Fluent API. I have a one to many relationship between Visit and VisitPage (1 Visit has many VisitPage objects). This is the simplified version of the POCO classes: Visit : Id (identity), UrlReferrer, Pages. VisitPage : Id (identity), Name, Visit, VisitId First, I create a Visit object and add a VisitPage object to it. Then, I insert them into the DB. Until this point everything works OK. Observation: VisitId property in VisitPage is