![]() ![]() ABL triggers do not cover SQL operations. From ABL, someone can programmatically disable triggers using the DISABLE TRIGGERS statement. ![]() Then we will not know that this code has been changed. However, SQLite allows NULL values in the PRIMARY KEY column except that a column is INTEGER PRIMARY KEY column or the table is a WITHOUT. Based on the SQL standard, PRIMARY KEY should always imply NOT NULL. The ABL code of the trigger can be illegally replaced by someone. Unlike other constraints such as PRIMARY KEY and CHECK, you can only define NOT NULL constraints at the column level, not the table level. The ABL trigger is not part of the database and must be stored separately in the file system.Ģ. Right?īut it is inconvenient for database exploitation:ġ. Suppose the use of FK is not possible in OpenEdge at the SQL level.Īt the OpenEdge ABL level to implement something like referential integrity I have to write an ABL procedure for the trigger to delete, create, etc. Am I wrong again? If I'm wrong, what is this article for? It is a bug? Where it is a bug, in the article or in my code above? CREATE TABLE Test (first INTEGER, second INTEGER, FOREIGN KEY. Take below example executed in sqlite3 cli with header and column option on. So, in the output you got the first two 0 s are for id and seq. id, seq, table, from, to, onupdate, ondelete, match. /SQL-command-to-add-a-FOREIGN-KEY-constraint-to-an-existing-table-fails-with-the-error-7545įrom this article I conclude that it is still possible at the SQL level. The output of PRAGMA foreignkeylist () consists of following columns in order. There also use the PUB scheme in the example. Judging by this article, this is possible, but only need to be sure that the table columns chosen as primary or foreign key do not accept NULL values by making them mandatory. I wanna to create a foreign key between Order.Cust_Num and Customer.Cust_Num fields. Both fields have the MANDATORY option:ĪDD FIELD "Cust_Num" OF "Customer" AS characterĪDD FIELD "Name" OF "Customer" AS characterĪDD FIELD "Order_Num" OF "Order" AS characterĪDD FIELD "Cust_Num" OF "Order" AS character These are the data definitions for my two test tables. Make sure that the table columns chosen as primary or foreign key do not accept NULL values by making them mandatory. SQL Error : No matching key defined for the referenced table (7545)Ĭolumns defining a primary or foreign key must not accept the NULL value. Enable Foreign Key Support The first thing we should do is to enable foreign key support (if it hasn’t already been done). ![]() This article provides an example of creating a foreign key when creating a table in SQLite. I do it in the Dbeaver. But I got the following error: When you create a table in SQLite, you can also create a foreign key in order to establish a relationship with another table. I am trying to add a foreign key to my existing table using by SQL command.ĪLTER TABLE PUB."Order" ADD CONSTRAINT ORDER_CUSTOMER_FK FOREIGN KEY ("Cust_Num") REFERENCES PUB."Customer"("Cust_Num") ![]()
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