![]() ![]() But the seq value differs as there are multiple columns in the key. So, the multiple column key results in multiple rows in the output where id is same as this is actually one key. So if you take the next example - sqlite> CREATE TABLE Test2 (first INTEGER, second INTEGER, FOREIGN KEY (first, second) REFERENCES A(a, b) ON DELETE CASCADE) Readme Changelog Example Installing Versions. ![]() Functional key parts are not permitted in foreign key specifications. Flutter plugin for SQLite, a self-contained, high-reliability, embedded, SQL database engine. You can see the id fields value are 0 and 1 respectively but the seq values are all 0.Īs you may know sqlite allows multiple column names in foreign key statement. For example (col1, col2, col3) specifies a multiple-column index with index keys. You can see there are two foreign keys in table Test and so there are two entries shown in PRAGMA foreign_key_list() output. I know the table Test look like a nightmare, but just ignore the horrible schema for a moment. 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. Id seq table from to on_update on_delete match When you create a table in SQLite, you can also create a foreign key in order to establish a relationship with another table. Take below example executed in sqlite3 cli with header and column option on - CREATE TABLE Test (first INTEGER, second INTEGER, FOREIGN KEY (first) REFERENCES A(a) ON DELETE CASCADE, FOREIGN KEY (second) REFERENCES B(x) ON DELETE CASCADE) So, in the output you got the first two 0s are for id and seq. and import it somewhere in the global place of your app (for example in app.ts ). Id, seq, table, from, to, on_update, on_delete, match For example: sqlite> PRAGMA foreignkeys ON Foreign key constraints are disabled by default (for backwards compatibility), so must be enabled separately for each database. ![]() The following illustrates the syntax of the inner join clause: SELECT a1, a2, b1, b2 FROM A INNER JOIN B on B.f A. Assuming the library is compiled with foreign key constraints enabled, it must still be enabled by the application at runtime, using the PRAGMA foreignkeys command. The output of PRAGMA foreign_key_list() consists of following columns in order - The A table links to the B table using a foreign key column named f. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |