Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
153 views
in Technique[技术] by (71.8m points)

android - SQLite Foreign Key

I'm following the instructions from the SQLite documentation at http://www.sqlite.org/foreignkeys.html however my attempt to add a foreign key is failing. Here are my create statements:

CREATE TABLE 
    checklist (
        _id INTEGER PRIMARY KEY AUTOINCREMENT, 
        checklist_title TEXT,
        description TEXT,
        created_on INTEGER, 
        modified_on INTEGER
    );

CREATE TABLE 
    item (
        _id INTEGER PRIMARY KEY AUTOINCREMENT,  
        FOREIGN KEY(checklist_id) REFERENCES checklist(_id), 
        item_text TEXT, item_hint TEXT, 
        item_order INTEGER, 
        created_on INTEGER, 
        modified_on INTEGER
    );

The first table is made fine. The error occurs in the second statement. I have tried both with wrapping the two queries in a transaction and without. Here is the error:

unknown column "checklist_id" in foreign key definition (code 1): , while compiling: CREATE TABLE item (_id INTEGER PRIMARY KEY AUTOINCREMENT, FOREIGN KEY(checklist_id) REFERENCES checklist(_id), item_text TEXT, item_hint TEXT, item_order INTEGER, created_on INTEGER, modified_on INTEGER)

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You still have to create the column checklist_id INTEGER before you add it as a Foreign key.

So it would be:

CREATE TABLE 
    checklist (
        _id INTEGER PRIMARY KEY AUTOINCREMENT, 
        checklist_title TEXT,
        description TEXT,
        created_on INTEGER, 
        modified_on INTEGER
    );

CREATE TABLE 
    item (
        _id INTEGER PRIMARY KEY AUTOINCREMENT,  
        checklist_id INTEGER,
        item_text TEXT, 
        item_hint TEXT, 
        item_order INTEGER, 
        created_on INTEGER, 
        modified_on INTEGER,
        FOREIGN KEY(checklist_id) REFERENCES checklist(_id)
    );

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...