SQLite 外键

SQLite Foreign Key(SQLite 外键)

问题描述

我正在按照 http://www.sqlite.org/foreignkeys.html 但是我尝试添加外键失败了.这是我的创建语句:

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
    );

第一张桌子做得很好.错误发生在第二个语句中.我已经尝试过将两个查询包装在一个事务中，也没有.这是错误:

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:

外键定义(代码 1)中的未知列checklist_id":，编译时: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)

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)

推荐答案

在将其添加为外键之前，您仍然需要创建列 checklist_id INTEGER.

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

原来是这样:

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)
    );

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