我在android上使用sqlite,当我将文本插入整数列时,我没有收到任何错误,外键约束也没有';行不通
下面是代码:我正在创建两个表,即:教师和凭证。我希望凭证ID列引用教师ID列。还要遵守数据类型约束。即,我不能在文本列中插入整数,反之亦然 请帮帮我已经两天了,我受够了:我在android上使用sqlite,当我将文本插入整数列时,我没有收到任何错误,外键约束也没有';行不通,android,sqlite,Android,Sqlite,下面是代码:我正在创建两个表,即:教师和凭证。我希望凭证ID列引用教师ID列。还要遵守数据类型约束。即,我不能在文本列中插入整数,反之亦然 请帮帮我已经两天了,我受够了: public class WinnersTeachersDbHelper extends SQLiteOpenHelper { // If you change the database schema, you must increment the database version. private static final
public class WinnersTeachersDbHelper extends SQLiteOpenHelper {
// If you change the database schema, you must increment the database version.
private static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "winnersteachersbanana.db";
public WinnersTeachersDbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
// Create a table to hold teachers details.
final String SQL_CREATE_TEACHERS_TABLE = "CREATE TABLE " + Teachers.TABLE_NAME + " (" +
Teachers._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
Teachers.COLUMN_FULL_NAME + " TEXT NOT NULL, " +
Teachers.COLUMN_MOBILE_NUMBER + " TEXT NOT NULL, " +
" UNIQUE (" + Teachers.COLUMN_MOBILE_NUMBER + ") ON CONFLICT REPLACE);";
// Create a table to hold credentials details.
final String SQL_CREATE_CREDENTIALS_TABLE = "CREATE TABLE " + Credentials.TABLE_NAME + " (" +
Credentials._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
Credentials.COLUMN_TEACHER_ID + " INTEGER NOT NULL, " +
Credentials.COLUMN_USERNAME + " TEXT NOT NULL, " +
Credentials.COLUMN_PASSWORD + " TEXT NOT NULL, " +
// Set up the teacherId column as a foreign key to teachers table.
" FOREIGN KEY (" + Credentials.COLUMN_TEACHER_ID + ") REFERENCES " +
Teachers.TABLE_NAME + " (" + Teachers._ID + "), " +
" UNIQUE (" + Credentials.COLUMN_TEACHER_ID + ") ON CONFLICT REPLACE);";
sqLiteDatabase.execSQL(SQL_CREATE_TEACHERS_TABLE);
sqLiteDatabase.execSQL(SQL_CREATE_CREDENTIALS_TABLE);
}
SQLite使用;您必须使用单独的约束强制列类型:
CREATE TABLE ... (
...,
FullName TEXT NOT NULL CHECK(typeof(FullName) = 'text'),
...
);
SQLite使用;您必须使用单独的约束强制列类型:
CREATE TABLE ... (
...,
FullName TEXT NOT NULL CHECK(typeof(FullName) = 'text'),
...
);