android - sqlite 表中的每一行如何是唯一的。不仅仅是一列行

Question

我有一个 sqlite 表，其中包含姓名和姓氏两列。我希望姓名和姓氏必须不同，而不仅仅是姓名。

我的表代码是

private static final String MAKE_TABLE_NAME_SURNAME = "CREATE TABLE " +
 TABLE_DISEASE_SEMPTOM + "(" + KEY_DSID  " INTEGER PRIMARY KEY AUTOINCREMENT," +
 NAME + " TEXT, " + SURNAME + " TEXT) ";

我无法使用

private static final String MAKE_TABLE_NAME_SURNAME = "CREATE TABLE " +
 TABLE_DISEASE_SEMPTOM + "(" + KEY_DSID  " INTEGER PRIMARY KEY AUTOINCREMENT," +
 NAME + " TEXT UNIQUE, " + SURNAME + " TEXT UNIQUE) ";

因为如果我使用此代码，则无法添加相同的名字但不同的姓氏或相同的姓氏但不同的名称。如果两者相同，怎么能忽略。

Answer 1

我相信以下是您想要的:-

private static final String MAKE_TABLE_NAME_SURNAME = "CREATE TABLE " +
   TABLE_DISEASE_SEMPTOM + "(" + KEY_DSID  " INTEGER PRIMARY KEY AUTOINCREMENT," +
   NAME + " TEXT, " + SURNAME + " TEXT, UNIQUE(" + NAME + "," + SURNAME +")) ";

也就是说，您将名称列和姓氏列的组合定义为 UNIQUE 约束。

例如考虑:-

DROP TABLE IF EXISTS TABLE_DISEASE_SEMPTOM;
CREATE TABLE IF NOT EXISTS TABLE_DISEASE_SEMPTOM (KEY_DSID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, SURNAME TEXT, UNIQUE(NAME,SURNAME));
INSERT INTO TABLE_DISEASE_SEMPTOM (NAME,SURNAME) VALUES('Fred','Bloggs'),('Fred','Smith'),('Mary','Smith'),('Jane','Doe');
INSERT OR IGNORE INTO TABLE_DISEASE_SEMPTOM (NAME,SURNAME) VALUES('Fred','Bloggs'); -- will not be inserted as duplicate
SELECT * FROM TABLE_DISEASE_SEMPTOM;

前 4 个插入有效，最后一个(单独)被忽略(因为它是重复的)。 因此最终查询产生:-

日志是:-

INSERT INTO TABLE_DISEASE_SEMPTOM (NAME,SURNAME) VALUES('Fred','Bloggs'),('Fred','Smith'),('Mary','Smith'),('Jane','Doe')
> Affected rows: 4
> Time: 0.117s


INSERT OR IGNORE INTO TABLE_DISEASE_SEMPTOM (NAME,SURNAME) VALUES('Fred','Bloggs')
> Affected rows: 0
> Time: 0.117s

即最后一次插入没有插入任何行