使用SQLiteDatabase.execSQL执行多个语句

Question

我遵循了使用Android构建数据库的标准教程.我创建了一个名为DbHelper的类,它扩展了SQLiteOpenHelper.我已重写创建处理程序以执行字符串.

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(DbDefinitions.DB_CREATE);
}

DbDefinitions.DB_CREATE是我创建的静态String.

public static final String TABLE_MESSAGES = "messages";
public static final String TABLE_FRIENDS = "friends";

public static final String STATE_OK = "STATE_OK";

public static final String DB_CREATE = 
    "create table " + TABLE_MESSAGES + " (_id integer primary key, user_id integer not null, created_on integer, subject text not null, summary text not null, messagetext text null, read integer not null, status text not null default '" + STATE_OK + "'); " +
    "create table " + TABLE_FRIENDS + " (_id integer primary key, user_id integer not null, friend_id integer not null, created_on integer, status text not null default '" + STATE_OK + "');";

我想使用1 String来执行多个SQL语句.我怎么能这样做,因为SQLiteDatabase.execSQL只允许1个语句？

Answer 1

使用Android附带的标准方法是不可能的.因此,如果要执行多个SQL语句批处理,则必须创建自己的实用程序才能执行此操作.例如,你可以这样:

public void executeBatchSql(String sql){
    // use something like StringTokenizer to separate sql statements
    for each sql statement{
        database.execSQL(oneStatement);
    }
}

虽然,我做的是这样的:

String sql1 = "create bla bla bla;";
String sql2 = "create foo bar;";
String[] statements = new String[]{sql1, sql2};

// then
for(String sql : statements){
    database.execSQL(sql);
}

Answer 2

好吧,在我的情况下,我从一个文件中删除查询,我保存为资产这是我使用的解决方案+ -

String script = readAsset(CREATE_SCRIPT);//readAsset is a method i use to get the file contents
try {
     String[] queries = script.split(";");
 for(String query : queries){
        db.execSQL(query);
     }
 } catch (Exception e) {
    .....

编辑

在我的例子中,查询是我完全控制的简单插入查询.但是,有关";"的查询的问题已经提出 在他们里面.

@TWiStErRob建议使用

script.split(";$");// $ meaning end of line. You will need to use RegexOption.MULTILINE for this to work

要么

script.split(";\n");// but you will need to ensure that each query is on a different line