sqlite - 如何使用 SQLite 批量插入？

Question

如何使用 SQLite 进行批量插入？

我查了一下，好像我用 select 语句做了一个插入。我用谷歌搜索，查看了示例，它们看起来都像是将数据从一个表复制到另一个表，或者与 SQLite 不兼容。我想做类似的事情

"INSERT INTO user_msg_media (recipientId, mediaId, catagory, current_media_date) " +
"VALUES(@mediaId, @catagory, @current_media_date)";
where the value of recipientId is the watcher from each of
"SELECT watcher FROM userwatch WHERE watched=@watched";

我尝试了下面的代码，但出现错误“SQLite 错误没有这样的列:watcher”

        command.CommandText =
            "CREATE TABLE if not exists user_msg_media( " +
            "msgId        INTEGER PRIMARY KEY, " +
            "recipientId  INTEGER, " +
            "mediaId      INTEGER, " +
            "catagory     INTEGER, " +
            "current_date DATE);";
        command.ExecuteNonQuery();

        //user media
        command.CommandText =
            "CREATE TABLE if not exists user_watch( " +
            "indx INTEGER PRIMARY KEY, " +
            "watcher INTEGER, " +
            "watched INTEGER);";
        command.ExecuteNonQuery();
        //...

    command.CommandText = "SELECT watcher FROM user_watch WHERE watched=:watched;";
    command.Parameters.Add(":watched", DbType.Int64).Value = 1;
    command.ExecuteNonQuery(); //is ok

    command.CommandText =
        "INSERT INTO user_msg_media (recipientId, mediaId, catagory, current_media_date) " +
        "SELECT watcher, :mediaId, :category, :current_media_date" +
        "FROM user_watch WHERE watched=:watched;";
    command.Parameters.Add(":mediaId", DbType.Int64).Value = 0;
    command.Parameters.Add(":category", DbType.Int64).Value = 0;
    command.Parameters.Add(":current_media_date", DbType.Int64).Value = 0;
    command.Parameters.Add(":watched", DbType.Int64).Value = 1;
    command.ExecuteNonQuery();

Answer 1

我编写了一个类来帮助简化 SQLite 中的批量插入。希望对您有所帮助:

http://procbits.com/2009/09/08/sqlite-bulk-insert/

-日本