【发布时间】：2018-11-18 02:20:10
【问题描述】：
我查看了太多教程，无法列出，它们都推荐相同的东西。但是，他们并没有帮助解决我的问题。
我试图在我的项目中包含一个 SQLite DB，并且在为 PC、MAC 和 Linux Standalone 构建（在 Windows 机器上测试）时，该数据库按预期工作。在 Android 设备上进行测试时，出现以下错误。
E/Unity: ArgumentException: Invalid ConnectionString format for parameter "/storage/emulated/0/Android/data/com.tbltools.tbl_project/files/TBLDatabase.db"
at Mono.Data.Sqlite.SqliteConnection.ParseConnectionString (System.String connectionString) [0x00000] in <filename unknown>:0
at Mono.Data.Sqlite.SqliteConnection.Open () [0x00000] in <filename unknown>:0
at UIHandler+<RequestAllStudentNames>c__Iterator2.MoveNext () [0x00000] in <filename unknown>:0
at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in <filename unknown>:0
我认为对 connectionString 进行修改应该很简单，但这并没有解决我的问题。这是我目前所拥有的：
if (Application.platform != RuntimePlatform.Android)
{
// The name of the db.
tblDatabase = "URI=file:" + Application.dataPath + "/TBLDatabase.db"; //returns the complete path to database file exist.
}
else
{
tblDatabase = Application.persistentDataPath + "/TBLDatabase.db";
if (!File.Exists(tblDatabase))
{
// if it doesn't ->
Debug.LogWarning("File \"" + tblDatabase + "\" does not exist. Attempting to create from \"" + Application.dataPath + "!/assets/" + "TBLDatabase.db");
// open StreamingAssets directory and load the db ->
// #if UNITY_ANDROID
var loadDb = new WWW("jar:file://" + Application.dataPath + "!/assets/" + "TBLDatabase.db"); // this is the path to your StreamingAssets in android
while (!loadDb.isDone) { } // CAREFUL here, for safety reasons you shouldn't let this while loop unattended, place a timer and error check
// then save to Application.persistentDataPath
File.WriteAllBytes(tblDatabase, loadDb.bytes);
}
}
//open db connection
var connection = new SqliteConnection(tblDatabase);
connection.Open();
var command = connection.CreateCommand();
我使用了 adb shell 并从我的 Android 设备中提取了数据库，一切都符合预期（数据库确实存在并且它不是空的）。
我相信我拥有所有相关的 dll 文件，但如果有人能给我一些指导，我将不胜感激。
**************************************************** ****编辑********************************************* *
此后，我根据给出的建议进行了以下更改。
我现在正在调用以下方法来启动我的连接并处理数据库请求StartCoroutine(RunDbCode(dbFileName, jsonStudentID, jsonIndiNames, jsonIndiStudentNumbers));
那我有以下方法：
IEnumerator RunDbCode(string fileName, List jsonStudentID, List jsonIndiNames, List jsonIndiStudentNumbers)
{
//Where to copy the db to
string dbDestination = Path.Combine(Application.persistentDataPath, "data");
dbDestination = Path.Combine(dbDestination, fileName);
//Check if the File do not exist then copy it
if (!File.Exists(dbDestination))
{
//Where the db file is at
string dbStreamingAsset = Path.Combine(Application.streamingAssetsPath, fileName);
byte[] result;
//Read the File from streamingAssets. Use WWW for Android
if (dbStreamingAsset.Contains("://") || dbStreamingAsset.Contains(":///"))
{
WWW www = new WWW(dbStreamingAsset);
yield return www;
result = www.bytes;
}
else
{
result = File.ReadAllBytes(dbStreamingAsset);
}
Debug.Log("Loaded db file");
//Create Directory if it does not exist
if (!Directory.Exists(Path.GetDirectoryName(dbDestination)))
{
Directory.CreateDirectory(Path.GetDirectoryName(dbDestination));
}
//Copy the data to the persistentDataPath where the database API can freely access the file
File.WriteAllBytes(dbDestination, result);
Debug.Log("Copied db file");
}
//Now you can do the database operation
//open db connection
var connection = new SqliteConnection(dbDestination);
connection.Open();
var command = connection.CreateCommand();
// Drop the table if it already exists.
command.CommandText = "DROP TABLE IF EXISTS existing_individual;";
command.ExecuteNonQuery();
var sql = "CREATE TABLE existing_individual (studentID VARCHAR(23), fullName VARCHAR(50), studentNumber VARCHAR(20))";
command.CommandText = sql;
command.ExecuteNonQuery();
//Inserting the exisiting student names returned, into the SQLite DB
int count = 0;
foreach (var individuals in jsonStudentID)
{
//looping through the existing students registered for the individual quiz - below has been written to avoid SQL injection
sql = "INSERT INTO existing_individual (studentID, fullName, studentNumber) VALUES (@jsonStudentID, @jsonIndiNames, @jsonIndiStudentNumbers)";
command.Parameters.AddWithValue("@jsonStudentID", jsonStudentID[count]);
command.Parameters.AddWithValue("@jsonIndiNames", jsonIndiNames[count]);
command.Parameters.AddWithValue("@jsonIndiStudentNumbers", jsonIndiStudentNumbers[count]);
command.CommandText = sql;
command.ExecuteNonQuery();
count++;
}
//close the connection
command.Dispose();
command = null;
connection.Close();
connection = null;
}
但是，我仍然收到以下错误：
06-08 15:26:56.498 16300-16315/? E/Unity: ArgumentException: Invalid ConnectionString format for parameter "/storage/emulated/0/Android/data/com.tbltools.tbl_project/files/data/TBLDatabase.db"
at Mono.Data.Sqlite.SqliteConnection.ParseConnectionString (System.String connectionString) [0x00000] in <filename unknown>:0
at Mono.Data.Sqlite.SqliteConnection.Open () [0x00000] in <filename unknown>:0
at UIHandler+<RunDbCode>c__Iterator3.MoveNext () [0x00000] in <filename unknown>:0
at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in <filename unknown>:0
UnityEngine.MonoBehaviour:StartCoroutineManaged2(IEnumerator)
UnityEngine.MonoBehaviour:StartCoroutine(IEnumerator)
<RequestAllStudentNames>c__Iterator2:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
(Filename: Line: -1)
06-08 15:26:56.502 16300-16315/? E/Unity: ArgumentException: Invalid ConnectionString format for parameter "URI"
at Mono.Data.Sqlite.SqliteConnection.ParseConnectionString (System.String connectionString) [0x00000] in <filename unknown>:0
at Mono.Data.Sqlite.SqliteConnection.Open () [0x00000] in <filename unknown>:0
at UIHandler.CreateIndiButton () [0x00000] in <filename unknown>:0
at UIHandler+<RequestAllStudentNames>c__Iterator2.MoveNext () [0x00000] in <filename unknown>:0
at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in <filename unknown>:0
我还将我的数据库添加到“StreamingAssets”文件夹中，如下图所示：
下面还显示了包含我的 dll 文件的插件文件夹的图像。
【问题讨论】：
-
你把数据库文件放在你项目的什么地方了？
-
@Programmer 我尝试将数据库文件存储在 assets 文件夹中，并在 assets 文件夹中创建 StreamingAssets 文件夹并将副本也存储在其中。然而，这并没有帮助。
-
嗨@Programmer！ - chat.stackoverflow.com/rooms/info/172973 ?