【Unity】C#使用sqlite作为数据库解决方案思路

1，编辑器建立好数据库结构，生成sqlite数据库文件，可以用navicat图形界面编辑器来操作。

2，建立好的数据库，后缀名变为.txt格式（方便unity3d加载），放文件放到Assest/Resources目录下（新建目录）。
放在Resources目录下的文件，在Pc/ios/android端均可以不作区分的用Resource来加载，假设数据库文件名位：data.txt,语句如下：
TextAsset txt = Resources.Load ("data", typeof(TextAsset))as TextAsset;

3, 将读取到的TextAsset文件写入对应平台的沙盒路径下, 代码为：

   databaseFilePath = Application.persistentDataPath+"//"+data.db;（沙盒，各平台路径不同，均为可读写）

      File.WriteAllBytes(databaseFilePath,txt.bytes);

4，加载沙盒路径下的数据库文件进行读写操作。DbAccess封装了数据库操作。其中需要两个dll文件，一个so文件（android平台需要libsq

<span><span class="keyword">using</span><span> UnityEngine;</span></span>
using System.Collections;
using Mono.Data.Sqlite;
using System;
using System.IO;

public class DbAccess{

private SqliteConnection dbConnection;

private SqliteCommand dbCommand;

private SqliteDataReader reader;

public DbAccess (string connectionString)
{
OpenDB (connectionString);
}
public DbAccess ()
{

}

public void OpenDB (string connectionString)
{
try
{
dbConnection = new SqliteConnection (connectionString);

dbConnection.Open ();

Debug.Log ("Connected to db");
}
catch(Exception e)
{
string temp1 = e.ToString();
Debug.Log(temp1);
}
}

public void CloseSqlConnection ()
{

if (dbCommand != null) {

dbCommand.Dispose ();

}

dbCommand = null;

if (reader != null) {

reader.Dispose ();

}

reader = null;

if (dbConnection != null) {

dbConnection.Close ();

}

dbConnection = null;

Debug.Log ("Disconnected from db.");

}

public SqliteDataReader ExecuteQuery (string sqlQuery)

{

dbCommand = dbConnection.CreateCommand ();

dbCommand.CommandText = sqlQuery;

reader = dbCommand.ExecuteReader ();

return reader;

}

public SqliteDataReader ReadFullTable (string tableName)

{

string query = "SELECT * FROM " + tableName;

return ExecuteQuery (query);

}

public SqliteDataReader InsertInto (string tableName, string[] values)

{

string query = "INSERT INTO " + tableName + " VALUES (" + values[0];

for (int i = 1; i < values.Length; ++i) {

query += ", " + values[i];

}

query += ")";

return ExecuteQuery (query);

}

public SqliteDataReader UpdateInto (string tableName, string []cols,string []colsvalues,string selectkey,string selectvalue)
{

string query = "UPDATE "+tableName+" SET "+cols[0]+" = "+colsvalues[0];

for (int i = 1; i < colsvalues.Length; ++i) {

query += ", " +cols[i]+" ="+ colsvalues[i];
}

query += " WHERE "+selectkey+" = "+selectvalue+" ";

return ExecuteQuery (query);
}

public SqliteDataReader Delete(string tableName,string []cols,string []colsvalues)
{
string query = "DELETE FROM "+tableName + " WHERE " +cols[0] +" = " + colsvalues[0];

for (int i = 1; i < colsvalues.Length; ++i) {

query += " or " +cols[i]+" = "+ colsvalues[i];
}
Debug.Log(query);
return ExecuteQuery (query);
}

public SqliteDataReader InsertIntoSpecific (string tableName, string[] cols, string[] values)

{

if (cols.Length != values.Length) {

throw new SqliteException ("columns.Length != values.Length");

}

string query = "INSERT INTO " + tableName + "(" + cols[0];

for (int i = 1; i < cols.Length; ++i) {

query += ", " + cols[i];

}

query += ") VALUES (" + values[0];

for (int i = 1; i < values.Length; ++i) {

query += ", " + values[i];

}

query += ")";

return ExecuteQuery (query);

}

public SqliteDataReader DeleteContents (string tableName)

{

string query = "DELETE FROM " + tableName;

return ExecuteQuery (query);

}

public SqliteDataReader CreateTable (string name, string[] col, string[] colType)

{

if (col.Length != colType.Length) {

throw new SqliteException ("columns.Length != colType.Length");

}

string query = "CREATE TABLE " + name + " (" + col[0] + " " + colType[0];

for (int i = 1; i < col.Length; ++i)
{

query += ", " + col[i] + " " + colType[i];

}

query += ")";

return ExecuteQuery (query);

}

public SqliteDataReader SelectWhere (string tableName, string[] items, string[] col, string[] operation, string[] values)

{

if (col.Length != operation.Length ||operation.Length != values.Length) {

throw new SqliteException ("col.Length != operation.Length != values.Length");

}

string query = "SELECT " + items[0];

for (int i = 1;i < items.Length; ++i) {

query += ", " + items[i];

}
if (col.Length == 0) {
query += " FROM " + tableName;
} else
{
query += " FROM " + tableName + " WHERE " + col[0] + operation[0] + "'" + values[0] + "' ";

for (int i = 1; i < col.Length; ++i) {

query += " AND " + col[i] + operation[i] + "'" + values[0] + "' ";

}
}

return ExecuteQuery (query);

}
}

public class DataCenter{

private string databaseFilename = "data.db";

private string databaseFilePath;

private DbAccess dbaccess;

public DataCenter()
{
databaseFilePath = Application.persistentDataPath+"//"+databaseFilename;

if (!File.Exists (databaseFilePath))
{
TextAsset txt = Resources.Load ("data", typeof(TextAsset))as TextAsset;

File.WriteAllBytes(databaseFilePath,txt.bytes);

//copy data file to sandbox
}

dbaccess = new DbAccess (@"Data Source=" + databaseFilePath);
}
}