Unity3d 中 将远程 MySQL 数据库转换为本地 Sqlite

1、创建MySQL2Sqlite脚本mysql2sqlite.sh：（代码地址：https://gist.github.com/esperlu/943776）

#!/bin/sh

# Converts a mysqldump file into a Sqlite  compatible file. It also extracts the MySQL `KEY xxxxx` from the
# CREATE block and create them in separate commands _after_ all the INSERTs.

# Awk is choosen because it's fast and portable. You can use gawk, original awk or even the lightning fast mawk.
# The mysqldump file is traversed only once.

# Usage: $ ./mysql2sqlite mysqldump-opts db-name | sqlite3 database.sqlite
# Example: $ ./mysql2sqlite --no-data -u root -pMySecretPassWord myDbase | sqlite3 database.sqlite

# Thanks to and @artemyk and @gkuenning for their nice tweaks.

mysqldump  --compatible=ansi --skip-extended-insert --compact  "$@" | \

awk '

BEGIN {
    FS=",$"
    print "PRAGMA synchronous = OFF;"
    print "PRAGMA journal_mode = MEMORY;"
    print "BEGIN TRANSACTION;"
}

# CREATE TRIGGER statements have funny commenting.  Remember we are in trigger.
/^\/\*.*CREATE.*TRIGGER/ {
    gsub( /^.*TRIGGER/, "CREATE TRIGGER" )
    print
    inTrigger =
    next
}

# The end of CREATE TRIGGER has a stray comment terminator
/END \*\/;;/ { gsub( /\*\//, "" ); print; inTrigger = 0; next }

# The rest of triggers just get passed through
inTrigger !=  { print; next }

# Skip other comments
/^\/\*/ { next }

# Print all `INSERT` lines. The single quotes are protected by another single quote.
/INSERT/ {
    gsub( /\\\/, "\047\047" )
    gsub(/\\n/, "\n")
    gsub(/\\r/, "\r")
    gsub(/\\"/, "\"")
    gsub(/\\\\/, "\\")
    gsub(/\\\/, "\032")
    print
    next
}

# Print the `CREATE` line as is and capture the table name.
/^CREATE/ {
    print
    if ( match( $, /\"[^\"]+/ ) ) tableName = substr( $0, RSTART+1, RLENGTH-1 )
}

# Replace `FULLTEXT KEY` or any other `XXXXX KEY` except PRIMARY by `KEY`
/^  [^"]+KEY/ && !/^  PRIMARY KEY/ { gsub( /.+KEY/, "  KEY" ) }

# Get rid of field lengths in KEY lines
/ KEY/ { gsub(/\([-]+\)/, "") }

# Print all fields definition lines except the `KEY` lines.
/^  / && !/^(  KEY|\);)/ {
    gsub( /AUTO_INCREMENT|auto_increment/, "" )
    gsub( /(CHARACTER SET|character set) [^ ]+ /, "" )
    gsub( /DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP|default current_timestamp on update current_timestamp/, "" )
    gsub( /(COLLATE|collate) [^ ]+ /, "" )
    gsub(/(ENUM|enum)[^)]+\)/, "text ")
    gsub(/(SET|set)\([^)]+\)/, "text ")
    gsub(/UNSIGNED|unsigned/, "")
    if (prev) print prev ","
    prev = $
}

# `KEY` lines are extracted from the `CREATE` block and stored in array for later print
# in a separate `CREATE KEY` command. The index name is prefixed by the table name to
# avoid a sqlite error for duplicate index name.
/^(  KEY|\);)/ {
    if (prev) print prev
    prev=""
    if ($ == ");"){
        print
    } else {
        if ( match( $, /\"[^"]+/ ) ) indexName = substr( $, RSTART+, RLENGTH- )
        if ( match( $, /\([^()]+/ ) ) indexKey = substr( $, RSTART+, RLENGTH- )
        key[tableName]=key[tableName] "CREATE INDEX \"" tableName "_" indexName "\" ON \"" tableName "\" (" indexKey ");\n"
    }
}

# Print all `KEY` creation lines.
END {
    for (table in key) printf key[table]
    print "END TRANSACTION;"
}
'
exit 

2、创建convertDB.sh来调用mysql2sqlite.sh：

rm -rf sqlite_db_name
sh mysql2sqlite.sh -umysql_user_name -pmysql_user_pwd -hmysql_host mysql_db_name | sqlite3 sqlite_db_name

修改相应的参数：

　sqlite_db_name （要转换成的sqlite数据库名称）

mysql_user_name （mysql用户名称）

mysql_user_pwd （mysql用户密码）

mysql_host （mysql服务器ip地址）

mysql_db_name（要转换的mysql数据库名称）

3、在Unity3d中执行shell脚本（放在Editor文件夹下）：

using UnityEngine;
using System.Collections;
using UnityEditor;
using System.IO;
using System.Diagnostics;

public class ChangeDB  {
static string sqliteDBpath = Application.streamingAssetsPath + "/dbFile/";
    static string sqliteDBname = "sqlite_db_name.db";
    [MenuItem("Tools/Mysql to Sqlite")]
    public static void mysqlToSqlite ()
    {
        if(File.Exists(sqliteDBpath)){
            UnityEngine.Debug.Log("delete old sqlite db file...");
            File.Delete(sqliteDBpath+sqliteDBname);
        }
        if(File.Exists(sqliteDBpath+sqliteDBname+".meta")){
            File.Delete(sqliteDBpath+sqliteDBname+".meta");
        }
        //start to convert mysql to sql
        UnityEngine.Debug.Log("start convert...");
        ProcessStartInfo proc = new ProcessStartInfo();
        proc.WorkingDirectory = sqliteDBpath;
        proc.FileName = "sh";
        proc.Arguments = "convertDB.sh";
        proc.UseShellExecute = false;
        proc.Verb = "";
        Process.Start(proc);
    }
}

4、点击Tools下的 Mysql to Sqlite 就可以转换了

5、注意在iOS下可以将sqlite数据库放在 Application.streamingAssetsPath 目录下直接访问

在Android下访问Application.streamingAssetsPath下的文件必须先调用下面的方法解压一下：

string sqlitedbPath = Application.streamingAssetsPath + "/dbFile/dbname.db";

string filepath = Application.persistentDataPath + "/dbname.db";

 IEnumerator LoadSqliteDBForAndroid (string url,string newPath){

using(WWW www = new WWW(url)){

yieldreturn www;

if (www.error != null)

Debug.LogError("WWW download:" + www.error);

File.WriteAllBytes(newPath, www.bytes);

LoadAllResource();

Debug.Log("android db download finished");

        }

   }

参考资料：

1、https://gist.github.com/esperlu/943776

2、http://docs.unity3d.com/Documentation/ScriptReference/Application-streamingAssetsPath.html