Unity下使用Sqlite-编程知识

sqlite和access类似是文件形式的数据库，不需要安装任何服务，可以存储数据，使用起来还是挺方便的。

首先需要安装DLL

需要的DLL

我们找到下面两个文件放入Plugins目录
Mono.Data.Sqlite.dll
System.Data.dll
DLL文件位于Unity的安装目录下的
2022.3.14f1c1\Editor\Data\MonoBleedingEdge\lib\mono\unityjit-win32

另外还需要sqlite3.dll
在官网下载sqlite3.dll也放入Plugins

使用Sqlite

网上有网友写的SQLiteHelper，方便数据库操作，这里直接Copy了。

using UnityEngine;
using Mono.Data.Sqlite;
using System;public class SQLiteHelper
{/// <summary>/// 数据库连接定义/// </summary>private SqliteConnection dbConnection;/// <summary>/// SQL命令定义/// </summary>private SqliteCommand dbCommand;/// <summary>/// 数据读取定义/// </summary>private SqliteDataReader dataReader;/// <summary>/// 构造函数   /// </summary>/// <param name="connectionString">数据库连接字符串</param>public SQLiteHelper(string connectionString){try{//构造数据库连接dbConnection = new SqliteConnection(connectionString);//打开数据库dbConnection.Open();}catch (Exception e){Debug.Log(e.ToString());}}/// <summary>/// 执行SQL命令/// </summary>/// <returns>The query.</returns>/// <param name="queryString">SQL命令字符串</param>public SqliteDataReader ExecuteQuery(string queryString){dbCommand = dbConnection.CreateCommand();dbCommand.CommandText = queryString;dataReader = dbCommand.ExecuteReader();return dataReader;}/// <summary>/// 关闭数据库连接/// </summary>public void CloseConnection(){//销毁Commandif (dbCommand != null){dbCommand.Cancel();}dbCommand = null;//销毁Readerif (dataReader != null){dataReader.Close();}dataReader = null;//销毁Connectionif (dbConnection != null){dbConnection.Close();}dbConnection = null;}/// <summary>/// 读取整张数据表/// </summary>/// <returns>The full table.</returns>/// <param name="tableName">数据表名称</param>public SqliteDataReader ReadFullTable(string tableName){string queryString = "SELECT * FROM " + tableName;return ExecuteQuery(queryString);}/// <summary>/// 向指定数据表中插入数据/// </summary>/// <returns>The values.</returns>/// <param name="tableName">数据表名称</param>/// <param name="values">插入的数值</param>public SqliteDataReader InsertValues(string tableName, string[] values){//获取数据表中字段数目int fieldCount = ReadFullTable(tableName).FieldCount;//当插入的数据长度不等于字段数目时引发异常if (values.Length != fieldCount){throw new SqliteException("values.Length!=fieldCount");}string queryString = "INSERT INTO " + tableName + " VALUES (" + values[0];for (int i = 1; i < values.Length; i++){queryString += ", " + values[i];}queryString += " )";return ExecuteQuery(queryString);}/// <summary>/// 更新指定数据表内的数据/// </summary>/// <returns>The values.</returns>/// <param name="tableName">数据表名称</param>/// <param name="colNames">字段名</param>/// <param name="colValues">字段名相应的数据</param>/// <param name="key">关键字</param>/// <param name="value">关键字相应的值</param>public SqliteDataReader UpdateValues(string tableName, string[] colNames, string[] colValues, string key, string operation, string value){//当字段名称和字段数值不正确应时引发异常if (colNames.Length != colValues.Length){throw new SqliteException("colNames.Length!=colValues.Length");}string queryString = "UPDATE " + tableName + " SET " + colNames[0] + "=" + colValues[0];for (int i = 1; i < colValues.Length; i++){queryString += ", " + colNames[i] + "=" + colValues[i];}queryString += " WHERE " + key + operation + value;return ExecuteQuery(queryString);}/// <summary>/// 删除指定数据表内的数据/// </summary>/// <returns>The values.</returns>/// <param name="tableName">数据表名称</param>/// <param name="colNames">字段名</param>/// <param name="colValues">字段名相应的数据</param>public SqliteDataReader DeleteValuesOR(string tableName, string[] colNames, string[] operations, string[] colValues){//当字段名称和字段数值不正确应时引发异常if (colNames.Length != colValues.Length || operations.Length != colNames.Length || operations.Length != colValues.Length){throw new SqliteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");}string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[0] + operations[0] + colValues[0];for (int i = 1; i < colValues.Length; i++){queryString += "OR " + colNames[i] + operations[0] + colValues[i];}return ExecuteQuery(queryString);}/// <summary>/// 删除指定数据表内的数据/// </summary>/// <returns>The values.</returns>/// <param name="tableName">数据表名称</param>/// <param name="colNames">字段名</param>/// <param name="colValues">字段名相应的数据</param>public SqliteDataReader DeleteValuesAND(string tableName, string[] colNames, string[] operations, string[] colValues){//当字段名称和字段数值不正确应时引发异常if (colNames.Length != colValues.Length || operations.Length != colNames.Length || operations.Length != colValues.Length){throw new SqliteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");}string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[0] + operations[0] + colValues[0];for (int i = 1; i < colValues.Length; i++){queryString += " AND " + colNames[i] + operations[i] + colValues[i];}return ExecuteQuery(queryString);}/// <summary>/// 创建数据表/// </summary> +/// <returns>The table.</returns>/// <param name="tableName">数据表名</param>/// <param name="colNames">字段名</param>/// <param name="colTypes">字段名类型</param>public SqliteDataReader CreateTable(string tableName, string[] colNames, string[] colTypes){string queryString = "CREATE TABLE " + tableName + "( " + colNames[0] + " " + colTypes[0];for (int i = 1; i < colNames.Length; i++){queryString += ", " + colNames[i] + " " + colTypes[i];}queryString += "  ) ";return ExecuteQuery(queryString);}/// <summary>/// Reads the table./// </summary>/// <returns>The table.</returns>/// <param name="tableName">Table name.</param>/// <param name="items">Items.</param>/// <param name="colNames">Col names.</param>/// <param name="operations">Operations.</param>/// <param name="colValues">Col values.</param>public SqliteDataReader ReadTable(string tableName, string[] items, string[] colNames, string[] operations, string[] colValues){string queryString = "SELECT " + items[0];for (int i = 1; i < items.Length; i++){queryString += ", " + items[i];}queryString += " FROM " + tableName + " WHERE " + colNames[0] + " " + operations[0] + " " + colValues[0];for (int i = 0; i < colNames.Length; i++){queryString += " AND " + colNames[i] + " " + operations[i] + " " + colValues[0] + " ";}return ExecuteQuery(queryString);}
}

调用：

//创建名为sqlite4unity的数据库
sql = new SQLiteHelper("data source=" + Application.dataPath + "/game.db");//创建名为table1的数据表
sql.CreateTable("table1", new string[] { "ID", "Name", "Age", "Email" }, new string[] { "INTEGER", "TEXT", "INTEGER", "TEXT" });//插入两条数据
sql.InsertValues("table1", new string[] { "'1'", "'张三'", "'22'", "'Zhang3@163.com'" });
sql.InsertValues("table1", new string[] { "'2'", "'李四'", "'25'", "'Li4@163.com'" });//更新数据。将Name="张三"的记录中的Name改为"Zhang3"
sql.UpdateValues("table1", new string[] { "Name" }, new string[] { "'Zhang3'" }, "Name", "=", "'张三'");//插入3条数据
sql.InsertValues("table1", new string[] { "3", "'王五'", "25", "'Wang5@163.com'" });
sql.InsertValues("table1", new string[] { "4", "'王五'", "26", "'Wang5@163.com'" });
sql.InsertValues("table1", new string[] { "5", "'王五'", "27", "'Wang5@163.com'" });//删除Name="王五"且Age=26的记录,DeleteValuesOR方法相似
sql.DeleteValuesAND("table1", new string[] { "Name", "Age" }, new string[] { "=", "=" }, new string[] { "'王五'", "'26'" });//读取整张表
SqliteDataReader reader = sql.ReadFullTable("table1");
while (reader.Read())
{//读取IDDebug.Log(reader.GetInt32(reader.GetOrdinal("ID")));//读取NameDebug.Log(reader.GetString(reader.GetOrdinal("Name")));//读取AgeDebug.Log(reader.GetInt32(reader.GetOrdinal("Age")));//读取EmailDebug.Log(reader.GetString(reader.GetOrdinal("Email")));
}//读取数据表中Age>=25的全部记录的ID和Name
reader = sql.ReadTable("table1", new string[] { "ID", "Name" }, new string[] { "Age" }, new string[] { ">=" }, new string[] { "'25'" });
while (reader.Read())
{//读取IDDebug.Log(reader.GetInt32(reader.GetOrdinal("ID")));//读取NameDebug.Log(reader.GetString(reader.GetOrdinal("Name")));
}//自己定义SQL,删除数据表中全部Name="王五"的记录
sql.ExecuteQuery("DELETE FROM table1 WHERE NAME='王五'");//关闭数据库连接
sql.CloseConnection();