主要功能：增删改查、自定义SQL执行、批量执行（事务）、防SQL注入、异常处理
1.NuGet中安装System.Data.SQLite
2.SQLiteHelper的封装：
using System;
using System.Collections.Generic;
using System.Data.SQLite;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace inventory_management_system.jdbc
{
public class SQLiteHelper
{
private SQLiteConnection _connection;
public SQLiteHelper(string databasePath)
{
_connection = new SQLiteConnection($"Data Source={databasePath};Version=3;BinaryGUID=False;");
}
public void OpenConnection()
{
if (_connection.State != ConnectionState.Open)
{
_connection.Open();
}
}
public void CloseConnection()
{
if (_connection.State != ConnectionState.Closed)
{
_connection.Close();
}
}
/// <summary>
/// 执行插入操作
/// </summary>
/// <param name="tableName">表名</param>
/// <param name="key_values">键值对字典</param>
/// <returns>int</returns>
public int Insert(string tableName, Dictionary<string, object> key_values)
{
using (var cmd = _connection.CreateCommand())
{
List<string> columns = new List<string>();
List<SQLiteParameter> parameters = new List<SQLiteParameter>();
int index = 0;
foreach (var kvp in key_values)
{
columns.Add(kvp.Key);
parameters.Add(new SQLiteParameter($"@{kvp.Key}", kvp.Value));
cmd.Parameters.Add(parameters[index]);
index++;
}
string query = $"INSERT INTO {tableName} ({string.Join(",", columns)}) VALUES ({string.Join(",", parameters.Select(p => "@" + p.ParameterName))})";
cmd.CommandText = query;
return cmd.ExecuteNonQuery();
}
}
/// <summary>
/// 执行更新操作
/// </summary>
/// <param name="tableName">表名</param>
/// <param name="setValues">新数据</param>
/// <param name="whereClause">条件</param>
/// <param name="parameters">条件数据</param>
/// <returns>int</returns>
public int Update(string tableName, Dictionary<string, object> setValues, string whereClause, List<SQLiteParameter> parameters)
{
using (var cmd = _connection.CreateCommand())
{
List<string> setColumns = new List<string>();
int index = 0;
foreach (var kvp in setValues)
{
setColumns.Add($"{kvp.Key} = @{kvp.Key}");
cmd.Parameters.Add(new SQLiteParameter($"@{kvp.Key}", kvp.Value));
index++;
}
string query = $"UPDATE {tableName} SET {string.Join(",", setColumns)} WHERE {whereClause}";
cmd.CommandText = query;
cmd.Parameters.AddRange(parameters.ToArray());
return cmd.ExecuteNonQuery();
}
}
/// <summary>
/// 执行删除操作
/// </summary>
/// <param name="tableName">表名</param>
/// <param name="whereClause">条件</param>
/// <param name="parameters">参数数据</param>
/// <returns>int</returns>
public int Delete(string tableName, string whereClause, List<SQLiteParameter> parameters)
{
using (var cmd = _connection.CreateCommand())
{
cmd.CommandText = $"DELETE FROM {tableName} WHERE {whereClause}";
cmd.Parameters.AddRange(parameters.ToArray());
return cmd.ExecuteNonQuery();
}
}
/// <summary>
/// 执行查询操作
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="parameters">参数数据</param>
/// <returns>DataTable</returns>
public DataTable Select(string sql, List<SQLiteParameter> parameters)
{
DataTable dt = new DataTable();
using (var cmd = _connection.CreateCommand())
{
cmd.CommandText = sql;
cmd.Parameters.AddRange(parameters.ToArray());
using (var reader = cmd.ExecuteReader())
{
dt.Load(reader);
}
}
return dt;
}
/// <summary>
/// 执行自定义SQL语句，返回影响行数
/// </summary>
/// <param name="sql"></param>
/// <returns>int类型</returns>
public int ExecuteSQL(string sql)
{
using (var cmd = _connection.CreateCommand())
{
cmd.CommandText = sql;
return cmd.ExecuteNonQuery();
}
}
/// <summary>
/// 执行自定义SQL语句，返回影响行数
/// </summary>
/// <param name="sql"></param>
/// <param name="parameters"></param>
/// <returns>int类型</returns>
public int ExecuteSQL(string sql, List<SQLiteParameter> parameters)
{
using (var cmd = _connection.CreateCommand())
{
cmd.CommandText = sql;
cmd.Parameters.AddRange(parameters.ToArray());
return cmd.ExecuteNonQuery();
}
}
/// <summary>
/// 执行自定义sql查询语句,如果你计划对返回的 DataTable 进行大量的后续操作（例如，添加或删除行，修改列值等），那么使用 SQLiteDataAdapter 可能会更有优势，因为它提供了更高级的数据绑定和更新功能
/// </summary>
/// <param name="sql"></param>
/// <param name="parameters"></param>
/// <returns>DataTable</returns>
public DataTable ExecuteSelect(string sql, List<SQLiteParameter> parameters)
{
using (SQLiteCommand command = _connection.CreateCommand())
{
command.CommandText = sql;
command.Parameters.AddRange(parameters.ToArray());
using (SQLiteDataAdapter adapter = new SQLiteDataAdapter(command))
{
DataTable dataTable = new DataTable();
adapter.Fill(dataTable); // 填充数据表
return dataTable; // 返回查询结果的数据表
}
}
}
/// <summary>
/// 批量操作
/// </summary>
/// <param name="sql"></param>
/// <param name="parameters"></param>
/// <returns></returns>
public int BatchExecuteSQL(string sql, List<List<SQLiteParameter>> parameters)
{
int affectedRows = 0;
using (var transaction = _connection.BeginTransaction())
{
try
{
using (var cmd = _connection.CreateCommand())
{
cmd.Transaction = transaction;
foreach (var paramList in parameters)
{
cmd.CommandText = sql;
cmd.Parameters.Clear();
cmd.Parameters.AddRange(paramList.ToArray());
affectedRows += cmd.ExecuteNonQuery();
}
transaction.Commit(); // 提交事务
}
}
catch (Exception ex)
{
transaction.Rollback(); // 发生异常时回滚事务
throw; // 重新抛出异常，以便上层调用者处理
}
}
return affectedRows;
}
}
}
3.SQLiteHelper使用示例：
public void test()
{
string databasePath = "path_to_your_database.db"; // 替换为你的数据库文件路径
SQLiteHelper helper = new SQLiteHelper(databasePath);
try
{
// 打开数据库连接
helper.OpenConnection();
// 插入数据示例
Dictionary<string, object> valuesToInsert = new Dictionary<string, object>
{
{ "Name", "John Doe" },
{ "Age", 30 },
{ "Email", "johndoe@example.com" }
};
int insert_count = helper.Insert("Users", valuesToInsert);
// 更新数据示例
Dictionary<string, object> valuesToUpdate = new Dictionary<string, object>
{
{ "Age", 31 }
};
int update_count = helper.Update("Users", valuesToUpdate, "Name = @Name", new List<SQLiteParameter>(){ new SQLiteParameter("@Name", "John Doe") });
// 删除数据示例
int delete_count = helper.Delete("Users", "Name = @Name", new List<SQLiteParameter>() { new SQLiteParameter("@Name", "John Doe") });
// 查询数据示例
DataTable dataTable = helper.Select("SELECT * FROM Users WHERE Name = @Name", new List<SQLiteParameter>() { new SQLiteParameter("@Name", "John Doe") });
foreach (DataRow row in dataTable.Rows)
{
Console.WriteLine($"Name: {row["Name"]}, Age: {row["Age"]}, Email: {row["Email"]}");
}
//批量操作示例
string sql = "INSERT INTO Users (Name,Age,Email) VALUES (@Name,@Age,@Email);";
List<List<SQLiteParameter>> parameterList = new List<List<SQLiteParameter>>();
for (int i = 0; i < 10; i++)
{
List<SQLiteParameter> parameters = new List<SQLiteParameter>();
parameters.Add(new SQLiteParameter("@Name", $"名字{i}"));
parameters.Add(new SQLiteParameter("@Age", i));
parameters.Add(new SQLiteParameter("@Email", $"邮箱{i}"));
parameterList.Add(parameters);
}
int batch_count = helper.BatchExecuteSQL(sql, parameterList);
}
catch (Exception ex)
{
Console.WriteLine("An error occurred: " + ex.Message);
}
finally
{
// 关闭数据库连接
helper.CloseConnection();
}
}
