C#操作SQLite数据库帮助类——SQLiteHelper

时间:2022-09-20 18:31:42
using System;
using System.Collections.Generic;
using System.Data.SQLite;
using System.Data;

namespace Com.ZCWL.Rock.Helper
{
public class SQLiteHelper
{
private static string connectionString = string.Empty;

/// <summary>
/// 根据数据源、密码、版本号设置连接字符串。
/// </summary>
/// <param name="datasource">数据源。</param>
/// <param name="password">密码。</param>
/// <param name="version">版本号(缺省为3)。</param>
public static void SetConnectionString(string datasource, string password, int version = 3)
{
connectionString = string.Format("Data Source={0};Version={1};password={2}",
datasource, version, password);
}

/// <summary>
/// 创建一个数据库文件。如果存在同名数据库文件,则会覆盖。
/// </summary>
/// <param name="dbName">数据库文件名。为null或空串时不创建。</param>
/// <param name="password">(可选)数据库密码,默认为空。</param>
/// <exception cref="Exception"></exception>
public static void CreateDB(string dbName)
{
if (!string.IsNullOrEmpty(dbName))
{
try { SQLiteConnection.CreateFile(dbName); }
catch (Exception) { throw; }
}
}

/// <summary>
/// 对SQLite数据库执行增删改操作,返回受影响的行数。
/// </summary>
/// <param name="sql">要执行的增删改的SQL语句。</param>
/// <param name="parameters">执行增删改语句所需要的参数,参数必须以它们在SQL语句中的顺序为准。</param>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public int ExecuteNonQuery(string sql, params SQLiteParameter[] parameters)
{
int affectedRows = 0;
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand command = new SQLiteCommand(connection))
{
try
{
connection.Open();
command.CommandText = sql;
if (parameters.Length != 0)
{
command.Parameters.AddRange(parameters);
}
affectedRows = command.ExecuteNonQuery();
}
catch (Exception) { throw; }
}
}
return affectedRows;
}

/// <summary>
/// 批量处理数据操作语句。
/// </summary>
/// <param name="list">SQL语句集合。</param>
/// <exception cref="Exception"></exception>
public void ExecuteNonQueryBatch(List<KeyValuePair<string, SQLiteParameter[]>> list)
{
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
{
try { conn.Open(); }
catch { throw; }
using (SQLiteTransaction tran = conn.BeginTransaction())
{
using (SQLiteCommand cmd = new SQLiteCommand(conn))
{
try
{
foreach (var item in list)
{
cmd.CommandText = item.Key;
if (item.Value != null)
{
cmd.Parameters.AddRange(item.Value);
}
cmd.ExecuteNonQuery();
}
tran.Commit();
}
catch (Exception) { tran.Rollback(); throw; }
}
}
}
}

/// <summary>
/// 执行查询语句,并返回第一个结果。
/// </summary>
/// <param name="sql">查询语句。</param>
/// <returns>查询结果。</returns>
/// <exception cref="Exception"></exception>
public object ExecuteScalar(string sql, params SQLiteParameter[] parameters)
{
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand(conn))
{
try
{
conn.Open();
cmd.CommandText = sql;
if (parameters.Length != 0)
{
cmd.Parameters.AddRange(parameters);
}
return cmd.ExecuteScalar();
}
catch (Exception) { throw; }
}
}
}

/// <summary>
/// 执行一个查询语句,返回一个包含查询结果的DataTable。
/// </summary>
/// <param name="sql">要执行的查询语句。</param>
/// <param name="parameters">执行SQL查询语句所需要的参数,参数必须以它们在SQL语句中的顺序为准。</param>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public DataTable ExecuteQuery(string sql, params SQLiteParameter[] parameters)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand command = new SQLiteCommand(sql, connection))
{
if (parameters.Length != 0)
{
command.Parameters.AddRange(parameters);
}
SQLiteDataAdapter adapter = new SQLiteDataAdapter(command);
DataTable data = new DataTable();
try { adapter.Fill(data); }
catch (Exception) { throw; }
return data;
}
}
}

/// <summary>
/// 执行一个查询语句,返回一个关联的SQLiteDataReader实例。
/// </summary>
/// <param name="sql">要执行的查询语句。</param>
/// <param name="parameters">执行SQL查询语句所需要的参数,参数必须以它们在SQL语句中的顺序为准。</param>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public SQLiteDataReader ExecuteReader(string sql, params SQLiteParameter[] parameters)
{
SQLiteConnection connection = new SQLiteConnection(connectionString);
SQLiteCommand command = new SQLiteCommand(sql, connection);
try
{
if (parameters.Length != 0)
{
command.Parameters.AddRange(parameters);
}
connection.Open();
return command.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception) { throw; }
}

/// <summary>
/// 查询数据库中的所有数据类型信息。
/// </summary>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public DataTable GetSchema()
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
try
{
connection.Open();
return connection.GetSchema("TABLES");
}
catch (Exception) { throw; }
}
}
}
}

     注意:在使用该类的时候,需要引用System.Data.SQLite程序集