/// <summary>
/// 根据数据库类型获取所对应的数据库操作实例
/// </summary>
/// <param name="providerType"></param>
/// <returns></returns>
internal static DbProviderFactory GetDbProviderFactory(EDbProviderType providerType)
{
if (!ProviderFactoryDict.ContainsKey(providerType))
{
ProviderFactoryDict.Add(providerType, DbProviderFactories.GetFactory(ProviderNameDict[providerType]));
}
return(ProviderFactoryDict[providerType]);
}
/// <summary>
/// 提供连接和使用SQL操作不同类型的数据库(数据源)的方法
/// </summary>
/// <param name="connectionString">数据库连接字符串</param>
/// <param name="providerType">数据库类型</param>
/// <param name="commandTimeOut">执行一条命令的超时时间（以秒为单位）</param>
protected DbHelper(string connectionString, EDbProviderType providerType, int commandTimeOut = 30)
{
ConnectionString = connectionString;
CommandTimeOut = commandTimeOut;
_providerFactory = ProviderFactory.GetDbProviderFactory(providerType);
if (_providerFactory == null)
{
throw new ArgumentException($"无法加载数据源类型为“{providerType.ToString()}”的数据库操作对象(ProviderFactory)");
}
}
/// <summary>
/// 从数据库中获取字典表，注意字典表只有两个字段即“编码”、“名称”
/// </summary>
/// <param name="connectString"></param>
/// <param name="tableName"></param>
/// <param name="eDbProviderType"></param>
/// <param name="codeField">编码字段名</param>
/// <param name="nameField">名称字段名</param>
/// <returns></returns>
protected static DictionaryTable GetDictionaryTableFromDb(string connectString, string tableName,
EDbProviderType eDbProviderType, string codeField = "编码", string nameField = "名称")
{
var sql = $"select {codeField},{nameField} from " + tableName;
var dbHelper = DbHelper.GetDbHelper(connectString, eDbProviderType);
var dataTable = dbHelper.GetDataTable(sql);
var dictTable = new DictionaryTable(tableName);
foreach (DataRow row in dataTable.Rows)
{
dictTable.CodeNameDict.Add(row[0].ToString(), row[1].ToString());
}
dbHelper.Close();
return(dictTable);
}
/// <summary> /// 构建操作数据库(数据源)的帮助类 /// </summary> /// <param name="connectionString">数据库连接字符串</param> /// <param name="providerType">数据库类型</param> /// <param name="commandTimeOut">执行一条命令的超时时间（以秒为单位）</param> public static DbHelper GetDbHelper(string connectionString, EDbProviderType providerType, int commandTimeOut = 30) => new DbHelper(connectionString, providerType, commandTimeOut);
/// <summary>
/// 根据数据库类型获取所对应的数据提供程序名
/// </summary>
/// <param name="providerType">数据库类型</param>
/// <returns></returns>
internal static string GetProviderName(EDbProviderType providerType)
{
return(ProviderNameDict[providerType]);
}
/// <summary>
/// 从数据库中获取字典表
/// </summary>
/// <param name="connectString"></param>
/// <param name="tableName">字典表名称</param>
/// <param name="eDbProviderTyp"></param>
/// <returns></returns>
public static DictionaryTable GetDictionaryTable(string connectString, string tableName, EDbProviderType eDbProviderTyp)
{
var dictTables = new Dictionary <string, DictionaryTable>();
if (dictTables.ContainsKey(tableName))
{
return(dictTables[tableName]);
}
var tableFields = GetDictionaryTableFromDb(connectString, tableName, eDbProviderTyp);
dictTables.Add(tableName, tableFields);
return(tableFields);
}
