/// <summary>
/// 检查指定的数据类型是否为 Unicode
/// </summary>
/// <param name="dbType">数据类型 <see cref="System.Data.DbType"/> </param>
/// <returns></returns>
public static bool IsUnicode(object dbType)
{
if (dbType == null)
{
return(true);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.String || ((DbType)dbType) == System.Data.DbType.StringFixedLength);
}
else if (dbType is SqlDbType)
{
return(((SqlDbType)dbType) == SqlDbType.NVarChar || ((SqlDbType)dbType) == SqlDbType.NChar || ((SqlDbType)dbType) == SqlDbType.NText);
}
else
{
return(SqlServerUtils.ThrowException(dbType));
}
}
/// <summary>
/// 是否日期+时间类型
/// </summary>
/// <param name="dbType">DbType属性</param>
/// <returns></returns>
public static bool IsDateTime(object dbType)
{
if (dbType == null)
{
return(false);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.DateTime);
}
else if (dbType is SqlDbType)
{
return(((SqlDbType)dbType) == SqlDbType.DateTime);
}
else
{
return(SqlServerUtils.ThrowException(dbType));
}
}
/// <summary>
/// 设置命令参数对象的 DbType属性
/// </summary>
/// <param name="parameter">命令参数对象</param>
/// <param name="dbType">DbType属性</param>
public static void DbType(this SqlParameter parameter, object dbType)
{
if (dbType != null)
{
if (dbType is DbType)
{
parameter.DbType = (DbType)dbType;
}
else if (dbType is SqlDbType)
{
parameter.SqlDbType = (SqlDbType)dbType;
}
else
{
SqlServerUtils.ThrowException(dbType);
}
}
else if (parameter.Value != null && parameter.Value is DateTime && dbType == null)
{
// 如果 DateTime 没有指定 DbType，则需要转为 DateTime2才能保持原有的精度
parameter.DbType = System.Data.DbType.DateTime2;
}
}