Enterprise Library- Data Block运用oracle存储历程，字符串参数传入值为时出现后果的处置惩罚
前导发轫：culturenet的 Blog 作者：culturenet的 Blog">
在挪用存储历程时，发作如下错误：
Parameter ''''p_R_URL'''': No size set for variable length data type: String.
剖析');: 实行当前 Web 苦求时期，出现未处置惩罚的十分。请反省货仓跟踪信息，以认识有关该错误以及代码中招致错误的来由的具体信息。
十分具体信息: System.Exception: Parameter ''''p_R_URL'''': No size set for variable length data type: String.
源错误:
行 67： catch(Exception ex)
行 68： {
行 69： throw new Exception(ex.Message);
行 70： //return false;
行 71： }源文件: c:inetpubwwwrootresourcedatalaydbresource.cs 行: 69
货仓跟踪:
[Exception: Parameter ''''p_R_URL'''': No size set for variable length data type: String.]
ReSource.DataLay.DbResource.Insert(String R_TITLE, String R_USE, String R_XKML, String R_GRLB, String R_WJLB, DateTime R_ADDTIME, String R_URL, String R_PRIVATE, String R_COMMONT) in c:inetpubwwwrootresourcedatalaydbresource.cs:69
ReSource.BusLay.BusResource.Insert() in c:inetpubwwwrootresourcebuslaybusresource.cs:119
ReSource.WebLay.MYRESOURCEAdd.Insert(Object sender, EventArgs e) in c:inetpubwwwrootresourceweblaytjzymyresourceadd.aspx.cs:80
System.EventHandler.Invoke(Object sender, EventArgs e) 0
System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e) 108
System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) 57
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) 18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) 138
System.Web.UI.Page.ProcessRequestMain() 1292
版本信息: Microsoft .NET Framework 版本:1.1.4322.2300; ASP.NET 版本:1.1.4322.2300
十分担忧，于是就翻开Enterprise Library的源代码终了调试。发现后果正本出今朝 OracleCommandWrapper.cs文件中的 如下函数：（从345 行入手动手）
private OracleParameter CreateParameter(string name, DbType dbType, int size, ParameterDirection direction, bool nullable, byte precision, byte scale, string sourceColumn, DataRowVersion sourceVersion, object value)
{
OracleParameter param = this.command.CreateParameter(); param.ParameterName = name; param.DbType = dbType; param.Size = size; param.Value = (value == null) ? DBNull.Value : value; // modify parameter type and value for special cases switch (dbType)
{ // for Guid, change to value to byte array case DbType.Guid: guidParameters.Add(param.ParameterName, "System.Guid"); param.OracleType = OracleType.Raw; param.Size = 16; // convert Guid value to byte array only if not null if ((value is DBNull) || (value == null)) { param.Value = Convert.DBNull;
} else { param.Value = ((Guid)value).ToByteArray(); } break; // case DbType.AnsiString: // case DbType.AnsiStringFixedLength: // case DbType.String: // case DbType.StringFixedLength: // // for empty string, set it to DBNull // if ((value == null) || (!(value is DBNull)) && ((string)value).Length == 0) // { // param.Value = Convert.DBNull; // } // break; default: break; } param.Direction = direction; param.IsNullable = nullable; param.Precision = precision; param.Scale = scale; param.SourceColumn = sourceColumn; param.SourceVersion = sourceVersion; return param;
}
可以看到，代码中处置惩罚了传入值为 NULL的环境。但是不知道为什么把处置惩罚字符串参数即是 "" 的时分得语句给解释失了。于是乎，就更动源代码，如下：
private OracleParameter CreateParameter(string name, DbType dbType, int size, ParameterDirection direction, bool nullable, byte precision, byte scale, string sourceColumn, DataRowVersion sourceVersion, object value) { OracleParameter param = this.command.CreateParameter(); param.ParameterName = name; param.DbType = dbType; param.Size = size; param.Value = (value == null) ? DBNull.Value : value; // modify parameter type and value for special cases switch (dbType) { // for Guid, change to value to byte array case DbType.Guid: guidParameters.Add(param.ParameterName, "System.Guid"); param.OracleType = OracleType.Raw; param.Size = 16; // convert Guid value to byte array only if not null if ((value is DBNull) || (value == null)) { param.Value = Convert.DBNull; } else { param.Value = ((Guid)value).ToByteArray(); } break; case DbType.AnsiString: case DbType.AnsiStringFixedLength: case DbType.String: case DbType.StringFixedLength: // for empty string, set it to DBNull if ((value == null) || (!(value is DBNull)) && ((string)value).Length == 0) { param.Value = Convert.DBNull; } break; default: break; } param.Direction = direction; param.IsNullable = nullable; param.Precision = precision; param.Scale = scale; param.SourceColumn = sourceColumn; param.SourceVersion = sourceVersion; return param; }
后果的到认识决。但是不知道微软的代码为什么把这个给解释失了。
其后，上网上看到Oracle 的一个论坛上的帖子上有如下的描摹：
Oracle will treat '''''''' (empty string) as
NULL, and store as NULL anyway - better be prepared for it, and
treat it as such.
版本信息: Microsoft .NET Framework 版本:1.1.4322.2300; ASP.NET 版本:1.1.4322.2300
十分担忧，于是就翻开Enterprise Library的源代码终了调试。发现后果正本出今朝 OracleCommandWrapper.cs文件中的 如下函数：（从345 行入手动手）
private OracleParameter CreateParameter(string name, DbType dbType, int size, ParameterDirection direction, bool nullable, byte precision, byte scale, string sourceColumn, DataRowVersion sourceVersion, object value) { OracleParameter param = this.command.CreateParameter(); param.ParameterName = name; param.DbType = dbType; param.Size = size; param.Value = (value == null) ? DBNull.Value : value; // modify parameter type and value for special cases switch (dbType) { // for Guid, change to value to byte array case DbType.Guid: guidParameters.Add(param.ParameterName, "System.Guid"); param.OracleType = OracleType.Raw; param.Size = 16; // convert Guid value to byte array only if not null if ((value is DBNull) || (value == null)) { param.Value = Convert.DBNull; } else { param.Value = ((Guid)value).ToByteArray(); } break; // case DbType.AnsiString: // case DbType.AnsiStringFixedLength: // case DbType.String: // case DbType.StringFixedLength: // // for empty string, set it to DBNull // if ((value == null) || (!(value is DBNull)) && ((string)value).Length == 0) // { // param.Value = Convert.DBNull; // } // break; default: break; } param.Direction = direction; param.IsNullable = nullable; param.Precision = precision; param.Scale = scale; param.SourceColumn = sourceColumn; param.SourceVersion = sourceVersion; return param; }
可以看到，代码中处置惩罚了传入值为 NULL的环境。但是不知道为什么把处置惩罚字符串参数即是 "" 的时分得语句给解释失了。于是乎，就更动源代码，如下：
private OracleParameter CreateParameter(string name, DbType dbType, int size, ParameterDirection direction, bool nullable, byte precision, byte scale, string sourceColumn, DataRowVersion sourceVersion, object value) { OracleParameter param = this.command.CreateParameter(); param.ParameterName = name; param.DbType = dbType; param.Size = size; param.Value = (value == null) ? DBNull.Value : value; // modify parameter type and value for special cases switch (dbType) { // for Guid, change to value to byte array case DbType.Guid: guidParameters.Add(param.ParameterName, "System.Guid"); param.OracleType = OracleType.Raw; param.Size = 16; // convert Guid value to byte array only if not null if ((value is DBNull) || (value == null)) { param.Value = Convert.DBNull; } else { param.Value = ((Guid)value).ToByteArray(); } break; case DbType.AnsiString: case DbType.AnsiStringFixedLength: case DbType.String: case DbType.StringFixedLength: // for empty string, set it to DBNull if ((value == null) || (!(value is DBNull)) && ((string)value).Length == 0) { param.Value = Convert.DBNull; } break; default: break; } param.Direction = direction; param.IsNullable = nullable; param.Precision = precision; param.Scale = scale; param.SourceColumn = sourceColumn; param.SourceVersion = sourceVersion; return param; }
后果的到认识决。但是不知道微软的代码为什么把这个给解释失了。
其后，上网上看到Oracle 的一个论坛上的帖子上有如下的描摹：
Oracle will treat '''''''' (empty string) as
NULL, and store as NULL anyway - better be prepared for it, and
treat it as such.
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