c# - Oracle 和 C# - UDT 数组作为返回值

Question

我试图让 C# 读取 PL/SQL 用户定义类型的数组。

这是数组中每个对象的定义:

CREATE OR REPLACE TYPE "REPORTDATUM" AS OBJECT
(
            FIELD1                                                   VARCHAR2(20),
            FIELD2                                                   VARCHAR2(3000),
            FIELD3                                                   NUMBER(15),
            FIELD4                                                   DATE,
            FIELD5                                                   DATE,
            FIELD6                                                   VARCHAR2(4000),
            FIELD7                                                   TIMESTAMP,
            FIELD8                                                   VARCHAR2(10),
            FIELD9                                                   NUMBER(35),
            FIELD10                                                  VARCHAR2(80),
            FIELD11                                                  VARCHAR2(50)
);

CREATE OR REPLACE TYPE "REPORTARRAY" IS TABLE OF REPORTDATUM;

这是我尝试调用的函数的签名:

FUNCTION getReport(startTime IN DATE, endTime IN DATE) RETURN REPORTARRAY;

现在，根据我在这里找到的指南:http://appsjack.blogspot.com/2010/09/pass-custom-udt-types-to-oracle-stored.html

我创建了 ReportDatum.cs 类，如下所示:

public class ReportDatum : INullable,  IOracleCustomType {

    private bool objectIsNull;

    [OracleObjectMappingAttribute(Constants.ReportDatum.Aliases.Field1)]
    public string Field1 { get; set; }

    [OracleObjectMappingAttribute(Constants.ReportDatum.Aliases.Field2)]
    public string Field2 { get; set; }

                            [...]

    [OracleObjectMappingAttribute(Constants.ReportDatum.Aliases.Field11)]
    public string Field11 { get; set; }


    public static ReportDatum Null {
        get {
            ReportDatum reportDatum = new ReportDatum();
            reportDatum.objectIsNull = true;
            return reportDatum;
        }
    }

    public bool IsNull {
        get { return objectIsNull; }
    }

    public void FromCustomObject(OracleConnection databaseConnection, IntPtr userDefinedTypePointer) {
        if (string.IsNullOrEmpty(this.Field1) == false ) {
            OracleUdt.SetValue(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field1, this.Field1);
        }
        if (string.IsNullOrEmpty(this.Field2) == false) {
            OracleUdt.SetValue(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field2, this.Field2);
        }
        [...]
        if (string.IsNullOrEmpty(this.Field11) == false) {
            OracleUdt.SetValue(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field11, this.Field11);
        }
    }

    public void ToCustomObject(OracleConnection databaseConnection, IntPtr userDefinedTypePointer) {
        this.Field1 = parseString(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field1);
        this.Field2 = parseString(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field2);
                                            [...]
        this.Field11 = parseString(databaseConnection, userDefinedTypePointer, Constants.ReportDatum.Aliases.Field11);
    }

    private string parseString(OracleConnection databaseConnection, IntPtr userDefinedTypePointer, string columnName) {
        string valueToReturn = String.Empty;
        try {
            valueToReturn = ( String ) OracleUdt.GetValue(databaseConnection, userDefinedTypePointer, columnName);
        }
        catch (Exception e) {
            error("Exception while attempting to parse string value of column [" + columnName + "]. Message [" + (e == null || e.Message == null ? "NULL" : e.Message) + "]", e);
        }
        return valueToReturn;
    }

 }

我还继续创建 ReportDatumFactory.cs，如下所示:

public class ReportDatumFactory : IOracleCustomTypeFactory {

    public IOracleCustomType CreateObject() {
        return new ReportDatum();
    }

}

根据我上面链接的指南，这应该足以处理组成数组的每个项目。

为了处理数组本身，我创建了以下类。

ReportArray.cs

public class ReportArray : INullable, IOracleCustomType {

    [OracleArrayMapping()]
    public ReportDatum[] reportArray;

    private bool objectIsNull;

    public bool IsNull {
        get { return objectIsNull; }
    }

    public void FromCustomObject(OracleConnection databaseConnection, IntPtr userDefinedTypePointer) {
        try {
            OracleUdt.SetValue(databaseConnection, userDefinedTypePointer, 0, reportArray);
        }
        catch (Exception e) {
            error("Exception while populating OracleUdt from ReportArray.", e);
        }
    }

    public void ToCustomObject(OracleConnection databaseConnection, IntPtr userDefinedTypePointer) {
        try {
            reportArray = ( ReportDatum[] ) OracleUdt.GetValue(databaseConnection, userDefinedTypePointer, 0);
        }
        catch (Exception e) {
            error("Exception while reading values from OracleUdt related to ReportArray.", e);
        }
    }

}         

以及关联的工厂类

ReportArrayFactory.cs

public class ReportArrayFactory : IOracleCustomTypeFactory, IOracleArrayTypeFactory {

    public IOracleCustomType CreateObject() {
        return new ReportArray();
    }


    public Array CreateArray(int numberOfElements) {
        return new ReportArray[numberOfElements];
    }

    public Array CreateStatusArray(int numberOfElements) {
        return null;
    }

}

现在，关于调用存储过程的方法，这就是我所拥有的:

报告.cs

    private void executeStoredProcedure2(OracleConnection databaseConnection, string schema, string storedProcedureName, DateTime startTime, DateTime endTime, int numberOfElements) {
        OracleCommand databaseCommand = new OracleCommand();
        ReportArray reportArray = new ReportArray();

        debug("Attempting to populate the report array");
        if (databaseConnection != null && databaseConnection.State == ConnectionState.Open) {
            try {
                databaseCommand.Connection = databaseConnection;
                databaseCommand.CommandType = CommandType.StoredProcedure;
                databaseCommand.CommandText = schema + "." + storedProcedureName;
                databaseCommand.Parameters.Add(createUserDefinedParameter(numberOfElements, reportArray));
                databaseCommand.Parameters.Add(Constants.ReportDatum.ParameterNames.startTime, OracleDbType.Date, startTime, ParameterDirection.Input);
                databaseCommand.Parameters.Add(Constants.ReportDatum.ParameterNames.endTime, OracleDbType.Date, endTime, ParameterDirection.Input);
                databaseCommand.ExecuteNonQuery();
                //How do I populate the reportArray object?
            }
            catch (Exception exception) {
                error("Exception while executing stored procedure [" + storedProcedure2 + "].", exception);
            }
            finally {
                databaseCommand.Dispose();
            }
        }
    }



    private OracleParameter createUserDefinedParameter(int size, ReportArray reportArray) {
        OracleParameter valueToReturn = null;
        try {
            valueToReturn = new OracleParameter();
            valueToReturn.ParameterName = "reportData"; //this is the name of the REPORTARRAY object in the Oracle function that is being returned.
            valueToReturn.OracleDbType = OracleDbType.Array;
            valueToReturn.Direction = ParameterDirection.ReturnValue;
            valueToReturn.CollectionType = OracleCollectionType.PLSQLAssociativeArray;
            valueToReturn.UdtTypeName = Constants.ReportDatum.arrayDataTypeDefinition;
            valueToReturn.ArrayBindSize = new int[size];
            valueToReturn.ArrayBindStatus = new OracleParameterStatus[size];
            valueToReturn.Size = size;
            valueToReturn.Value = reportArray.reportArray;
        }
        catch (Exception e) {
            error("Exception while attempting to create user defined parameter.", e);
        }
        return valueToReturn;
    }

我面临的问题是我无法在 C# 中获取数组。有人遇到过这个问题吗？我错过了什么？

我有理由相信 SQL 代码正在运行。目前只有 C# 造成了问题。

Answer 1

看起来有一些问题。

首先，工厂需要 OracleCustomTypeMapping 属性。如果没有它们，Oracle 根本不会认为应该使用这些映射工厂类:

    [OracleCustomTypeMapping("SCHEMA.REPORTDATUM")]
    public class ReportDatum ...

和

    [OracleCustomTypeMapping("SCHEMA.REPORTARRAY")]
    public class ReportArray ...

其次，数组映射工厂有一个错误:创建数组时，您想要创建一个 ReportDatum 对象数组。目前，您正在创建一个 ReportArray 对象数组，即一个数组数组，这是您不需要的。换句话说，替换

    public Array CreateArray(int numberOfElements) {
        return new ReportArray[numberOfElements];
    }

与

    public Array CreateArray(int numberOfElements) {
        return new ReportDatum[numberOfElements];
    }

第三，删除该行

        CollectionType = OracleCollectionType.PLSQLAssociativeArray,

来自您的createUserDefinedParameter方法。返回的值不是 PL/SQL 关联数组(它是一种不同类型的集合)，因此不应使用此属性。如果您使用此属性，您可能会发现从存储函数返回的返回值是一个空的 object 数组。

最后，要从存储的函数调用中获取数组，请在对 databaseCommand.ExecuteNonQuery() 的调用后添加以下行:

    reportArray = (ReportArray)databaseCommand.Parameters["reportData"].Value;