Oracle SQL-如何使用JSP调用ODCI流水线函数

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以下是https://docs.oracle.com/cd/B28359_01/appdev.111/b28425/pipelined_example.htm#CHDHDHEE的确切实现

假设我们具有以下表定义：
CREATE TABLE StockTable (
  ticker VARCHAR(4),
  openprice NUMBER,
  closeprice NUMBER
);
然后，我们得到以下类型（作为对象的基本类型和作为表的类型）：
CREATE TYPE TickerType AS OBJECT
(
  ticker VARCHAR2(4),
  PriceType VARCHAR2(1),
price NUMBER
);
/
CREATE TYPE TickerTypeSet AS TABLE OF TickerType;
此外，我们还定义了ODCI类型及其在数据库中的SQL和Java存储过程中的实现：
SQL：
CREATE OR REPLACE TYPE StockPivotImpl AS OBJECT
(
  key INTEGER,
  STATIC FUNCTION ODCITableStart(sctx OUT StockPivotImpl, cur SYS_REFCURSOR)
RETURN NUMBER
AS LANGUAGE JAVA
NAME 'StockPivotImpl.ODCITableStart(oracle.sql.STRUCT[], java.sql.ResultSet) return java.math.BigDecimal',
  MEMBER FUNCTION ODCITableFetch(self IN OUT StockPivotImpl, nrows IN NUMBER,
                              outSet OUT TickerTypeSet) RETURN NUMBER
AS LANGUAGE JAVA
NAME 'StockPivotImpl.ODCITableFetch(java.math.BigDecimal, oracle.sql.ARRAY[]) return java.math.BigDecimal',
  MEMBER FUNCTION ODCITableClose(self IN StockPivotImpl) RETURN NUMBER
AS LANGUAGE JAVA
NAME 'StockPivotImpl.ODCITableClose() return java.math.BigDecimal'
);
/
Java存储过程：
import java.io.*;
import java.util.*;
import oracle.sql.*;
import java.sql.*;
import java.math.BigDecimal;
import oracle.CartridgeServices.*;
// stored context type
public class StoredCtx
{
  ResultSet rset;
  public StoredCtx(ResultSet rs) { rset=rs; }
}
// implementation type
public class StockPivotImpl implements SQLData
{
  private BigDecimal key;
  final static BigDecimal SUCCESS = new BigDecimal(0);
  final static BigDecimal ERROR = new BigDecimal(1);
  // Implement SQLData interface.
  String sql_type;
  public String getSQLTypeName() throws SQLException
  {
return sql_type;
  }
  public void readSQL(SQLInput stream, String typeName) throws SQLException
  {
sql_type = typeName;
key = stream.readBigDecimal();
  }
  public void writeSQL(SQLOutput stream) throws SQLException
  {
stream.writeBigDecimal(key);
  }
  // type methods implementing ODCITable interface
  static public BigDecimal ODCITableStart(STRUCT[] sctx,ResultSet rset)
throws SQLException
  {
Connection conn = DriverManager.getConnection("jdbc:default:connection:");
// create a stored context and store the result set in it
StoredCtx ctx=new StoredCtx(rset);
// register stored context with cartridge services
int key;
try {
   key = ContextManager.setContext(ctx);
} catch (CountException ce) {
   return ERROR;
}
// create a StockPivotImpl instance and store the key in it
Object[] impAttr = new Object[1];
impAttr[0] = new BigDecimal(key);
StructDescriptor sd = new StructDescriptor("STOCKPIVOTIMPL",conn);
sctx[0] = new STRUCT(sd,conn,impAttr);
return SUCCESS;
  }
  public BigDecimal ODCITableFetch(BigDecimal nrows, ARRAY[] outSet)
throws SQLException
  {
Connection conn = DriverManager.getConnection("jdbc:default:connection:");
// retrieve stored context using the key
StoredCtx ctx;
try {
   ctx=(StoredCtx)ContextManager.getContext(key.intValue());
} catch (InvalidKeyException ik ) {
   return ERROR;
}
// get the nrows parameter, but return up to 10 rows
int nrowsval = nrows.intValue();
if (nrowsval>10) nrowsval=10;
// create a vector for the fetched rows
Vector v = new Vector(nrowsval);
int i=0;
StructDescriptor outDesc =
   StructDescriptor.createDescriptor("TICKERTYPE", conn);
Object[] out_attr = new Object[3];
while(nrowsval>0 && ctx.rset.next()){
   out_attr[0] = (Object)ctx.rset.getString(1);
   out_attr[1] = (Object)new String("O");
   out_attr[2] = (Object)new BigDecimal(ctx.rset.getFloat(2));
   v.add((Object)new STRUCT(outDesc, conn, out_attr));
   out_attr[1] = (Object)new String("C");
   out_attr[2] = (Object)new BigDecimal(ctx.rset.getFloat(3));
   v.add((Object)new STRUCT(outDesc, conn, out_attr));
   i+=2;
   nrowsval-=2;
}
// return if no rows found
if(i==0) return SUCCESS;
// create the output ARRAY using the vector
Object out_arr[] = v.toArray();
ArrayDescriptor ad = new ArrayDescriptor("TICKERTYPESET",conn);
outSet[0] = new ARRAY(ad,conn,out_arr);
return SUCCESS;
  }
  public BigDecimal ODCITableClose() throws SQLException {
// retrieve stored context using the key, and remove from ContextManager
StoredCtx ctx;
try {
   ctx=(StoredCtx)ContextManager.clearContext(key.intValue());
} catch (InvalidKeyException ik ) {
   return ERROR;
}
// close the result set
Statement stmt = ctx.rset.getStatement();
ctx.rset.close();
if(stmt!=null) stmt.close();
return SUCCESS;
  }
}
所有这些之后，为了拥有可用于创建上述表类型的表的 流水线函数 ，我们需要具有 ref游标 和 流水线函数本身
。我已将ref游标放入包中。
-- Define the ref cursor type
  CREATE OR REPLACE PACKAGE refcur_pkg IS
TYPE refcur_t IS REF CURSOR RETURN StockTable%ROWTYPE;
  END refcur_pkg;
/
  -- Create table function
  CREATE OR REPLACE FUNCTION StockPivot(p refcur_pkg.refcur_t) RETURN TickerTypeSet
  PIPELINED USING StockPivotImpl;
/
我的问题是，如何调用StockPivot函数以执行JSP并显示所提到类型的表。
我期望从模拟表的简单选择中得到一个结果：
-----------------------------
|  column1 |  column2 | ... |
|---------------------------|
| row_data1| row_data2| ... |
| --------------------------|
|___________________________|
我试图这样调用该函数，但是由于 明显的 原因（我们需要使用ref游标作为参数），它无法正常工作：
SELECT * FROM TABLE(StockPivot());
先感谢您。

解决方案:

Oracle SQL-如何使用JSP调用ODCI流水线函数

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