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Posted to derby-user@db.apache.org by Yan Ma <po...@yahoo.com.cn> on 2006/03/26 05:02:19 UTC
回复: Re: How to get call a java procedure that returns a value?
Many thanks for your reply!
However I may not present my question clearly.
In derby 10.1, we usually get returned values through OUT parameters.
My question is can we get a return value through the java methods' return value?
1. I wrote a simple JAVA METHOD that RETURNS a int value:
public class Simple {
public static int returnint(int id){
return id * id;
}
}
2. Generated a jar file, installed it and modified database classpath.
3. Created a procedure named RETURNINT like the following:
CREATE PROCEDURE RETURNINT (IN ID INTEGER) PARAMETER STYLE JAVA LANGUAGE JAVA MODIFIES SQL DATA EXTERNAL NAME 'Simple.returnint';
4. Invoked it from java code:
// invoke the procedure RETURNINT, expected result is 2*2 = 4.
callStmt = con.prepareCall(? = CALL RETURNINT (2));
5. Then I got the exception:
ERROR 42Y03: 'RETURNINT' is not recognized as a function or procedure.
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.impl.sql.compile.StaticMethodCallNode.bindExpression(Unknown Source)
at org.apache.derby.impl.sql.compile.JavaToSQLValueNode.bindExpression(Unknown Source)
at org.apache.derby.impl.sql.compile.ResultColumn.bindExpression(Unknown Source)
at org.apache.derby.impl.sql.compile.ResultColumnList.bindExpressions(Unknown Source)
at org.apache.derby.impl.sql.compile.RowResultSetNode.bindExpressions(Unknown Source)
at org.apache.derby.impl.sql.compile.DMLStatementNode.bindExpressions(Unknown Source)
at org.apache.derby.impl.sql.compile.DMLStatementNode.bind(Unknown Source)
at org.apache.derby.impl.sql.compile.ReadCursorNode.bind(Unknown Source)
at org.apache.derby.impl.sql.compile.CursorNode.bind(Unknown Source)
at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown Source)
at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown Source)
at org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source)
at com.ibm.wbiserver.relationshipservice.test.TestLoadRelationship.test(TestLoadRelationship.java:322)
at com.ibm.wbiserver.relationshipservice.test.TestLoadRelationship.main(TestLoadRelationship.java:386)
A similar exception happens if I run the code:
callStmt = con.prepareCall(? = CALL APP.RETURNINT (2));
I have checked sys.sysaliases, sys.sysfiles, my jar file and procedure do exist.
Rajesh Kartha <ka...@gmail.com> 写道:
Here is a very simple example of returning an INT from a Java Stored
Procedure:
In this case, the SP takes in an int and adds '100' to it.
Implementation:
---------------
public class MyProc {
public static void retIntegerValue(int i1[], int i3) {
i1[0]=i3+100;
}
}
Creating the Stored Procedure:
-------------------------------
drop procedure retIntVal;
CREATE PROCEDURE retIntVal(OUT a INT, IN b INT) PARAMETER STYLE JAVA
LANGUAGE JAVA EXTERNAL NAME 'MyProc.retIntegerValue';
Invoking it from your code:
----------------------------
CallableStatement op1 = connCS.prepareCall("CALL retIntVal(?, ?)");
op1.registerOutParameter(1, Types.INTEGER); //Important
op1.setInt(2,24); //Provide the input value
op1.execute();
int newi=op1.getInt(1);
System.out.println("New Int value = "+newi);
Output:
--------
New Int value = 124
More info available at:
http://wiki.apache.org/db-derby/DerbyInstruction
HTH
-Rajesh
Yan Ma wrote:
> Thx!
>
> ------------------
> 马燕
>
> 中科院软件所
> 通用软件实验室
>
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