Query Command in JDBC

hi, everybody
now, for try to finish a project about house query, u know, there have many fields(information) about the house, as well as the hourse owner's information.
suppose u want to know the price, address, facilities and the owner's information, u must use the select command to join two or three different tables, and possibly there have more than 256 sentences about the select command, wow, too much?
so, how can i make anothre ways to finish this problem.
please help me!

One way to control a database when the are a 'lot' of attributes is to create a named attribute table. So instead of this
table X - fields: name, color, width, height, finish, texture, cost
data X
         bear, brown,       14, 14, shiny, fuzzy, $14
         top, red and blue, 3, 3, shiny, hard, $1
.one uses this
table X - fields: name, id, cost
table Attr - fields: X_id, name, value
Data X
         bear, 1, $14
         top, 2, $1
Data Y
         1, color, brown
         1, width, 14
         1, height, 14
         1, finish, shiny
         1, texture, fuzzy
         2, color, red and blue
         2, width, 3
         2, height, 3
         2, finish, shiny
         2, texture, hard
     The trade off is ease of use in programming vs more complex logic and possibly more storage space (noting that name in Y could be a number saves on space.)
This might actually result in saving space if the attribute values are sparse - not all of them have values.
This can slow down searches and make queries slower. But that greatly depends on the query. There are cases where this can make it substantially faster. That depends on the nature of the data and the needed queries.
An alternative to this is to make a table for each attribute. Once again there are trade offs there. And it probably isn't applicable for 'attributes for a house'.
Notice in the above that cost is not part of the attribute table. This is a design decision that once again is driven by the needed queries. Presumably cost is an important query item, it will always exist and will always be returned for any query. So it can remain in the main table.
An additional table can be used - an attribute name table. Doing this, and writing code which supports the use of that makes it extremely easy to add new attributes.

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Confirmed.
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Refer to note 841704 if you face any issue while executing OS command in JDBC adapter.
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Edited by: Farooq Farooqui on Jan 16, 2009 11:36 AM

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hi all,
I have the following code in a Java program
try
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I'm trying to track my license usage (to better determine when to buy new licenses, and to track usage over time).
When I issue the 'tarantella license query command, this is typical of the output I see:
[root@sgdserver ~]# /opt/tarantella/bin/tarantella license query
License usage at: Mon Feb 11 14:03:53 EST 2008
Type                In use / Total
Base                6      / 230
UNIX                4      / 230
Mainframe           0      / 230
Windows             0      / 230
AS/400              0      / 230
[root@sgdserver ~]#What is the above saying? Is it saying that I am using 10 licenses out of my 230, or am I just using 6 licenses? In other words, do I add up the numbers or just use the highest one? Or do I just have to worry about the 'Base' license number?
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Hi everybody
I am new to Oracle and SPARQL, so I'm sorry if my question is the elementry one!
select s, p, o from table(SEM_MATCH( '(?s ?p ?o) (?s <htt...> ?o) ', SEM_Models('OWlTEST'), null, null, null ))
I have an SPARQL command which runs on Oracle correctly and returns 8 Rows. So far so good!
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Sara,
I don't know about SPARQL not about jena, but for Java you need to change:
{code}
if (rs.next()) {..
{code}
to
{code}
while (rs.next()) {..
{code}
Otherwise you just fech and see only first row.
Look at : http://www.java2s.com/Code/JavaAPI/java.sql/ResultSetnext.htm
HTH
Thomas

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Sounds like a good idea but then you would need an external db and update the table in a thread safe way !.
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Swatantra,
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raj.

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according to your answer, is it safe to say that we
should NOT
handle transaction control in both query and JDBC
call? i am on the side of JDBC
program control. However our manager feels that if we
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http://searchsap.techtarget.com/tip/0,289483,sid21_gci1246926,00.html#
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My JDBC code is below:
Thanks.
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One way to control a database when the are a 'lot' of attributes is to create a named attribute table. So instead of this
table X - fields: name, color, width, height, finish, texture, cost
data X
         bear, brown,       14, 14, shiny, fuzzy, $14
         top, red and blue, 3, 3, shiny, hard, $1
.one uses this
table X - fields: name, id, cost
table Attr - fields: X_id, name, value
Data X
         bear, 1, $14
         top, 2, $1
Data Y
         1, color, brown
         1, width, 14
         1, height, 14
         1, finish, shiny
         1, texture, fuzzy
         2, color, red and blue
         2, width, 3
         2, height, 3
         2, finish, shiny
         2, texture, hard
     The trade off is ease of use in programming vs more complex logic and possibly more storage space (noting that name in Y could be a number saves on space.)
This might actually result in saving space if the attribute values are sparse - not all of them have values.
This can slow down searches and make queries slower. But that greatly depends on the query. There are cases where this can make it substantially faster. That depends on the nature of the data and the needed queries.
An alternative to this is to make a table for each attribute. Once again there are trade offs there. And it probably isn't applicable for 'attributes for a house'.
Notice in the above that cost is not part of the attribute table. This is a design decision that once again is driven by the needed queries. Presumably cost is an important query item, it will always exist and will always be returned for any query. So it can remain in the main table.
An additional table can be used - an attribute name table. Doing this, and writing code which supports the use of that makes it extremely easy to add new attributes.

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Hi,
But the Runtime.exec() and the JDBC application have
their own connection to the database, and the sqlplus
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try
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection(dsn,"guest","guest");
OR DriverManager.getConnection(dsn);
System.out.println("Conection's opened");
catch(ClassNotFoundException cnfe)
System.err.println(cnfe);
catch(SQLException sqle)
System.err.println(sqle);
try that code and double check you DSN Name . it's a good practice to greate a system DSN.
i hope that helps.
FEEL FREE TO ASK. WON'T BITE U
ABDUL

Query Command in JDBC

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