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Let’s say you are running a query and that there is a one-to-many relationship between one of the columns in one table and a column in another table. You could always retrieve the data from the database and process it using a regular programming language, but sometimes you want to do it all on the [...] Read more »

Posted on December 30th, 2008 under SQL, Tip. Comments: None

Let’s say you have two tables in your SQL database. One is called Table1 and has columns called Column1 and Column2. And the other is called Table2 with columns of the same name. An easy way to copy from Table1 to Table2 would be with the following SQL statement.

INSERT INTO Table1
SELECT * FROM Table2

However, let’s [...] Read more »

Posted on November 22nd, 2008 under SQL. Comments: None

Let’s say you have a table in a SQL database and you want to discover the names of the columns from Java. One way to do this that is pretty straightforward is with the following code.

import java.sql.*;
 
…
 
public ArrayList<String> GetColumnNames(String tableName) throws Exception
{
DatabaseMetaData meta = _conn.getMetaData();
ResultSet rsColumns = [...] Read more »

Posted on November 22nd, 2008 under Java, SQL. Comments: None