The code below works properly and shows me a list of databases in my database. In the code given below, What is TABLE_CAT and Why is it there ?
import java.sql.*;
public class Database{
public static void main(String [] args) {
Connection con = null;
try {
con = DriverManager.getConnection("jdbc:mysql://localhost:3306","cowboy","123456");
DatabaseMetaData meta = con.getMetaData();
ResultSet res = meta.getCatalogs();
System.out.println("List of databases: ");
while (res.next()) {
System.out.println(" " + res.getString("TABLE_CAT"));
}
res.close();
con.close();
} catch (SQLException e) {
System.err.println("SQLException: " + e.getMessage());
}
}
}
TABLE_CAT is the name of the column in your resutSet. As you are iterating over your result set row by row, using res.getString("TABLE_CAT"))
allows you to extract the value from that column in the current result row. As meta.getCatalogs()
returns catalog names available in a database, the catalog name is then stored under a column called TABLE_CAT.
This should make more sense to you now.
TABLE CATEGORY
??
It's a simple key that can be used to extract values from the resultSet
of the meta-data
You can use the ResultSetMetaData
(that can be obtained from the ResultSet
) to list all the column names available within the ResultSet
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