CODEWITHSUNDEEP
javamysqlsqljdbc
Hudson Worden
Hudson Worden

Reputation: 2353

MySQL Java JDBC: How to get the name of an auto-incremented column?

I'm working on a program that makes using MySQL databases simpler. Right now I have to create forms to add and edit data from the tables within the database. The problem is that when I create the form I don't want to display fields for auto-incremented columns. All I need is the name of the column to fix this but I have no idea how to find the name of a auto-incremented column. I have tried looking up the answer but all I find is information about finding auto - generated keys. Can someone help me or point me in the right direction? Thanks for the help.

UPDATE: Thanks for the help. Base on the answers below I came up with this method:

public Vector<String> getAutoIncrementedColumns(String table) {
    Vector<String> columnNames = new Vector<String>();
    Connection connection;
    try {
        connection = DriverManager.getConnection(getUrl(), getUser(),
                    getPassword());
        Statement statement = connection.createStatement();
        ResultSet result = statement.executeQuery("Select * from "+table);
        int columnCount = result.getMetaData().getColumnCount();
        for(int i = 1; i <=columnCount; i++){
            if(result.getMetaData().isAutoIncrement(i)){
                columnNames.add(result.getMetaData().getColumnName(i));
            }
        }

    } catch (SQLException e) {

        e.printStackTrace();
    }


    return columnNames;
}

Upvotes: 3

Views: 1872

Answers (4)

powerMicha
powerMicha

Reputation: 2773

If you have access to the schema information_schema these informations are available from the tables

  • TABLES (column: auto_increment, 0 = no, 1 = yes)
  • COLUMNS (column: extra = auto_increment for the specific column)

Upvotes: 0

hage
hage

Reputation: 6153

The class ResultSetMetaData can provide this information.

But you would have to execute a select * first to get a result set. You could do 

SELECT * FROM table LIMIT 1

to get the result set.

Upvotes: 0

Jason Day
Jason Day

Reputation: 8839

Once you have a ResultSet, you can call its getMetaData method to the get a ResultSetMetaData object. From there, you can use the isAutoIncrement method to determine if a column is an AUTO_INCREMENT column, and getColumnName to get the column's name.

Upvotes: 4

Nivas
Nivas

Reputation: 18334

The EXTRA column of the INFORMATION_SCHEMA.COLUMNS table should have this information.

PS:this is from top of my head. Don't have MySql handy, you may have to test to confirm.

Upvotes: 1

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