Question

I am using Oracle Express Edition and I want to get table information (column name,type,size,etc..) programmatically , inside my program (.Net C#, Microsoft oracle connector).

In SqlPlus, when i give command “desc <tablename>” it works perfectly and print all information about table.

Now i want to do it programmatically. I tried to give query “desc <tablename>” but it failed. Then i read somewhere that desc is a stored procedure and we have to call it as a stored procedure,then i tried following code, its failing with error,

Code 1

private OracleDataReader OracleDescribe(string tablename)
{
    OracleCommand cmd = new OracleCommand("describe " + tablename, OracleConn);
    return cmd.ExecuteReader();
}

Error 1

Invalid SQL Statement

Code 2

private OracleDataReader OracleDescribe(string tablename)
{
    OracleCommand cmd = new OracleCommand("describe", OracleConn);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.Add("table", OracleType.VarChar).Value = tablename;
    return cmd.ExecuteReader();
}

Error 2

Encountered the symbol ">" when expecting one of the following: (

Answer 1

Use a query on the system’s meta-data views/tables. E.g.:

SELECT TABLE_NAME, COLUMN_NAME, DATA_TYPE, DATA_LENGTH, 
       DATA_PRECISION, DATA_SCALE, NULLABLE, DATA_DEFAULT, CHAR_LENGTH 
FROM ALL_TAB_COLUMNS 
WHERE OWNER='SCOTT' AND TABLE_NAME IN ('EMP', 'DEPT') 
ORDER BY TABLE_NAME ASC, COLUMN_ID ASC

You could also look into the GetSchema method on DbConnection, (if you’re using .NET 2.0 or higher, recommended), and check the specific views defined in the MSDN.