SQL is used to select required columns from required rows. The data rows don’t have row_names unless you’ve defined a column with the name row_names (this is not done as a rule). At a basic level, retrieving data from an RDBMS is through an SQL statement that is constructed as follows: (This’d be a SELECT statement. The simplest version has the following clauses)

1. Pick the table which holds the data of interest (FROM clause). If we want telephone listings, we might query the whitepages table.
2. Identify the rows which hold the data of interest (WHERE clause). This is done by putting conditions on column values (there are no row hearders or row names). We want phone numbers for people whose last name is “Hemingway” Here the last name would be a column in the table, not the row name.
3. Pick the data columns we want to retrieve (SELECT clause). We want the first name, last name and phone number.

Putting it all together, we might have:

SELECT
    first_name,
    last_name,
    phone_number
FROM
    state
WHERE
    (last_name = "sam")