How to Fetch Data Using Embedded SQL

Fetching data in embedded SQL is done using the SELECT statement. There are two cases:

• The SELECT statement returns at most one row – Use an INTO clause to assign the returned values directly to host variables.
• The SELECT statement may return multiple rows – Use cursors to manage the rows of the result set.

• SELECT Statements That Return at Most One Row
  A single row query retrieves at most one row from the database. A single-row query SELECT statement has an INTO clause following the SELECT list and before the FROM clause. The INTO clause contains a list of host variables to receive the value for each SELECT list item. There must be the same number of host variables as there are SELECT list items. The host variables may be accompanied by indicator variables to indicate NULL results.
• Cursors in Embedded SQL
  A cursor is used to retrieve rows from a query that has multiple rows in its result set. A cursor is a handle or an identifier for the SQL query and a position within the result set.
• Wide Fetches or Array Fetches
  The FETCH statement can be modified to fetch more than one row at a time, which may improve performance. This is called a wide fetch or an array fetch.