Results from a SELECT statement or a CALL statement are put into either the variables in the variable list or the program
data areas described by the named SQLDA. The correspondence is one-to-one from the OUTPUT (selection list or parameters) to
either the host variable list or the SQLDA descriptor array.
If EXECUTE INTO is used with an INSERT statement, the inserted row is returned in the second descriptor. For example,
when using auto-increment primary keys or BEFORE INSERT triggers that generate primary key values, the EXECUTE statement provides
a mechanism to re-fetch the row immediately and determine the primary key value that was assigned to the row. The same thing
can be achieved by using @@identity with auto-increment keys.
The optional ARRAY clause can be used with prepared INSERT statements to allow wide inserts, which insert more than one
row at a time and which can improve performance. The integer value is the number of rows to be inserted. The SQLDA must contain
a variable for each entry (number of rows * number of columns). The first row is placed in SQLDA variables 0 to (columns per
row)-1, and so on.
The EXECUTE statement can be used for any SQL statement that can be prepared. Cursors are used for SELECT statements or CALL
statements that return many rows from the database. See Using cursors in embedded SQL.
After successful execution of an INSERT, UPDATE or DELETE statement, the sqlerrd field of the SQLCA (SQLCOUNT) is filled in with the number of rows affected by the operation.
Execute the named dynamic statement, which was previously prepared. If the dynamic statement contains host variable place
holders which supply information for the request (bind variables), either the sqlda-name must specify a C variable which is a pointer to a SQLDA containing enough descriptors for all the bind variables occurring
in the statement, or the bind variables must be supplied in the hostvar-list.
A short form to PREPARE and EXECUTE a statement that does not contain bind variables or output. The SQL statement contained
in the string or host variable is immediately executed, and is dropped on completion.
The EXECUTE statement comprises part of optional SQL language feature B031, "Basic dynamic SQL", of the SQL/2008 standard.
The INTO clause is part of optional language feature B032, "Extended dynamic SQL". The ARRAY clause is a vendor extension.
The EXECUTE IMMEDIATE statement supported with embedded SQL is also part of optional SQL language feature B031.