Any SQL command can be run from within an embedded SQL application. Below are some examples of how to do that.
Creating a table:
EXEC SQL CREATE TABLE foo (number integer, ascii char(16)); EXEC SQL CREATE UNIQUE INDEX num1 ON foo(number); EXEC SQL COMMIT;
Inserting rows:
EXEC SQL INSERT INTO foo (number, ascii) VALUES (9999, 'doodad'); EXEC SQL COMMIT;
Deleting rows:
EXEC SQL DELETE FROM foo WHERE number = 9999; EXEC SQL COMMIT;
Single-row select:
EXEC SQL SELECT foo INTO :FooBar FROM table1 WHERE ascii = 'doodad';
Select using cursors:
EXEC SQL DECLARE foo_bar CURSOR FOR SELECT number, ascii FROM foo ORDER BY ascii; EXEC SQL OPEN foo_bar; EXEC SQL FETCH foo_bar INTO :FooBar, DooDad; ... EXEC SQL CLOSE foo_bar; EXEC SQL COMMIT;
Updates:
EXEC SQL UPDATE foo SET ascii = 'foobar' WHERE number = 9999; EXEC SQL COMMIT;
The tokens of the form
:
are
host variables, that is, they refer to
variables in the C program. They are explained in Section 31.6, “Using Host Variables”.
something
In the default mode, statements are committed only when
EXEC SQL COMMIT
is issued. The embedded SQL
interface also supports autocommit of transactions (similar to
libpq behavior) via the -t
command-line
option to ecpg
(see below) or via the EXEC SQL
SET AUTOCOMMIT TO ON
statement. In autocommit mode, each
command is automatically committed unless it is inside an explicit
transaction block. This mode can be explicitly turned off using
EXEC SQL SET AUTOCOMMIT TO OFF
.