Database Reference
In-Depth Information
•
: The choices are
INSERT
,
UPDATE
, and
REPLACE
. The most
well-known of these types is the default
INSERT
—using
INSERT
statements
to import back our data. At import time, however, we could be in a situation
where a table already exists and contains valuable data, and we just want
to update the fields that are in the current table we are exporting.
UPDATE
generates statements like
UPDATE
'author'
SET
'id'
=
1,
'name'
=
'John
Smith',
'phone'
=
'111-1111'
WHERE
'id'
=
'1';
updating a row when
the same primary or unique key is found. The third possibility,
REPLACE
,
produces statements like
REPLACE
INTO
'author'
VALUES
(1,
'John
Smith',
'111-1111');
These act like an
INSERT
statement for new rows and
update existing rows, based on primary or unique keys.
Export type
The "Save as ile" subpanel
In the previous examples, the results of the export operation were displayed
on screen, and of course, no compression was made on the data. We can choose to
transmit the export file via HTTP by checking the
Save as file
checkbox. This triggers
a
Save
dialog into the browser, which ultimately saves the file on our local station.
File name template
The name of the proposed file will obey the
File name template
. In this template,
we can use the special __
SERVER__, __DB__
, and
__TABLE__
placeholders. These
placeholders will be replaced by the current server, database, or table name (for
a single-table export). Note that there are two underscore characters before and
after the words. We can also use any special character from the PHP
strftime
function; this is useful for generating an export file based on the current date or hour.
Finally, we can put any other string of characters (not part of the
strftime
special
characters), which will be used literally. The file extension is generated according to
the type of export. In this case, it will be
.sql
. Here are some examples for
the template:
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