{"id":1264,"date":"2018-01-19T19:22:37","date_gmt":"2018-01-19T19:22:37","guid":{"rendered":"http:\/\/goofy-trucks.flywheelsites.com\/phplib-and-multiple-databases-page-3\/"},"modified":"2018-01-19T19:24:39","modified_gmt":"2018-01-19T19:24:39","slug":"phplib-and-multiple-databases-page-3","status":"publish","type":"post","link":"https:\/\/phpbuilder.com\/phplib-and-multiple-databases-page-3\/","title":{"rendered":"PHPLib and Multiple Databases Page 3"},"content":{"rendered":"
\n
\n
By Peter Moulding<\/div>\n
on November 7, 2000<\/div>\n<\/p><\/div>\n
\n

Expanding PHPLIB<\/h2>\n
\n PHPLIB accesses databases through an object created from class DB_Sql.
\n Db_mysql.inc includes the DB_Sql class as modified for MySQL. We will
\n extend DB_Sql by adding code to common.php3, after the line that includes
\n db_mysql.inc.<\/div>\n
\n DB_Sql contains many functions to perform queries. The one we want to
\n change is:<\/div>\n
\n<\/p>\n

<?php<\/p>\n

\u00a0<\/span>\/*\u00a0public:\u00a0connection\u00a0management\u00a0*\/
\n
<\/span>function\u00a0<\/span>connect<\/span>(<\/span>$Database\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$Host\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$User\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$Password\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0<\/span>\/*\u00a0Handle\u00a0defaults\u00a0*\/
\n
\u00a0\u00a0\u00a0\u00a0<\/span>if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Database<\/span>)
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Database\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Database<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Host<\/span>)
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Host\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Host<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$User<\/span>)
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$User\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>User<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Password<\/span>)
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Password\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Password<\/span>;
\n
\u00a0
\n
\u00a0\u00a0\u00a0\u00a0<\/span>\/*\u00a0establish\u00a0connection,\u00a0select\u00a0database\u00a0*\/<\/p>\n

\u00a0\u00a0\u00a0\u00a0<\/span>if\u00a0(\u00a0<\/span>0\u00a0<\/span>==\u00a0<\/span>$this<\/span>-><\/span>Link_ID\u00a0<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>Link_ID<\/span>=<\/span>mysql_pconnect<\/span>(<\/span>$Host<\/span>,\u00a0<\/span>$User<\/span>,\u00a0<\/span>$Password<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(!<\/span>$this<\/span>-><\/span>Link_ID<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>halt<\/span>(<\/span>\"pconnect($Host,\u00a0$User,\u00a0$Password)\u00a0failed.\"<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>0<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(!@<\/span>mysql_select_db<\/span>(<\/span>$Database<\/span>,<\/span>$this<\/span>-><\/span>Link_ID<\/span>))\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>halt<\/span>(<\/span>\"cannot\u00a0use\u00a0database\u00a0\"<\/span>.<\/span>$this<\/span>-><\/span>Database<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>0<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0
\n
\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>$this<\/span>-><\/span>Link_ID<\/span>;
\n
}<\/p>\n

<\/span>?>
\n
<\/span>
\n<\/span>
\n<\/code><\/font><\/div>\n

\n Find the connect() function in your db_mysql.inc (or the .inc for your
\n database), then copy it in to common.php3 somewhere after the include of
\n db_mysql.inc. You will have to wrap it in a class definition as described
\n at the end of this article.<\/div>\n
\n I find the code hard to read. Therefore, the first thing to do is make the copied code
\n readable:<\/div>\n
\n<\/p>\n

<?php<\/p>\n

<\/span>\/*\u00a0public:\u00a0connection\u00a0management\u00a0*\/<\/p>\n

<\/span>function\u00a0<\/span>connect<\/span>(<\/span>$Database\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$Host\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$User\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>,\u00a0<\/span>$Password\u00a0<\/span>=\u00a0<\/span>\"\"<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0<\/span>\/*\u00a0Handle\u00a0defaults\u00a0*\/
\n
\u00a0\u00a0\u00a0\u00a0<\/span>if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Database<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Database\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Database<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Host<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Host\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Host<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$User<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$User\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>User<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0if\u00a0(<\/span>\"\"\u00a0<\/span>==\u00a0<\/span>$Password<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$Password\u00a0<\/span>=\u00a0<\/span>$this<\/span>-><\/span>Password<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0<\/span>\/*\u00a0establish\u00a0connection,\u00a0select\u00a0database\u00a0*\/
\n
\u00a0\u00a0\u00a0\u00a0<\/span>if\u00a0(\u00a0<\/span>0\u00a0<\/span>==\u00a0<\/span>$this<\/span>-><\/span>Link_ID\u00a0<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>Link_ID<\/span>=<\/span>mysql_pconnect<\/span>(<\/span>$Host<\/span>,\u00a0<\/span>$User<\/span>,\u00a0<\/span>$Password<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(!<\/span>$this<\/span>-><\/span>Link_ID<\/span>)\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>halt<\/span>(<\/span>\"pconnect($Host,\u00a0$User,\u00a0$Password)\u00a0failed.\"<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>0<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(!@<\/span>mysql_select_db<\/span>(<\/span>$Database<\/span>,<\/span>$this<\/span>-><\/span>Link_ID<\/span>))\u00a0{
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>$this<\/span>-><\/span>halt<\/span>(<\/span>\"cannot\u00a0use\u00a0database\u00a0\"<\/span>.<\/span>$this<\/span>-><\/span>Database<\/span>);
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>0<\/span>;
\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0}
\n
\u00a0\u00a0\u00a0\u00a0return\u00a0<\/span>$this<\/span>-><\/span>Link_ID<\/span>;
\n
}<\/p>\n

<\/span>?>
\n
<\/span>
\n<\/span>
\n<\/code><\/font><\/div>\n

\n I indented the code so the levels let me match the brackets, with the
\n enclosed code. This avoids errors caused by missing brackets. I added
\n brackets to single lines. PHP lets you get away without brackets around
\n single lines of code after if statements. As soon as you add extra code,
\n the shortcut fails. I suggest always use the brackets to avoid errors when
\n you add code later.<\/div>\n<\/div>\n

<\/p>\n

\n
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Next Page \u00bb<\/a><\/div>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"

By Peter Moulding on November 7, 2000 Expanding PHPLIB PHPLIB accesses databases through an object created from class DB_Sql. Db_mysql.inc includes the DB_Sql class as modified for MySQL. We will extend DB_Sql by adding code to common.php3, after the line that includes db_mysql.inc. DB_Sql contains many functions to perform queries…. <\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1264","post","type-post","status-publish","format-standard","hentry","category-tutorials"],"_links":{"self":[{"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/posts\/1264","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/comments?post=1264"}],"version-history":[{"count":1,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/posts\/1264\/revisions"}],"predecessor-version":[{"id":3157,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/posts\/1264\/revisions\/3157"}],"wp:attachment":[{"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/media?parent=1264"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/categories?post=1264"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phpbuilder.com\/wp-json\/wp\/v2\/tags?post=1264"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}