(PHP 4 >= 4.3.0, PHP 5)
pg_select — 选择记录
$connection
, string $table_name
, array $assoc_array
[, int $options = PGSQL_DML_EXEC
] )pg_select() 根据 assoc_array 数组中的 field=>value 值来选择记录。成功的查询返回和 assoc_array 指定的条件相匹配的包括记录和字段的数组。
如果指定了 options， pg_convert() 会按照指定选项作用于 assoc_array 之上。
此函数是实验性的。此函数的表象，包括名称及其相关文档都可能在未来的 PHP 发布版本中未通知就被修改。使用本函数风险自担 。
connection
PostgreSQL 数据库连接资源。
table_name
Name of the table from which to select rows.
assoc_array
An array whose keys are field names in the table table_name,
and whose values are the conditions that a row must meet to be retrieved.
options
Any number of PGSQL_CONV_FORCE_NULL,
PGSQL_DML_NO_CONV,
PGSQL_DML_EXEC,
PGSQL_DML_ASYNC or
PGSQL_DML_STRING combined. If PGSQL_DML_STRING is part of the
options then query string is returned.
成功时返回 TRUE， 或者在失败时返回 FALSE。 Returns string if PGSQL_DML_STRING is passed
via options.
Example #1 pg_select() example
<?php
$db = pg_connect('dbname=foo');
// This is safe, since $_POST is converted automatically
$rec = pg_select($db, 'post_log', $_POST);
if ($rec) {
echo "Records selected\n";
var_dump($rec);
} else {
echo "User must have sent wrong inputs\n";
}
?>
wietse at cj2 dot nl (2006-02-27 08:20:18)
David mentioned that you can't do a Select all.
However, when executing this script:
<?php
$conn_string = "dbname=mydb";
$db = pg_connect($conn_string);
$selectfields = array("imgid" => "");
$records = pg_select($db,"mmsfiles",$selectfields);
print_r($records);
?>
...I get this result:
Array
(
[0] => Array
(
[imgid] => 1
[file] => /home/wietse/public_html/mms/images/1.gif
[thumb] =>
)
[1] => Array
(
[imgid] => 2
[file] => /home/wietse/public_html/mms/images/2.gif
[thumb] =>
)
[2] => Array
(
[imgid] => 3
[file] => /home/wietse/public_html/mms/images/3.gif
[thumb] =>
)
[3] => Array
(
[imgid] => 4
[file] => /home/wietse/public_html/mms/images/4.gif
[thumb] =>
)
)
david dot tulloh at infaze dot com dot au (2005-05-16 21:46:46)
Valid options are PGSQL_DML_NO_CONV, PGSQL_DML_EXEC, PGSQL_DMP_ASYNC, PGSQL_DML_STRING (pulled out of source code).
This function does not support selecting from multiple tables. You can get around this by setting the PGSQL_DML_NO_CONV option. This prevents the error which occurs when the function tries to convert the condition array.
I think it is also important to point out that the table_name field is not safe, particularily with the PGSQL_DML_NO_CONV option.
The arguements array field is compulsory, as documented. What isn't so clear is that the array has to actually have some values in it, you can't do a select all.
In summary, this function is good for a very small subset of basic queries. If you are after anything more complex you are better off with pg_query.