带有数组字段 PostgreSQL 和 PHP 的准备好的语句

Question

有下表：

CREATE TABLE submission (
    num SERIAL,
    user_id INTEGER NOT NULL,
    assignment_id INTEGER NOT NULL,
    timestamp TIMESTAMP,
    lti_info TEXT[][],
    PRIMARY KEY(num),
    FOREIGN KEY (user_id) REFERENCES canvas_user,
    FOREIGN KEY (assignment_id) REFERENCES assignment
);

我想用 php 函数在桌子上进行 INSERT，类似于以下（不工作）代码：

function create_submission($user_id, $assignment_id, $lti_info) {
        # INSERT everything except lti info
        $query = "INSERT INTO submission (user_id, assignment_id, timestamp) VALUES ($1, $2, LOCALTIMESTAMP) RETURNING num";
        pg_prepare($this->con, "createsub", $query);
        $rs = pg_execute($this->con, "createsub", array($user_id, $assignment_id));
        $row = pg_fetch_row($rs);
        $sub_num = $row[0];

        # update table to insert lti_info
        $serialized = serialize($lti_info);
        $query = "UPDATE submission SET lti_info = $1";
        pg_prepare($this->con, "insertlti", $query);
        pg_execute($this->con, "insertlti", array($serialized));
        return $sub_num;
    }

我曾尝试对类似问题进行序列化并执行类似此答案的操作：Supply a prepared statement with an array，但没有成功。

如果你们中的任何人能提供 create_submission 函数的解决方案，我将非常高兴。

更新：

当我执行 create_submission 时，它会在更新点出现以下错误：

pg_execute()：查询失败：错误：数组值必须以“{”或 维度信息

lti_info 是字符串的关联数组，类似于：

lti_info = array (
"oauth_consumer_key" => "example",
"oauth_consumer_secret" => "secret"
)

注意：我不介意一切都是在一次插入中完成的，还是先插入“正常”字段然后再插入 lti_info 数组。

Answer 1

Postgresql 中没有关联数组。要将其保存为二维数组，有必要构建一个合适的字符串以传递给 Postgresql 并在返回时执行相反的操作。保存为 JSON 更简单：

create table submission (
    num serial,
    user_id integer not null,
    assignment_id integer not null,
    timestamp timestamp,
    lti_info json,
    primary key(num)
);

使用json_encode

<?php
$lti_info  = array (
    "oauth_consumer_key" => "example",
    "oauth_consumer_secret" => "secret"
);

$query = "
    insert into submission (user_id, assignment_id, timestamp, lti_info) values
    ($1, $2, localtimestamp, $3)
    returning num
";

$conn = pg_connect ( "port=5432 user=cpn dbname=cpn");
pg_prepare($conn, "createsub", $query);
pg_execute($conn, "createsub", array(1, 1, json_encode($lti_info)));

$query = "select * from submission";
pg_prepare($conn, "select", $query);
$rs = pg_execute($conn, "select", array());

$lti_info = (array) json_decode(pg_fetch_result($rs, "lti_info"));

print_r ($lti_info);
?>

输出

    Array
(
    [oauth_consumer_key] => example
    [oauth_consumer_secret] => secret
)