wordpress函数check_column()用法示例

check_column( string $table_name,  string $col_name,  string $col_type,  bool $is_null = null,  mixed $key = null,  mixed $default = null,  mixed $extra = null )

Check column matches criteria.

描述

Uses the SQL DESC for retrieving the table info for the column. It will help understand the parameters, if you do more research on what column information is returned by the SQL statement. Pass in null to skip checking that criteria.

Column names returned from DESC table are case sensitive and are listed: Field Type Null Key Default Extra

参数

$table_name

(string)
(Required)
Table name

$col_name

(string)
(Required)
Column name

$col_type

(string)
(Required)
Column type

$is_null

(bool)
(Optional)
Check is null.

Default value: null

$key

(mixed)
(Optional)
Key info.

Default value: null

$default

(mixed)
(Optional)
Default value.

Default value: null

$extra

(mixed)
(Optional)
Extra value.

Default value: null

返回值

(bool) True, if matches. False, if not matching.

源代码

File: wp-admin/install-helper.php

function check_column($table_name, $col_name, $col_type, $is_null = null, $key = null, $default = null, $extra = null) {
	global $wpdb;
	$diffs = 0;
	$results = $wpdb->get_results("DESC $table_name");

	foreach ($results as $row ) {

		if ($row->Field == $col_name) {

			// Got our column, check the params.
			if (($col_type != null) && ($row->Type != $col_type)) {
				++$diffs;
			}
			if (($is_null != null) && ($row->Null != $is_null)) {
				++$diffs;
			}
			if (($key != null) && ($row->Key  != $key)) {
				++$diffs;
			}
			if (($default != null) && ($row->Default != $default)) {
				++$diffs;
			}
			if (($extra != null) && ($row->Extra != $extra)) {
				++$diffs;
			}
			if ($diffs > 0) {
				return false;
			}
			return true;
		} // end if found our column
	}
	return false;
}

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相关函数

Uses

• wp-includes/wp-db.php:
  wpdb::get_results()

User Contributed Notes