PHP MYSQL 如果存在则更新或如果不存在则插入？

Question

我不知道这是否完全正确。我有一个类，如果字段当前存在我想更新数据库，如果不存在则插入。复杂的是我正在连接 3 个表(set_colors、school_art、baseimage)

任何帮助都会很棒。

这是我的:

public function set_layer_colors($value) {
    global $db;

    $result_array = mysql_query("
    IF EXISTS(SELECT * FROM set_colors WHERE school_art_id = '{$value}')

      UPDATE set_colors (school_art_id, baseimage_id, sub_folder, layer)
        SELECT school_art.id, baseimage.id, baseimage.sub_folder, baseimage.layer
        FROM school_art 
        JOIN baseimage ON baseimage.base_folder = school_art.series_code 
        WHERE baseimage.image_type = 'B' ORDER BY school_art.id 

    ELSE

     INSERT INTO set_colors (school_art_id, baseimage_id, sub_folder, layer)
        SELECT school_art.id, baseimage.id, baseimage.sub_folder, baseimage.layer
        FROM school_art 
        JOIN baseimage ON baseimage.base_folder = school_art.series_code 
        WHERE baseimage.image_type = 'B' ORDER BY school_art.id 
        ");

    return $result_array;
}

Answer 1

我相信您正在寻找以下语法:

INSERT INTO <table> (field1, field2, field3, ...) 
VALUES ('value1', 'value2','value3', ...)
ON DUPLICATE KEY UPDATE
field1='value1', field2='value2', field3='value3', ...

Note: With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values.

MySQL 文档:INSERT ... ON DUPLICATE KEY UPDATE Statement