postgresql “数组推送”的 Postgres 数组附加和数组长度
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Postgres Array Append & Array Length for 'Array Push'
提问by mu is too short
What is the best way to add an element to an array when the size of the array is not provided?
当未提供数组的大小时，将元素添加到数组的最佳方法是什么？
With array_appendthis is what I can think of:
随着array_append这是我能想到的：
UPDATE table SET array = array_append((SELECT array FROM table WHERE ...), 'element') WHERE ...;
With array_lengththis is what I can think of:
随着array_length这是我能想到的：
UPDATE table SET array[array_length((SELECT array FROM table WHERE ...), 1)+1] = element;
回答by mu is too short
The simplest thing would be:
最简单的事情是：
update table
set array = array_append(array, 'element')
where ...
or perhaps use the ||operator:
或者使用||运算符：
update table
set array = array || 'element'
where ...
Both of those are equivalent to the more common set n = n + 11for numbers.
这两个都相当于更常见set n = n + 11的数字。
