coalesce

description

Syntax

coalesce(expr1, expr2, ...., expr_n))

返回参数中的第一个非空表达式（从左向右）

example

1. mysql> select coalesce(NULL, '1111', '0000');
2. +--------------------------------+
3. | coalesce(NULL, '1111', '0000') |
4. +--------------------------------+
5. | 1111                           |
6. +--------------------------------+

keywords

1. COALESCE