如何在MySQL中更新多行并左填充值？

使用LPAD()函数来左填充值。我们首先创建一个表 –

mysql> create table DemoTable
   -> (
   -> Number int
   -> );
Query OK, 0 rows affected (2.26 sec

使用insert命令将一些记录插入表中 –

mysql> insert into DemoTable values(857786);
Query OK, 1 row affected (0.26 sec)

mysql> insert into DemoTable values(89696);
Query OK, 1 row affected (0.16 sec)

mysql> insert into DemoTable values(89049443);
Query OK, 1 row affected (0.25 sec

使用select语句从表中显示所有记录 –

mysql> select *from DemoTable;

阅读更多：MySQL 教程

输出

这将产生以下输出 –

+----------+
| Number   |
+----------+
| 857786   |
| 89696    |
| 89049443 |
+----------+
3 rows in set (0.00 sec)

以下是更新多行并左填充值的查询 –

mysql> update DemoTable set Number=LPAD(Number, 7, "9") where length(Number) < 7;
Query OK, 2 rows affected (0.40 sec)
Rows matched: 2 Changed: 2 Warnings: 0

让我们再次检查表记录 –

mysql> select *from DemoTable;

输出

这将产生以下输出 –

+----------+
| Number   |
+----------+
| 9857786  |
| 9989696  |
| 89049443 |
+----------+
3 rows in set (0.00 sec)