如何在MySQL中跳过空白和NULL值？

要在MySQL中跳过空白和null，请使用以下语法：

select *from yourTableName where yourColumnName IS NOT NULL AND yourColumnName <> '';

让我们先创建一个表：

mysql> create table DemoTable (Id int, FirstName varchar(20));
Query OK, 0 rows affected (0.66 sec)

以下是使用插入命令将记录插入表中的查询：

mysql> insert into DemoTable values(100,'Larry');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values(101,'');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable values(102,'Chris');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable values(103,null);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values(104,' ');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values(105,'Robert');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable values(106,null);
Query OK, 1 row affected (0.13 sec)

以下是使用select命令从表中显示记录的查询：

mysql> select *from DemoTable;

这将生成以下输出，其中包含空值和NULL：

+------+-----------+
| Id   | FirstName |
+------+-----------+
| 100  | Larry     |
| 101  |           |
| 102  | Chris     |
| 103  | NULL      |
| 104  |           |
| 105  | Robert    |
| 106  | NULL      |
+------+-----------+
7 rows in set (0.00 sec)

以下是跳过MySQL中空值以及null的查询：

mysql> select *from DemoTable where FirstName IS NOT NULL AND FirstName <> '';

这将生成以下输出

+------+-----------+
| Id   | FirstName |
+------+-----------+
| 100  | Larry     |
| 102  | Chris     |
| 105  | Robert    |
+------+-----------+
3 rows in set (0.03 sec)

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