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update doc of not|! #1054

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May 7, 2024
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update doc of not|! #1054

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46 changes: 32 additions & 14 deletions docs/MatrixOne/Reference/Operators/operators/logical-operators/not.md
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Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,12 @@

## **运算符说明**

`NOT,!` 逻辑运算符用作于*逻辑非*运算。如果操作数为零，则返回结果为 `true`；如果操作数非零，则返回结果为 `false`；若果操作数为 `NOT NUL` 则返回 `NULL`。
`NOT,!` 逻辑运算符用作于*逻辑非*运算。如果操作数为零，则返回结果为 `true`；如果操作数非零，则返回结果为 `false`；如果操作数为 `NOT NUL` 则返回 `NULL`。

## **语法结构**

```
> SELECT not column_name FROM table_name;
> NOT|! value
```

## **示例**
Expand All @@ -20,16 +20,18 @@ mysql> select not 0;
| true |
+-------+
1 row in set (0.02 sec)
mysql> select not null;
+----------+
| not null |
+----------+
| NULL |
+----------+

mysql> select ! null;
+-------+
| !null |
+-------+
| NULL |
+-------+
1 row in set (0.00 sec)
mysql> select not 1;

mysql> select ! 1;
+-------+
| not 1 |
| !1 |
+-------+
| false |
+-------+
Expand All @@ -39,6 +41,17 @@ mysql> select not 1;
```sql
create table t1 (a boolean,b bool);
insert into t1 values (0,1),(true,false),(true,1),(0,false),(NULL,NULL);
mysql> SELECT * FROM T1;
+-------+-------+
| a | b |
+-------+-------+
| false | true |
| true | false |
| true | true |
| false | false |
| NULL | NULL |
+-------+-------+
5 rows in set (0.01 sec)

mysql> select not a and not b from t1;
+-----------------+
Expand All @@ -51,8 +64,13 @@ mysql> select not a and not b from t1;
| NULL |
+-----------------+
5 rows in set (0.00 sec)
```

## **限制**

MatrixOne 暂时还不支持 `!` 运算符。
mysql> select * from t1 where !(a=false);
+------+-------+
| a | b |
+------+-------+
| true | false |
| true | true |
+------+-------+
2 rows in set (0.00 sec)
```
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