'How to display "Null" (SQLite)
On SQLite, I displayed the table "user" as shown below but "Null" is not displayed so I cannot differentiate between "Null" and Blank(Empty String):
sqlite> .header on
sqlite> .mode box
sqlite> select * from user;
┌────┬─────────────────┐
│ id │ name │
├────┼─────────────────┤
│ 1 │ Steve Jobs │
│ 2 │ │ <- Null
│ 3 │ │ <- Null
│ 4 │ Bill Gates │
│ 5 │ │ <- Blank(Empty String)
│ 6 │ Mark Zuckerberg │
└────┴─────────────────┘
Are there any ways to display "Null"?
Solution 1:[1]
This command below sets "String" values to "Null" values:
.nullvalue <String>
So, set "Null" as shown below:
.nullvalue Null
Then, "Null" are displayed for "Null" values as shown below:
sqlite> .header on
sqlite> .mode box
sqlite> select * from user;
????????????????????????
? id ? name ?
????????????????????????
? 1 ? Steve Jobs ?
? 2 ? Null ? <- Null
? 3 ? Null ? <- Null
? 4 ? Bill Gates ?
? 5 ? ? <- Blank(Empty String)
? 6 ? Mark Zuckerberg ?
????????????????????????
Next, set "This is Null." as shown below:
.nullvalue "This is Null."
Then, "This is Null" are displayed for "Null" values as shown below:
sqlite> .header on
sqlite> .mode box
sqlite> select * from user;
????????????????????????
? id ? name ?
????????????????????????
? 1 ? Steve Jobs ?
? 2 ? This is Null. ? <- Null
? 3 ? This is Null. ? <- Null
? 4 ? Bill Gates ?
? 5 ? ? <- Blank(Empty String)
? 6 ? Mark Zuckerberg ?
????????????????????????
And these commands below show the details of the command ".nullvalue":
.help .nullvalue
Or:
.help nullvalue
Then, this is how it looks like below:
sqlite> .help .nullvalue
.nullvalue STRING Use STRING in place of NULL values
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 |
