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प्रश्न
Differentiate between CHAR and VARCHAR data types in SQL with appropriate examples.
उत्तर
| S. No. | CHAR | VARCHAR |
| 1. | Used to store strings of fixed size. | Used to store strings of variable length. |
| 2. | Uses a fixed amount of storage, based on the size of the column. | Use varying amounts of storage space based on the size of the string stored. |
| 3. | Takes up 1 to 4 bytes for each character, based on the collation setting. | Takes up 1 to 4 bytes for each character based on the collation and requires one or more bytes to store the length of the data. |
| 4. | Better performance. | Slightly poorer performance because length has to be accounted for. |
Example: Consider the table student given below:
| Table: Student | ||||
| Roll | Name | Phone | Aadhar | Marks |
Every value in the Name field will take up 30 characters if the user selects char(30), regardless of whether "Ria" or "Ramakrishnan Ayyar" is the saved name.
If varchar(30) is used, "Ria" will occupy 3 units, whereas "Ramakrishnan Ayyar" will take 18 units.
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Note the following to establish connectivity between Python and MySQL:
- Username - root
- Password - tiger
- Host - localhost
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- Fee – float
Note the following to establish connectivity between Python and MySQL:
- Username - root
- Password - tiger
- Host - localhost
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