| Beide Seiten der vorigen Revision Vorhergehende Überarbeitung Nächste Überarbeitung | Vorhergehende Überarbeitung |
| modul:m290:learningunits:lu03:loesungen:l01 [2024/08/14 13:45] – vdemir | modul:m290:learningunits:lu03:loesungen:l01 [2024/10/17 12:32] (aktuell) – vdemir |
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| ====== LU03.L01 - Choose data-types ====== | ====== LU04.S01 - Choose data-types ====== |
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| ===== Task a) Choose datatypes ==== | |
| Which datatype would you use to store the following information? Give reason for your decision. | Which datatype would you use to store the following information? Give reason for your decision. |
| |
| * product-title like trousers up to 50 characters: | 1. Product-title like trousers up to 50 characters: |
| * <color #ed1c24>VARCHAR(50)</color> | *<color #ed1c24>VARCHAR(50)</color> |
| * <color #ed1c24>Titles can be at the most 50 characters. A fix length makes not sense in that case. | *<color #ed1c24>Titles can be at the most 50 characters. A fix length like a simple CHAR(50) makes no sense in that case. </color> |
| * product-description up to 255 characters: | |
| * <color #ed1c24>VARCHAR(255)</color> | |
| * <color #ed1c24>The description can be 255 characters, but can also be shorter. A fix length does not make sense in that case. </color> | |
| * stock amount: | |
| * <color #ed1c24>INT or INTEGER</color> | |
| * <color #ed1c24>Floating point type is not suitable as pieces are always counted in whole numbers. </color> | |
| * price of each piece: | |
| * <color #ed1c24>FLOAT(5,2) or DECIMAL(U5,2)</color> | |
| * <color #ed1c24>Prices have floating point</color> | |
| * <color #ed1c24>The length of (5,2) should be sufficient enough as trousers are usually within a price ranger of 0.99 to 999.99. </color> | |
| * order date: | |
| * <color #ed1c24>DATETIME or TIMESTAMP | |
| * <color #ed1c24>The type depends on whether we want to safe only the date, but also the time. | |
| * <color #ed1c24>Important is, that the in this case the storage of the current time. | |
| * <color #ed1c24>date of delivery: | |
| * whether organical or not: | |
| * <color #ed1c24>BOOLEAN</color> | |
| * <color #ed1c24>As there a only two posibilites to store a boolan data-type is the correct data-type. | |
| * usage category with only one character: | |
| * <color #ed1c24>As long as there is only one character to be stored the CHAR-type will work. </color> | |
| * <color #ed1c24>Technically the CHAR-types allows all letters, digits (as letters) and special characters.</color> | |
| |
| ===== Solution ===== | 2. Product-description up to 255 characters: |
| [[modul:m290:learningunits:lu03:loesungen:l01|Lösung]] | *<color #ed1c24>VARCHAR(255)</color> |
| | *<color #ed1c24>The description can be 255 characters, but can also be shorter. A fix length does not make sense in that case. </color> |
| |
| | 3. Stock amount: |
| | *<color #ed1c24>INT or INTEGER</color> |
| | *<color #ed1c24>Floating point type is not suitable as pieces are always counted in whole numbers. </color> |
| | |
| | 4. Price of each piece: |
| | *<color #ed1c24>FLOAT(6,2) or DECIMAL(6,2)</color> |
| | *<color #ed1c24>Prices have floating point</color> |
| | * <color #ed1c24>The length of (6,2) should be sufficient enough as trousers are usually within a price ranger of 0.99 to 9999.99. </color> |
| | |
| | 5. Order date: |
| | *<color #ed1c24>DATE or DATETIME</color> |
| | *<color #ed1c24>The type depends on whether we want to safe only the date, but also the time. </color> |
| | *<color #ed1c24>Usually in such cases to store only the order-date is enough.</color> |
| | |
| | 6. Date of delivery: |
| | *<color #ed1c24>DATETIME or TIMESTAMP</color> |
| | *<color #ed1c24>Regarding delivery quality the criteria punctuality might be one key element. Therefore the storage of the delivery-time is compulsory.</color> |
| | |
| | 7. organic or not: |
| | *<color #ed1c24>BOOLEAN</color> |
| | *<color #ed1c24>As there a only two possibilites to store a boolean data-type is the correct data-type. </color> |
| | |
| | 8. Usage category with only one character: |
| | * <color #ed1c24>CHAR</color> |
| | * <color #ed1c24>As long as there is only one character to be stored the CHAR-type will work. </color> |
| | * <color #ed1c24>Technically the CHAR-types allows all letters, digits (as letters) and special characters.</color> |
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| ===== Vocabulary ===== | ===== Vocabulary ===== |
| ^ English ^ German ^ | ^ English ^ German ^ |
| | respectively | beziehungsweise| | | to give reason for | begründen | |
| | | at the most | höchstens | |
| | | stock amount | Lagermenge | |
| | | to float | fliessen | |
| | | sufficient | ausreichend | |
| | | regarding | bezüglich | |
| | | might be | möglicherweise | |
| | | technically | im Prinzip, eigentlich | |
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| ---- | ---- |
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| [[https://creativecommons.org/licenses/by-nc-sa/4.0/|{{https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png}}]] Volkan Demir | [[https://creativecommons.org/licenses/by-nc-sa/4.0/|{{https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png}}]] Volkan Demir |