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Beide Seiten der vorigen Revision Vorhergehende Überarbeitung Nächste Überarbeitung | Vorhergehende Überarbeitung | ||
modul:m290:learningunits:lu07:theorie:04 [2024/10/17 13:45] – vdemir | modul:m290:learningunits:lu07:theorie:04 [2024/10/17 13:49] (aktuell) – vdemir | ||
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- | ====== LU08d - SQL-DML: DELETE | + | ====== LU08d - SQL-DML: DELETE ====== |
- | ** Sources: | + | |
- | - [[https:// | + | |
- | - [[https:// | + | |
- | - [[https:// | + | |
- | .... | + | **Sources: |
+ | * [[https:// | ||
+ | |||
+ | ===== 3. DELETE Statement ===== | ||
+ | The DELETE command is used to remove records from a table. Like UPDATE, it can be run with or without a filter, making it vital to define the condition to avoid unintended data removal. | ||
===== DELETE with Filter (WHERE Clause) ===== | ===== DELETE with Filter (WHERE Clause) ===== | ||
- | ... | + | Using a WHERE clause ensures that only specific rows matching the condition will be deleted. |
- | **Syntax** | + | **Syntax:** |
- | | + | |
+ | WHERE condition; | ||
**Example** | **Example** | ||
- | ... | + | |
+ | WHERE employee_id = 1; | ||
+ | |||
+ | |||
+ | ===== DELETE without Filter ===== | ||
+ | Omitting the WHERE clause removes all data from the table, so it must be used cautiously. This operation doesn’t remove the table structure, just the rows. | ||
+ | |||
+ | **Syntax: | ||
+ | DELETE FROM table_name; | ||
+ | |||
+ | **Example: | ||
+ | DELETE FROM employees; | ||
- | ===== DELTE without Filter ===== | ||
- | .... | ||
- | **Syntax** | ||
- | | ||
- | |||
- | **Example** | ||
- | ... | ||
==== Vocabulary ==== | ==== Vocabulary ==== | ||
^English ^ Deutsch ^ | ^English ^ Deutsch ^ | ||
| ...| ... | | | ...| ... | | ||
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---- | ---- | ||
[[https:// | [[https:// | ||