Deleting records

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The syntax of the statement for deleting records in a table is as follows:

DELETE FROM <table_name> [WHERE <search_condition>]

The above statement deletes the records that satisfy <search_condition> in the WHERE clause. If there is no WHERE clause, all the records will be deleted.

See the following examples (click here to see the contents of the original table). For Microsoft Foxpro, remember to set DELETED on before querying after deletion. Otherwise, the results of deletion cannot be seen.

Delete all records with the marks of CS lower than 50.
DELETE FROM s6a WHERE cs < 50
After execution, the table becomes:
class_num stud_id name email clc ue phy pm cs
1 92114 Chan Wai Man, Raymond s92114@sample.edu.hk 64 55 70 64 59
2 92133

Chow Chi Ling

 clchow@example.com 70 62 62 59 70
3 94302 Fung Ching Man, Mandy mandyfung@example.com 72 50 42 59 60
4 91131 Hung Wai Ming s91131@sample.edu.hk 52 48 55 39 59
5 92153 Leung King kleung@example.com 40 50 51 40 60
6 92211 Poon Kwok Fai kwokfai@testing.com.hk 59 60 70 77 75
7 91194 Sung Hing Wah, Patrick patricksung@example.com 70 72 81 69 70
8 97602 Tang Wing Chi s97602@sample.edu.hk 80 79 70 72 69
10 93211 Yeung Chun cyeung@testing.com.hk 69 80 77 60 52
11 96374 Lai Fung Chun s96374@sample.edu.hk 78 75 69 65 61
12 94412 Chan Lai Yin cly@testing.com.hk 43 59 53 61 60
13 98832 Man Fook Wing fwman@testing.com.hk 55 77 34 40 51
14 95343 Chung Kwok Fai, Fred fredchung@example.com 72 62 53 47 50
15 97233 Lee Lai May maylee@testing.com.hk 67 71 56 60 55
 
Delete all the records in the table s6a.
DELETE FROM s6a
After execution, there is no record in the table s6a.

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