“Instead of” Triggers in mysql

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再見小時候
再見小時候 2020-12-19 18:42

I have a customer.

CREATE TABLE `customer` (
    `cNic` VARCHAR(50) NOT NULL DEFAULT \'\',
    `cName` VARCHAR(100) NULL DEFAULT NULL,
    `cAddress` VARCHAR         


        
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  •  天命终不由人
    2020-12-19 19:18

    Another thing that worth notice is views in MySQL are updatable, meaning that your insert or update statement on views will automatically operate on your base table. Of course under the condition that your insert or update action won't cause any ambiguity.

    For example you have a table R(A, B) which has one tuple (1, 2). And the view V(A) is (1). If you add (10) to V, it will cause ambiguity since MySQL doesn't know it should insert (10, 1) or (10, 2) or (10, NULL) in the base table.

    More information here

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