It will only work in an Oracle Database 11 g database because the context of using a sequence_name.CURRVAL in a comparison isn’t supported in prior releases. This trigger disallows numeric literals, logs any attempts to use them, and stops processing when an INSERT statement tries to use anything other than the.
It assumes that bulk operations will be performed as batch processing where you can disable this trigger. So, here’s my take on a trigger that prevents collision with values above the next sequence value. Beyond it’s impracticality to manage, that type of restriction does limit the benefit of bulk operations. You could also implement a policy that no bulk operations provide generated column values that link to a sequence. You could treat these bulk operations as off-line transactions (batch processing) and it would work nicely. After the bulk operation you would drop and recreate the sequence with a new value equal to the maximum value in the column, and unlock the table. Yes, you could lock the table before you perform the bulk operation. The next call to the trigger would raise another ORA-00001 unique constraint error. Then, you perform the bulk INSERT statement. Assuming you’re inserting 500 rows at a go, you query the maximum value of the onesy_id column and then create an array of 500 numbers. ORA-00001: unique constraint (STUDENT.PK_ONE) violatedĪnother possible error can occur when you use a bulk insert operation. INSERT INTO onesy (onesy_text) VALUES ('Eight') INSERT INTO onesy (onesy_text ) VALUES ( 'Eight' ) *
The following demonstrates the final parameter validating function. You must modify the if-block by checking whether the call parameter is some data type other than a number before assigning a default value. The return of a string value is clearly not the desired behavior. The modified function returns (a) the call parameter value, (b) 21 when the call parameter points to (references) an empty cell, (c) 22 when you exclude the variable from the call parameter list, or (d) any string value found in the call parameter. ' Return the unfiltered call parameter unless empty then return 21. ' Explicit assignments required when a cell reference points to an empty cell. Function OptionalOverride(Optional opt As Variant = 22)
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