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Solution to update field to null by JPA save() method

This article mainly introduces the solution of JPA save() method to update the field to null. The example code is introduced in detail in this article, which has a certain reference learning value for everyone’s study or work. You can refer to the following for your friends Today, there is a problem in the development. During the page presentation, it is passed to the front-end ten fields. The front-end modifies three of the...

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Summary of knowledge points related to null (ifnull, coalesce and nullif) in MySQL

The examples in this paper describe the knowledge points of null (ifnull, coalesce and nullif) in MySQL. To share with you for your reference, as follows: In mysql, a null value represents an unknown value, which is different from 0 or the empty string ” and does not equal itself. If we compare a null value with another null value or any other value, the result is null, because a value (null value) that does not know what is...

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Struct Iteration Methods Like Each, Map, And Filter Include Null Values In Lucee CFML 5.3.3.62

Earlier this week, I was working on some reflection-style code in CFML wherein I was recursively looking through structs of data. As I was doing this, it occurred to me that some of the values stored in the structs could be null; and, I wasn't sure off-hand how Lucee would handle these values during iteration. I've already demonstrated that array iteration with null values can be surprising; so, I wanted to take a moment and look at...

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Using MySQL's Null-Safe Equality Operator With CFQueryParam's Null Option In Lucee CFML 5.3.3.62

The other day, I was in the middle of writing a "typical" conditional MySQL query that had special handling for NULL values when it suddenly occurred to me that I was doing more work than I had to. I don't work with NULL values very often in SQL and ColdFusion; so, I fear that my instincts for them have never been honed properly. That said, in a moment of clarity, it occurred to me that I can use MySQL's Null-Safe equality...