Need help with type sql.NullInt64 for MySQL

<p>I need to input values explicitly into an Insert statement for MySQL to test some code, but I do not know what to put for variables of type sql.NullInt64. If anyone knows it would help a lot. Thanks!</p> <hr/>**评论：**<br/><br/>Kraigius: <pre><p>Does it not work when you insert the NullInt64 variable? Your column type would be BIGINT.</p> <p>You just create a new NullInt64 in go and set the Int64 field to your value and set valid to true.</p></pre>fnetma: <pre><p>Could you show me what you mean? Sorry first time using MySQL and Go. Thanks for the help!</p></pre>Kraigius: <pre><p>Sure, look at this:</p> <p><a href="https://stackoverflow.com/questions/40266633/golang-insert-null-into-sql-instead-of-empty-string" rel="nofollow">https://stackoverflow.com/questions/40266633/golang-insert-null-into-sql-instead-of-empty-string</a></p> <p>Go doesn&#39;t really have the concept of nullable unlike say, C# (<code>int? value = null;</code>)</p> <p>However, in the <code>database/sql</code> package we have a few types to help around. <a href="https://golang.org/pkg/database/sql/#NullInt64" rel="nofollow">https://golang.org/pkg/database/sql/#NullInt64</a></p> <p>They are just wrappers to help around. They contain the variable of the type that you want and a bool to tell whether or not it&#39;s a null.</p> <p>When you read from the database from a nullable BIGINT column that have &#34;42&#34; as the value it will decode into a NullInt64 in Go.</p> <p>The Int64 field will be set to 42 and Valid will be true.</p> <p>If the same column is a null value, Int64 will be 0 (default of the int64 type) with Valid to false.</p> <p>So to know if you got a null, check the Valid field first. If you want to write a null, just set the Valid field to false.</p></pre>fnetma: <pre><p>Ok I think I have it correct but I am now getting an error that says &#34; Composite literal uses unkeyed fields&#34; do you have idea what it means ?</p></pre>PaluMacil: <pre><blockquote> <p>Composite literal uses unkeyed field</p> </blockquote> <p>I hadn&#39;t seen that error myself, but <a href="https://stackoverflow.com/questions/36273920/disable-go-vet-checks-for-composite-literal-uses-unkeyed-fields" rel="nofollow">the first Google result</a> points out that if you use <code>go vet</code>, you get a lint warning for structs you declare a literal with the values and no field names. It isn&#39;t an error, so you can disable the rule in go vet, not use go vet, or probably ignore it. According to some, you should instead specify the fields when you make a struct literal. Personally, I don&#39;t care much if there are only two fields in the struct.</p></pre>