代码生成模板调整，字段为String并且必填则加空串条件

ruoyi-modules/ruoyi-gen/src/main/resources/vm/xml/mapper.xml.vm

@@ -56,14 +56,14 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         <trim prefix="(" suffix=")" suffixOverrides=",">
 #foreach($column in $columns)
 #if($column.columnName != $pkColumn.columnName || !$pkColumn.increment)
-            <if test="$column.javaField != null #if($column.javaType == 'String' ) and $column.javaField != ''#end">$column.columnName,</if>
+            <if test="$column.javaField != null#if($column.javaType == 'String' && $column.required) and $column.javaField != ''#end">$column.columnName,</if>
 #end
 #end
          </trim>
         <trim prefix="values (" suffix=")" suffixOverrides=",">
 #foreach($column in $columns)
 #if($column.columnName != $pkColumn.columnName || !$pkColumn.increment)
-            <if test="$column.javaField != null #if($column.javaType == 'String' ) and $column.javaField != ''#end">#{$column.javaField},</if>
+            <if test="$column.javaField != null#if($column.javaType == 'String' && $column.required) and $column.javaField != ''#end">#{$column.javaField},</if>
 #end
 #end
          </trim>
@@ -74,7 +74,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         <trim prefix="SET" suffixOverrides=",">
 #foreach($column in $columns)
 #if($column.columnName != $pkColumn.columnName)
-            <if test="$column.javaField != null #if($column.javaType == 'String' ) and $column.javaField != ''#end">$column.columnName = #{$column.javaField},</if>
+            <if test="$column.javaField != null#if($column.javaType == 'String' && $column.required) and $column.javaField != ''#end">$column.columnName = #{$column.javaField},</if>
 #end
 #end
         </trim>