feat: 生成编号和删除限制等

agt-module-license/agt-module-license-server/src/main/resources/mapper/project/ProjectMapper.xml

@@ -3,7 +3,14 @@
 <mapper namespace="org.agt.module.license.dal.mysql.project.ProjectMapper">
 
     <select id="selectMaxCode" resultType="Integer">
-        SELECT max(`code` + 0) from crm_project;
+        SELECT
+        	MIN( t1.num + 1 ) AS next_num
+        FROM
+        	( SELECT CAST( `code` AS UNSIGNED ) AS num FROM crm_project ) t1
+        	LEFT JOIN ( SELECT CAST( `code` AS UNSIGNED ) AS num FROM crm_project ) t2 ON t2.num = t1.num + 1
+        WHERE
+        	t2.num IS NULL
+        	AND t1.num >= 2000
     </select>
 
     <select id="selectOldMaxCode" resultType="Integer">