diff --git a/panda-jdbc/src/main/java/org/panda/jdbc/sql/builder/MysqlBuilder.java b/panda-jdbc/src/main/java/org/panda/jdbc/sql/builder/MysqlBuilder.java
index b995a75..5d93617 100644
--- a/panda-jdbc/src/main/java/org/panda/jdbc/sql/builder/MysqlBuilder.java
+++ b/panda-jdbc/src/main/java/org/panda/jdbc/sql/builder/MysqlBuilder.java
@@ -22,6 +22,14 @@ public class MysqlBuilder extends AbstractDbBuiler {
     private static final Logger LOGGER = LoggerFactory.getLogger(MysqlBuilder.class);
 
     private static Map<String,String> dataTypeMap=new HashMap<>();
+    /**
+     * 数据库数据类型-char
+     */
+    public static final String DB_TYPE_CHAR = "char";
+    /**
+     * 数据库数据类型-int
+     */
+    public static final String DB_TYPE_INT = "int";
 
     static {
         dataTypeMap.put("class java.lang.String","varchar");
@@ -56,7 +64,6 @@ public class MysqlBuilder extends AbstractDbBuiler {
                             clazzMap.remove(column.getColumnName());
                             columnIterator.remove();
                         }
-
                     }
                     columnList.forEach(column -> {
                         sql.append("ALTER TABLE " + table.getTableName() + " DROP COLUMN " + column.getColumnName() + ";");
@@ -67,7 +74,7 @@ public class MysqlBuilder extends AbstractDbBuiler {
                         String column = BeanSqlUtil.caseToHump(f.getName());
                         String columnType = dataTypeMap.get(f.getGenericType().toString());
                         String lengthStr = "";
-                        if ("varchar".equals(columnType) || "int".equals(columnType)) {
+                        if (DB_TYPE_CHAR.equals(columnType) || DB_TYPE_CHAR.equals(columnType)) {
                             lengthStr = "(100)";
                         }
                         sql.append("ALTER TABLE " + table.getTableName() + " ADD COLUMN " + column + " " + columnType + lengthStr + ";");
@@ -104,7 +111,7 @@ public class MysqlBuilder extends AbstractDbBuiler {
         for (Map<String,String> map:mapList){
             String dataTypeStr = dataTypeMap.get(map.get("fieldType"));
             sql.append(BeanSqlUtil.caseToHump(map.get("fieldName"))+" "+dataTypeStr);
-            if ("varchar".equals(dataTypeStr)||"int".equals(dataTypeStr)){
+            if (DB_TYPE_CHAR.equals(dataTypeStr)||DB_TYPE_INT.equals(dataTypeStr)){
                 if (map.containsKey("fieldLength")) {
                     sql.append("("+map.get("fieldLength")+")");
                 }