update docs

mybatis-flex-core/src/test/java/com/mybatisflex/test/AccountSqlTester.java

@@ -122,6 +122,20 @@ public class AccountSqlTester {
         System.out.println(sql);
     }
 
+    @Test
+    public void testWhereSelectSql() {
+        QueryWrapper queryWrapper = QueryWrapper.create()
+                .select()
+                .from(ACCOUNT)
+                .where(ACCOUNT.ID.ge(
+                        select(ARTICLE.ACCOUNT_ID).from(ARTICLE).where(ARTICLE.ID.ge(100))
+                ));
+
+        IDialect dialect = new CommonsDialectImpl();
+        String sql = dialect.forSelectListByQuery(queryWrapper);
+        System.out.println(sql);
+    }
+
     @Test
     public void testGroupSql() {
         QueryWrapper queryWrapper = QueryWrapper.create()

readme_zh.md

@@ -138,7 +138,8 @@ QueryWrapper query=new QueryWrapper();
 
 ```java
 QueryWrapper query=new QueryWrapper();
-        query.select(ACCOUNT.ID,ACCOUNT.USER_NAME).from(ACCOUNT)
+query.select(ACCOUNT.ID,ACCOUNT.USER_NAME)
+    .from(ACCOUNT)
 
 // SQL: 
 // SELECT id, user_name 
@@ -187,6 +188,21 @@ QueryWrapper queryWrapper=QueryWrapper.create()
 // AND user_name LIKE  ? 
 ```
 
+### where select
+```java
+QueryWrapper queryWrapper = QueryWrapper.create()
+    .select()
+    .from(ACCOUNT)
+    .where(ACCOUNT.ID.ge(
+       select(ARTICLE.ACCOUNT_ID).from(ARTICLE).where(ARTICLE.ID.ge(100))
+    ));
+
+// SQL: 
+// SELECT * FROM `tb_account` 
+// WHERE `id` >= 
+// (SELECT `account_id` FROM `tb_article` WHERE `id` >=  ? )
+```
+
 ### exists, not exists
 
 ```java
@@ -259,7 +275,8 @@ QueryWrapper queryWrapper=QueryWrapper.create()
 QueryWrapper queryWrapper=QueryWrapper.create()
     .select()
     .from(ACCOUNT)
-        .orderBy(ACCOUNT.AGE.asc(), ACCOUNT.USER_NAME.desc().nullsLast());
+    .orderBy(ACCOUNT.AGE.asc()
+        , ACCOUNT.USER_NAME.desc().nullsLast());
 
 // SQL: 
 // SELECT * FROM `tb_account`