update docs

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

@@ -2,6 +2,8 @@ package com.mybatisflex.test;
 
 import com.mybatisflex.core.dialect.CommonsDialectImpl;
 import com.mybatisflex.core.dialect.IDialect;
+import com.mybatisflex.core.dialect.KeywordWrap;
+import com.mybatisflex.core.dialect.LimitOffsetProcesser;
 import com.mybatisflex.core.querywrapper.CPI;
 import com.mybatisflex.core.querywrapper.QueryWrapper;
 import com.mybatisflex.core.table.TableInfo;
@@ -195,6 +197,47 @@ public class AccountSqlTester {
     }
 
 
+    @Test
+    public void testLimitOffset() {
+
+        QueryWrapper queryWrapper = QueryWrapper.create()
+                .select()
+                .from(ACCOUNT)
+                .orderBy(ACCOUNT.ID.desc())
+                .limit(10)
+                .offset(20);
+
+        IDialect dialect1 = new CommonsDialectImpl();
+        String sql1 = dialect1.buildSelectSql(queryWrapper);
+        System.out.println(sql1);
+
+        IDialect dialect2 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.ORACLE);
+        String sql2 = dialect2.buildSelectSql(queryWrapper);
+        System.out.println(sql2);
+
+        IDialect dialect3 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.DB2);
+        String sql3 = dialect3.buildSelectSql(queryWrapper);
+        System.out.println(sql3);
+
+        IDialect dialect4 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.POSTGRESQL);
+        String sql4 = dialect4.buildSelectSql(queryWrapper);
+        System.out.println(sql4);
+
+        IDialect dialect5 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.INFORMIX);
+        String sql5 = dialect5.buildSelectSql(queryWrapper);
+        System.out.println(sql5);
+
+        IDialect dialect6 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.SYBASE);
+        String sql6 = dialect6.buildSelectSql(queryWrapper);
+        System.out.println(sql6);
+
+
+        IDialect dialect7 = new CommonsDialectImpl(KeywordWrap.DOUBLE_QUOTATION, LimitOffsetProcesser.FIREBIRD);
+        String sql7 = dialect7.buildSelectSql(queryWrapper);
+        System.out.println(sql7);
+    }
+
+
     @Test
     public void testrSelectLimitSql() {
         QueryWrapper queryWrapper = QueryWrapper.create()

readme.md

@@ -270,7 +270,43 @@ QueryWrapper queryWrapper = QueryWrapper.create()
 // LEFT JOIN tb_article 
 // ON tb_account.id = tb_article.account_id 
 // WHERE tb_account.age >=  ?
+```
 
+
+### limit... offset
+
+```java
+QueryWrapper queryWrapper = QueryWrapper.create()
+    .select()
+    .from(ACCOUNT)
+    .orderBy(ACCOUNT.ID.desc())
+    .limit(10)
+    .offset(20);
+
+// MySql: 
+// SELECT * FROM `tb_account` ORDER BY `id` DESC LIMIT 20, 10
+
+// postgreSQL: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC LIMIT 20 OFFSET 10
+
+// informix: 
+// SELECT SKIP 20 FIRST 10 * FROM "tb_account" ORDER BY "id" DESC
+
+// oracle: 
+// SELECT * FROM (SELECT TEMP_DATAS.*, 
+//  ROWNUM RN FROM (
+//          SELECT * FROM "tb_account" ORDER BY "id" DESC) 
+//      TEMP_DATAS WHERE  ROWNUM <=30) 
+//  WHERE RN >20
+
+// db2: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC OFFSET 20  ROWS FETCH NEXT 10 ROWS ONLY
+
+// sybase: 
+// SELECT TOP 10 START AT 30 * FROM "tb_account" ORDER BY "id" DESC
+
+// firebird: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC ROWS 20 TO 30
 ```
 
 ### Questions？

readme_zh.md

@@ -309,6 +309,43 @@ QueryWrapper queryWrapper=QueryWrapper.create()
 // WHERE tb_account.age >=  ?
 ```
 
+
+### limit... offset
+
+```java
+QueryWrapper queryWrapper = QueryWrapper.create()
+    .select()
+    .from(ACCOUNT)
+    .orderBy(ACCOUNT.ID.desc())
+    .limit(10)
+    .offset(20);
+
+// MySql: 
+// SELECT * FROM `tb_account` ORDER BY `id` DESC LIMIT 20, 10
+
+// postgreSQL: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC LIMIT 20 OFFSET 10
+
+// informix: 
+// SELECT SKIP 20 FIRST 10 * FROM "tb_account" ORDER BY "id" DESC
+
+// oracle: 
+// SELECT * FROM (SELECT TEMP_DATAS.*, 
+//  ROWNUM RN FROM (
+//          SELECT * FROM "tb_account" ORDER BY "id" DESC) 
+//      TEMP_DATAS WHERE  ROWNUM <=30) 
+//  WHERE RN >20
+
+// db2: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC OFFSET 20  ROWS FETCH NEXT 10 ROWS ONLY
+
+// sybase: 
+// SELECT TOP 10 START AT 30 * FROM "tb_account" ORDER BY "id" DESC
+
+// firebird: 
+// SELECT * FROM "tb_account" ORDER BY "id" DESC ROWS 20 TO 30
+```
+
 ### 存在疑问？
 
 **疑问 1：QueryWrapper 是否可以在分布式项目中通过 RPC 传输？**