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!58 Knowing bad bug fixed.

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Merge pull request !58 from 王帅/main
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Michael Yang 2023-06-09 22:51:00 +00:00 committed by Gitee
commit 84c06feaca
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9 changed files with 261 additions and 162 deletions
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62
mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java
View File

@ -652,75 +652,26 @@ public interface BaseMapper<T> {
default <R> Page<R> paginateAs(Page<R> page, QueryWrapper queryWrapper, Class<R> asType, Consumer<FieldQueryBuilder<R>>... consumers) {
List<QueryColumn> selectColumns = CPI.getSelectColumns(queryWrapper);
List<QueryOrderBy> orderBys = CPI.getOrderBys(queryWrapper);
List<Join> joins = CPI.getJoins(queryWrapper);
boolean removedJoins = true;
// 只有 totalRow 小于 0 的时候才会去查询总量
// 这样方便用户做总数缓存，而非每次都要去查询总量
// 一般的分页场景中，只有第一页的时候有必要去查询总量，第二页以后是不需要的
if (page.getTotalRow() < 0) {
//移除 select
CPI.setSelectColumns(queryWrapper, Collections.singletonList(count().as("total")));
//移除 OrderBy
if (CollectionUtil.isNotEmpty(orderBys)) {
CPI.setOrderBys(queryWrapper, null);
}
//移除 left join
if (joins != null && !joins.isEmpty()) {
for (Join join : joins) {
if (!Join.TYPE_LEFT.equals(CPI.getJoinType(join))) {
removedJoins = false;
break;
}
}
} else {
removedJoins = false;
}
if (removedJoins) {
List<String> joinTables = new ArrayList<>();
joins.forEach(join -> {
QueryTable joinQueryTable = CPI.getJoinQueryTable(join);
if (joinQueryTable != null && StringUtil.isNotBlank(joinQueryTable.getName())) {
joinTables.add(joinQueryTable.getName());
}
});
QueryCondition where = CPI.getWhereQueryCondition(queryWrapper);
if (CPI.containsTable(where, CollectionUtil.toArrayString(joinTables))) {
removedJoins = false;
}
}
if (removedJoins) {
CPI.setJoins(queryWrapper, null);
}
queryWrapper = MapperUtil.optimizeCountQueryWrapper(queryWrapper);
long count = selectCountByQuery(queryWrapper);
page.setTotalRow(count);
}
if (page.getTotalRow() == 0 || page.getPageNumber() > page.getTotalPage()) {
if (page.isEmpty()) {
return page;
}
//重置 selectColumns
CPI.setSelectColumns(queryWrapper, selectColumns);
//重置 orderBys
if (CollectionUtil.isNotEmpty(orderBys)) {
CPI.setOrderBys(queryWrapper, orderBys);
}
CPI.setOrderBys(queryWrapper, orderBys);
//重置 join
if (removedJoins) {
CPI.setJoins(queryWrapper, joins);
}
CPI.setJoins(queryWrapper, joins);
int offset = page.getPageSize() * (page.getPageNumber() - 1);
queryWrapper.limit(offset, page.getPageSize());
@ -734,6 +685,11 @@ public interface BaseMapper<T> {
MapperUtil.queryFields(this, records, consumers);
page.setRecords(records);
}
// 将之前设置的 limit 清除掉
CPI.setLimitRows(queryWrapper, null);
CPI.setLimitOffset(queryWrapper, null);
return page;
}

36
mybatis-flex-core/src/main/java/com/mybatisflex/core/paginate/Page.java
View File

@ -1,17 +1,17 @@
/**
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
/*
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mybatisflex.core.paginate;
@ -128,6 +128,14 @@ public class Page<T> implements Serializable {
}
}
public boolean isEmpty() {
return getTotalRow() == 0 || getPageNumber() > getTotalPage();
}
public boolean hasNext() {
return getTotalPage() != 0 && getPageNumber() < getTotalPage();
}
public <R> Page<R> map(Function<? super T, ? extends R> mapper) {
Page<R> newPage = new Page<>();

33
mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryWrapper.java
View File

@ -1,17 +1,17 @@
/**
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
/*
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mybatisflex.core.query;
@ -33,6 +33,11 @@ public class QueryWrapper extends BaseQueryWrapper<QueryWrapper> {
}
public QueryWrapper select() {
return this;
}
public QueryWrapper select(String... columns) {
for (String column : columns) {
addSelectColumn(new StringQueryColumn(column));

30
mybatis-flex-core/src/main/java/com/mybatisflex/core/query/SelectQueryTable.java
View File

@ -1,17 +1,17 @@
/**
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
/*
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mybatisflex.core.query;
@ -51,7 +51,7 @@ public class SelectQueryTable extends QueryTable {
if (StringUtil.isNotBlank(alias)) {
return "(" + sql + ") AS " + dialect.wrap(alias);
} else {
return sql;
return "(" + sql + ")";
}
}
}

92
mybatis-flex-core/src/main/java/com/mybatisflex/core/row/RowMapper.java
View File

@ -1,17 +1,17 @@
/**
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
/*
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mybatisflex.core.row;
@ -21,11 +21,14 @@ import com.mybatisflex.core.paginate.Page;
import com.mybatisflex.core.provider.RowSqlProvider;
import com.mybatisflex.core.query.*;
import com.mybatisflex.core.util.CollectionUtil;
import com.mybatisflex.core.util.MapperUtil;
import com.mybatisflex.core.util.StringUtil;
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.exceptions.TooManyResultsException;
import java.util.*;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import static com.mybatisflex.core.query.QueryMethods.count;
@ -435,78 +438,37 @@ public interface RowMapper {
List<QueryOrderBy> orderBys = CPI.getOrderBys(queryWrapper);
List<Join> joins = CPI.getJoins(queryWrapper);
boolean removedJoins = true;
// 只有 totalRow 小于 0 的时候才会去查询总量
// 这样方便用户做总数缓存，而非每次都要去查询总量
// 一般的分页场景中，只有第一页的时候有必要去查询总量，第二页以后是不需要的
if (page.getTotalRow() < 0) {
//移除 seelct
CPI.setSelectColumns(queryWrapper, Collections.singletonList(count().as("total")));
//移除 OrderBy
if (CollectionUtil.isNotEmpty(orderBys)) {
CPI.setOrderBys(queryWrapper, null);
}
//移除 left join
if (joins != null && !joins.isEmpty()) {
for (Join join : joins) {
if (!Join.TYPE_LEFT.equals(CPI.getJoinType(join))) {
removedJoins = false;
break;
}
}
} else {
removedJoins = false;
}
if (removedJoins) {
List<String> joinTables = new ArrayList<>();
joins.forEach(join -> {
QueryTable joinQueryTable = CPI.getJoinQueryTable(join);
if (joinQueryTable != null && StringUtil.isNotBlank(joinQueryTable.getName())) {
joinTables.add(joinQueryTable.getName());
}
});
QueryCondition where = CPI.getWhereQueryCondition(queryWrapper);
if (CPI.containsTable(where, CollectionUtil.toArrayString(joinTables))) {
removedJoins = false;
}
}
if (removedJoins) {
CPI.setJoins(queryWrapper, null);
}
queryWrapper = MapperUtil.optimizeCountQueryWrapper(queryWrapper);
long count = selectCountByQuery(schema,tableName, queryWrapper);
page.setTotalRow(count);
}
if (page.getTotalRow() == 0 || page.getPageNumber() > page.getTotalPage()) {
if (page.isEmpty()) {
return page;
}
//重置 selectColumns
CPI.setSelectColumns(queryWrapper, selectColumns);
//重置 orderBys
if (CollectionUtil.isNotEmpty(orderBys)) {
CPI.setOrderBys(queryWrapper, orderBys);
}
CPI.setOrderBys(queryWrapper, orderBys);
//重置 join
if (removedJoins) {
CPI.setJoins(queryWrapper, joins);
}
CPI.setJoins(queryWrapper, joins);
int offset = page.getPageSize() * (page.getPageNumber() - 1);
queryWrapper.limit(offset, page.getPageSize());
List<Row> records = selectListByQuery(schema,tableName, queryWrapper);
page.setRecords(records);
// 将之前设置的 limit 清除掉
CPI.setLimitRows(queryWrapper, null);
CPI.setLimitOffset(queryWrapper, null);
return page;
}

4
mybatis-flex-core/src/main/java/com/mybatisflex/core/util/ClassUtil.java
View File

@ -105,6 +105,10 @@ public class ClassUtil {
|| clazz == double[].class;
}
public static boolean canInstance(int mod) {
return !Modifier.isAbstract(mod) || !Modifier.isInterface(mod);
}
public static <T> T newInstance(Class<T> clazz) {
try {

99
mybatis-flex-core/src/main/java/com/mybatisflex/core/util/MapperUtil.java
View File

@ -18,19 +18,112 @@ package com.mybatisflex.core.util;
import com.mybatisflex.core.BaseMapper;
import com.mybatisflex.core.field.FieldQuery;
import com.mybatisflex.core.field.FieldQueryBuilder;
import com.mybatisflex.core.query.QueryWrapper;
import com.mybatisflex.core.query.*;
import org.apache.ibatis.exceptions.TooManyResultsException;
import org.apache.ibatis.session.defaults.DefaultSqlSession;
import java.util.*;
import java.util.function.Consumer;
import static com.mybatisflex.core.query.QueryMethods.count;
public class MapperUtil {
private MapperUtil() {
}
/**
* <p>原生的、未经过优化的 COUNT 查询。抛开效率问题不谈，只关注结果的准确性，
* 这个 COUNT 查询查出来的分页总数据是 100% 正确的，不接受任何反驳。
*
* <p>为什么这么说，因为是用子查询实现的，生成的 SQL 如下：
*
* <p><pre>
* {@code
* SELECT COUNT(*) AS `total` FROM ( ...用户构建的 SQL 语句... );
* }
* </pre>
*
* <p>不进行 SQL 优化的时候，返回的就是这样的 COUNT 查询语句。
*/
public static QueryWrapper rawCountQueryWrapper(QueryWrapper queryWrapper) {
return QueryWrapper.create()
.select(count().as("total"))
.from(queryWrapper);
}
/**
* 优化 COUNT 查询语句。
*/
public static QueryWrapper optimizeCountQueryWrapper(QueryWrapper queryWrapper) {
List<QueryColumn> selectColumns = CPI.getSelectColumns(queryWrapper);
List<QueryColumn> groupByColumns = CPI.getGroupByColumns(queryWrapper);
// 如果有 distinct 语句或者 group by 语句则不优化
// 这种一旦优化了就会造成 count 语句查询出来的值不对
if (hasDistinct(selectColumns) || hasGroupBy(groupByColumns)) {
return rawCountQueryWrapper(queryWrapper);
}
// 判断能不能清除 join 语句
if (canClearJoins(queryWrapper)) {
CPI.setJoins(queryWrapper, null);
}
// 最后将最后面的 order by 移除掉
// 将 select 里面的列换成 COUNT(*) AS `total` 就好了
CPI.setOrderBys(queryWrapper, null);
CPI.setSelectColumns(queryWrapper, Collections.singletonList(count().as("total")));
return queryWrapper;
}
private static boolean hasDistinct(List<QueryColumn> selectColumns) {
if (CollectionUtil.isEmpty(selectColumns)) {
return false;
}
for (QueryColumn selectColumn : selectColumns) {
if (selectColumn instanceof DistinctQueryColumn) {
return true;
}
}
return false;
}
private static boolean hasGroupBy(List<QueryColumn> groupByColumns) {
return CollectionUtil.isNotEmpty(groupByColumns);
}
private static boolean canClearJoins(QueryWrapper queryWrapper) {
List<Join> joins = CPI.getJoins(queryWrapper);
if (CollectionUtil.isEmpty(joins)) {
return false;
}
// 只有全是 left join 语句才会清除 join
// 因为如果是 inner join 或 right join 往往都会放大记录数
for (Join join : joins) {
if (!Join.TYPE_LEFT.equals(CPI.getJoinType(join))) {
return false;
}
}
// 获取 join 语句中使用到的表名
List<String> joinTables = new ArrayList<>();
// Map<String, String> joinTables = new HashMap<>();
joins.forEach(join -> {
QueryTable joinQueryTable = CPI.getJoinQueryTable(join);
if (joinQueryTable != null && StringUtil.isNotBlank(joinQueryTable.getName())) {
joinTables.add(joinQueryTable.getName());
}
});
// 获取 where 语句中的条件
QueryCondition where = CPI.getWhereQueryCondition(queryWrapper);
// 最后判断一下 where 中是否用到了 join 的表
return !CPI.containsTable(where, CollectionUtil.toArrayString(joinTables));
}
@SuppressWarnings({"rawtypes", "unchecked"})
public static <R> void queryFields(BaseMapper<?> mapper, List<R> list, Consumer<FieldQueryBuilder<R>>[] consumers) {
if (CollectionUtil.isEmpty(list) || ArrayUtil.isEmpty(consumers) || consumers[0] == null) {
return;
@ -69,6 +162,10 @@ public class MapperUtil {
private static Class<?> getWrapType(Class<?> type) {
if (ClassUtil.canInstance(type.getModifiers())) {
return type;
}
if (List.class.isAssignableFrom(type)) {
return ArrayList.class;
}

48
mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/common/MapperUtilTest.java Normal file
View File

@ -0,0 +1,48 @@
/*
* Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
* <p>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mybatisflex.test.common;
import com.mybatisflex.core.query.QueryWrapper;
import com.mybatisflex.core.util.MapperUtil;
import org.junit.jupiter.api.Test;
import static com.mybatisflex.test.model.table.RoleTableDef.ROLE;
import static com.mybatisflex.test.model.table.UserRoleTableDef.USER_ROLE;
import static com.mybatisflex.test.model.table.UserTableDef.USER;
/**
* @author 王帅
* @since 2023-06-09
*/
class MapperUtilTest {
@Test
void testOptimizeCountQueryWrapper() {
QueryWrapper queryWrapper = QueryWrapper.create()
.select(USER.USER_ID, USER.USER_NAME, ROLE.ALL_COLUMNS)
.from(USER.as("u"))
.leftJoin(USER_ROLE).as("ur").on(USER_ROLE.USER_ID.eq(USER.USER_ID))
.leftJoin(ROLE).as("r").on(USER_ROLE.ROLE_ID.eq(ROLE.ROLE_ID))
.where(USER.USER_ID.eq(3))
.and(USER_ROLE.ROLE_ID.eq(6))
.groupBy(ROLE.ROLE_ID);
System.out.println(queryWrapper.toSQL());
System.out.println(MapperUtil.rawCountQueryWrapper(queryWrapper).toSQL());
System.out.println(MapperUtil.optimizeCountQueryWrapper(queryWrapper).toSQL());
}
}

19
mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/mapper/UserMapperTest.java
View File

@ -16,6 +16,7 @@
package com.mybatisflex.test.mapper;
import com.mybatisflex.core.paginate.Page;
import com.mybatisflex.core.query.QueryWrapper;
import com.mybatisflex.test.model.UserInfo;
import com.mybatisflex.test.model.UserVO;
@ -39,6 +40,7 @@ import static com.mybatisflex.test.model.table.UserTableDef.USER;
* @since 2023-06-07
*/
@SpringBootTest
@SuppressWarnings("all")
class UserMapperTest {
@Autowired
@ -114,4 +116,21 @@ class UserMapperTest {
userInfos.forEach(System.err::println);
}
@Test
void testPage() {
QueryWrapper queryWrapper = QueryWrapper.create()
.select(USER.USER_ID, USER.USER_NAME, ROLE.ALL_COLUMNS)
.from(USER.as("u"))
.leftJoin(USER_ROLE).as("ur").on(USER_ROLE.USER_ID.eq(USER.USER_ID))
.leftJoin(ROLE).as("r").on(USER_ROLE.ROLE_ID.eq(ROLE.ROLE_ID));
System.err.println(queryWrapper.toSQL());
Page<UserVO> page;
int pageNumber = 0;
do {
page = Page.of(++pageNumber, 1);
page = userMapper.paginateAs(page, queryWrapper, UserVO.class);
System.err.println(page);
} while (page.hasNext());
}
}