com.mybatisflex.core.util

类 MapperUtil

java.lang.Object

com.mybatisflex.core.util.MapperUtil

public class MapperUtil
extends Object

构造器概要

构造器

限定符	构造器和说明
private	MapperUtil()

方法概要

限定符和类型	方法和说明
private static boolean	canClearJoins(QueryWrapper queryWrapper)
static <T,R> Page<R>	doPaginate(BaseMapper<T> mapper, Page<R> page, QueryWrapper queryWrapper, Class<R> asType, boolean withRelations, Consumer<FieldQueryBuilder<R>>... consumers)
static Class<? extends Collection>	getCollectionWrapType(Class<?> type)
static long	getLongNumber(List<Object> objects)
static <T> T	getSelectOneResult(List<T> list) 搬运加改造 DefaultSqlSession.selectOne(String, Object)
static boolean	hasDistinct(List<QueryColumn> selectColumns)
private static boolean	hasGroupBy(List<QueryColumn> groupByColumns)
private static boolean	hasUnion(QueryWrapper countQueryWrapper)
static QueryWrapper	optimizeCountQueryWrapper(QueryWrapper queryWrapper) 优化 COUNT 查询语句。
static QueryWrapper	optimizeCountQueryWrapper(QueryWrapper queryWrapper, List<QueryColumn> customCountColumns) 优化 COUNT 查询语句。
static Map<String,Object>	preparedParams(BaseMapper<?> baseMapper, Page<?> page, QueryWrapper queryWrapper, Map<String,Object> params)
private static void	preparedQueryWrapper(Map<String,Object> params, QueryWrapper queryWrapper)
static <R> void	queryFields(BaseMapper<?> mapper, List<R> list, Consumer<FieldQueryBuilder<R>>[] consumers)
static <E> E	queryRelations(BaseMapper<?> mapper, E entity)
static <E> List<E>	queryRelations(BaseMapper<?> mapper, List<E> entities)
static QueryWrapper	rawCountQueryWrapper(QueryWrapper queryWrapper) 原生的、未经过优化的 COUNT 查询。
static QueryWrapper	rawCountQueryWrapper(QueryWrapper queryWrapper, List<QueryColumn> customCountColumns)

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

MapperUtil

private MapperUtil()

方法详细资料

rawCountQueryWrapper

public static QueryWrapper rawCountQueryWrapper(QueryWrapper queryWrapper)

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。

为什么这么说，因为是用子查询实现的，生成的 SQL 如下：

 
 SELECT COUNT(*) AS `total` FROM ( ...用户构建的 SQL 语句... ) AS `t`;
 
 

不进行 SQL 优化的时候，返回的就是这样的 COUNT 查询语句。

rawCountQueryWrapper

public static QueryWrapper rawCountQueryWrapper(QueryWrapper queryWrapper,
                                                List<QueryColumn> customCountColumns)

optimizeCountQueryWrapper

public static QueryWrapper optimizeCountQueryWrapper(QueryWrapper queryWrapper)

优化 COUNT 查询语句。

optimizeCountQueryWrapper

public static QueryWrapper optimizeCountQueryWrapper(QueryWrapper queryWrapper,
                                                     List<QueryColumn> customCountColumns)

优化 COUNT 查询语句。

hasDistinct

public static boolean hasDistinct(List<QueryColumn> selectColumns)

hasGroupBy

private static boolean hasGroupBy(List<QueryColumn> groupByColumns)

hasUnion

private static boolean hasUnion(QueryWrapper countQueryWrapper)

canClearJoins

private static boolean canClearJoins(QueryWrapper queryWrapper)

doPaginate

@SafeVarargs
public static <T,R> Page<R> doPaginate(BaseMapper<T> mapper,
                                                    Page<R> page,
                                                    QueryWrapper queryWrapper,
                                                    Class<R> asType,
                                                    boolean withRelations,
                                                    Consumer<FieldQueryBuilder<R>>... consumers)

queryFields

public static <R> void queryFields(BaseMapper<?> mapper,
                                   List<R> list,
                                   Consumer<FieldQueryBuilder<R>>[] consumers)

queryRelations

public static <E> E queryRelations(BaseMapper<?> mapper,
                                   E entity)

queryRelations

public static <E> List<E> queryRelations(BaseMapper<?> mapper,
                                         List<E> entities)

getCollectionWrapType

public static Class<? extends Collection> getCollectionWrapType(Class<?> type)

getSelectOneResult

public static <T> T getSelectOneResult(List<T> list)

搬运加改造 DefaultSqlSession.selectOne(String, Object)

getLongNumber

public static long getLongNumber(List<Object> objects)

preparedParams

public static Map<String,Object> preparedParams(BaseMapper<?> baseMapper,
                                                Page<?> page,
                                                QueryWrapper queryWrapper,
                                                Map<String,Object> params)

preparedQueryWrapper

private static void preparedQueryWrapper(Map<String,Object> params,
                                         QueryWrapper queryWrapper)