General Functions

General functions refer to functions that all types have and are not related to specific types

nullOrDefault

A function used to describe using a default value when the value is null

Database	Dialect
MySQL	IFNULL
MSSQL	ISNULL
PGSQL	COALESCE
ORACLE	NVL

Usage

List<DocBankCard> list = easyEntityQuery.queryable(DocBankCard.class)
                    .where(bank_card -> {
                        bank_card.code().nullOrDefault("noCode").eq("123");
                    }).toList();

count | intCount

Used to get how many quantities of the current column exist. There is an overload distinct:true/false. For example, o.id().count() and o.id().count(true)

Database	Dialect
MySQL	COUNT
MSSQL	COUNT
PGSQL	COUNT
ORACLE	COUNT

Aggregate function filter supports additional operations with implicit case when

Usage

List<Draft3<Long, Long, Long>> list = easyEntityQuery.queryable(BlogEntity.class)
        .where(t_blog -> {
            t_blog.content().like("abc");
        }).select(t_blog -> Select.DRAFT.of(
                t_blog.id().count(),//count(id)
                t_blog.title().count(true),//count(distinct title)
                t_blog.title().count().filter(() -> {//count titles that are not "scary"
                    t_blog.title().ne("恐怖");
                })
        )).toList();

max | min

Used to return the maximum and minimum values of the current property

Database	Dialect	Dialect
MySQL	MAX	MIN
MSSQL	MAX	MIN
PGSQL	MAX	MIN
ORACLE	MAX	MIN

Aggregate function filter supports additional operations with implicit case when

    easyEntityQuery.queryable(BlogEntity.class)
            .where(t_blog -> {
                t_blog.content().like("abc");
            }).select(t_blog -> Select.DRAFT.of(
                    t_blog.score().max(),//max(id)
                    t_blog.score().max().filter(() -> {//get max score for titles that are not "scary"
                        t_blog.title().ne("恐怖");
                    })
            )).toList();

maxColumns | minColumns

For databases that support GREATEST and LEAST and support ignoring nulls, use this function. If not supported or if ignoring nulls is not supported, it will be supported through case when or other methods

        List<DamengMyTopic> list = entityQuery.queryable(DamengMyTopic.class)
                .where(d -> {
                    d.expression().maxColumns(d.id(), d.title(), d.title().nullOrDefault(d.id())).eq("123");
                }).toList();

This function can find out whether the maximum value of id, title, and ifnull(title) equals '123'

equalsWith

Used to compare whether two values are the same and return a true/false expression

List<Draft1<Boolean>> list = easyEntityQuery.queryable(DocBankCard.class)
                    .where(bank_card -> {
                        bank_card.code().equalsWith("myCode").eq(false);
                    })
                    .select(bank_card -> Select.DRAFT.of(
                            bank_card.id().equalsWith("123")
                    )).toList();

Database Function Related Search

IFNULL ISNULL COALESCE NVL COUNT MAX MIN