Mybatis-Plus框架：条件构造器

AbstractWrapper

说明:

QueryWrapper(LambdaQueryWrapper)和 UpdateWrapper(LambdaUpdateWrapper) 的父类

用于生成sql的 where 条件, entity 属性也用于生成 sql 的 where 条件

注意: entity生成的 where 条件与 使用各个 api 生成的 where 条件没有任何关联行为

说明:

以下出现的第一个入参boolean condition表示该条件是否加入最后生成的sql中，例如：query.like(StringUtils.isNotBlank(name), Entity::getName, name) .eq(age!=null && age >= 0, Entity::getAge, age)

以下代码块内的多个方法均为从上往下补全个别boolean类型的入参,默认为true

以下出现的泛型Param均为Wrapper的子类实例(均具有AbstractWrapper的所有方法)

以下方法在入参中出现的R为泛型,在普通wrapper中是String,在LambdaWrapper中是函数(例:Entity::getId,Entity为实体类,getId为字段id的getter Method)

以下方法入参中的R column均表示数据库字段,当R具体类型为String时则为数据库字段名(字段名是数据库关键字的自己用转义符包裹!)!而不是实体类数据字段名!!!,另当R具体类型为SFunction时项目runtime不支持eclipse自家的编译器!!!

以下举例均为使用普通wrapper,入参为Map和List的均以json形式表现!

使用中如果入参的Map或者List为空,则不会加入最后生成的sql中!!!

#eq

eq(R column, Object val)

eq(boolean condition, R column, Object val)

等于=

例: eq("name", "老王")--->name = '老王'

#ne

ne(R column, Object val)

ne(boolean condition, R column, Object val)

不等于

例: ne("name", "老王")--->name '老王'

#gt

gt(R column, Object val)

gt(boolean condition, R column, Object val)

大于>

例: gt("age", 18)--->age > 18

#ge

ge(R column, Object val)

ge(boolean condition, R column, Object val)

大于等于>=

例: ge("age", 18)--->age >= 18

#lt

lt(R column, Object val)

lt(boolean condition, R column, Object val)

小于

例: lt("age", 18)--->age < 18

#le

le(R column, Object val)

le(boolean condition, R column, Object val)

小于等于

例: le("age", 18)--->age

#between

between(R column, Object val1, Object val2)

between(boolean condition, R column, Object val1, Object val2)

BETWEEN值1 AND 值2

例: between("age", 18, 30)--->age between 18 and 30

#notBetween

notBetween(R column, Object val1, Object val2)

notBetween(boolean condition, R column, Object val1, Object val2)

NOT BETWEEN值1 AND 值2

例: notBetween("age", 18, 30)--->age not between 18 and 30

#like

like(R column, Object val)

like(boolean condition, R column, Object val)

LIKE '%值%'

例: like("name", "王")--->name like '%王%'

#notLike

notLike(R column, Object val)

notLike(boolean condition, R column, Object val)

NOT LIKE '%值%'

例: notLike("name", "王")--->name not like '%王%'

#likeLeft

likeLeft(R column, Object val)

likeLeft(boolean condition, R column, Object val)

LIKE '%值'

例: likeLeft("name", "王")--->name like '%王'

#likeRight

likeRight(R column, Object val)

likeRight(boolean condition, R column, Object val)

LIKE '值%'

例: likeRight("name", "王")--->name like '王%'

#notLikeLeft

notLikeLeft(R column, Object val)

notLikeLeft(boolean condition, R column, Object val)

NOT LIKE '%值'

例: notLikeLeft("name", "王")--->name not like '%王'

#notLikeRight

notLikeRight(R column, Object val)

notLikeRight(boolean condition, R column, Object val)

NOT LIKE '值%'

例: notLikeRight("name", "王")--->name not like '王%'

#isNull

isNull(R column)

isNull(boolean condition, R column)

字段IS NULL

例: isNull("name")--->name is null

#isNotNull

isNotNull(R column)

isNotNull(boolean condition, R column)

字段IS NOT NULL

例: isNotNull("name")--->name is not null

#in

in(R column, Collection value)

in(boolean condition, R column, Collection value)

字段IN (value.get(0), value.get(1), ...)

例: in("age",{1,2,3})--->age in (1,2,3)

in(R column, Object... values)

in(boolean condition, R column, Object... values)

字段IN (v0, v1, ...)

例: in("age", 1, 2, 3)--->age in (1,2,3)

#notIn

notIn(R column, Collection value)

notIn(boolean condition, R column, Collection value)

字段NOT IN (value.get(0), value.get(1), ...)

例: notIn("age",{1,2,3})--->age not in (1,2,3)

notIn(R column, Object... values)

notIn(boolean condition, R column, Object... values)

字段NOT IN (v0, v1, ...)

例: notIn("age", 1, 2, 3)--->age not in (1,2,3)

#inSql

inSql(R column, String inValue)

inSql(boolean condition, R column, String inValue)

字段IN ( sql语句 )

例: inSql("age", "1,2,3,4,5,6")--->age in (1,2,3,4,5,6)

例: inSql("id", "select id from table where id < 3")--->id in (select id from table where id < 3)

#notInSql

notInSql(R column, String inValue)

notInSql(boolean condition, R column, String inValue)

字段NOT IN ( sql语句 )

例: notInSql("age", "1,2,3,4,5,6")--->age not in (1,2,3,4,5,6)

例: notInSql("id", "select id from table where id < 3")--->id not in (select id from table where id < 3)

#groupBy

groupBy(R... columns)

groupBy(boolean condition, R... columns)

分组：GROUP BY字段, ...

例: groupBy("id", "name")--->group by id,name

#orderByAsc

orderByAsc(R... columns)

orderByAsc(boolean condition, R... columns)

排序：ORDER BY字段, ... ASC

例: orderByAsc("id", "name")--->order by id ASC,name ASC

#orderByDesc

orderByDesc(R... columns)

orderByDesc(boolean condition, R... columns)

排序：ORDER BY字段, ... DESC

例: orderByDesc("id", "name")--->order by id DESC,name DESC

#orderBy

orderBy(boolean condition, boolean isAsc, R... columns)

排序：ORDER BY字段, ...

例: orderBy(true, true, "id", "name")--->order by id ASC,name ASC

#having

having(String sqlHaving, Object... params)

having(boolean condition, String sqlHaving, Object... params)

HAVING ( sql语句 )

例: having("sum(age) > 10")--->having sum(age) > 10

例: having("sum(age) > {0}", 11)--->having sum(age) > 11

#or

or()

or(boolean condition)

拼接OR

注意事项:

主动调用or表示紧接着下一个方法不是用and连接!(不调用or则默认为使用and连接)

例: eq("id",1).or().eq("name","老王")--->id = 1 or name = '老王'

or(Consumer consumer)

or(boolean condition, Consumer consumer)

OR嵌套

例: or(i -> i.eq("name", "李白").ne("status", "活着"))--->or (name = '李白' and status '活着')

and(Consumer consumer)

and(boolean condition, Consumer consumer)

AND嵌套

例: and(i -> i.eq("name", "李白").ne("status", "活着"))--->and (name = '李白' and status '活着')

#exists

exists(String existsSql)

exists(boolean condition, String existsSql)

拼接EXISTS ( sql语句 )

例: exists("select id from table where age = 1")--->exists (select id from table where age = 1)

#notExists

notExists(String notExistsSql)

notExists(boolean condition, String notExistsSql)

拼接NOT EXISTS ( sql语句 )

例: notExists("select id from table where age = 1")--->not exists (select id from table where age = 1)