::: tip 说明:
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)boolean
类型的入参,默认为true
Param
均为Wrapper
的子类实例(均具有AbstractWrapper
的所有方法)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getMethod)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!!!Map
和List
的均以json
形式表现!Map
或者List
为空,则不会加入最后生成的sql中!!!::: danger 警告:
不支持以及不赞成在 RPC 调用中把 Wrapper 进行传输
::: tip 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
:::
allEq(Map<R, V> params)
allEq(Map<R, V> params, boolean null2IsNull)
allEq(boolean condition, Map<R, V> params, boolean null2IsNull)
params
: key
为数据库字段名,value
为字段值null2IsNull
: 为true
则在map
的value
为null
时调用 isNull 方法,为false
时则忽略value
为null
的allEq({id:1,name:"老王",age:null})
--->id = 1 and name = '老王' and age is null
allEq({id:1,name:"老王",age:null}, false)
--->id = 1 and name = '老王'
allEq(BiPredicate<R, V> filter, Map<R, V> params)
allEq(BiPredicate<R, V> filter, Map<R, V> params, boolean null2IsNull)
allEq(boolean condition, BiPredicate<R, V> filter, Map<R, V> params, boolean null2IsNull)
::: tip 个别参数说明:filter
: 过滤函数,是否允许字段传入比对条件中params
与 null2IsNull
: 同上
:::
allEq((k,v) -> k.indexOf("a") >= 0, {id:1,name:"老王",age:null})
--->name = '老王' and age is null
allEq((k,v) -> k.indexOf("a") >= 0, {id:1,name:"老王",age:null}, false)
--->name = '老王'
eq(R column, Object val)
eq(boolean condition, R column, Object val)
eq("name", "老王")
--->name = '老王'
ne(R column, Object val)
ne(boolean condition, R column, Object val)
ne("name", "老王")
--->name <> '老王'
gt(R column, Object val)
gt(boolean condition, R column, Object val)
gt("age", 18)
--->age > 18
ge(R column, Object val)
ge(boolean condition, R column, Object val)
ge("age", 18)
--->age >= 18
lt(R column, Object val)
lt(boolean condition, R column, Object val)
lt("age", 18)
--->age < 18
le(R column, Object val)
le(boolean condition, R column, Object val)
le("age", 18)
--->age <= 18
between(R column, Object val1, Object val2)
between(boolean condition, R column, Object val1, Object val2)
between("age", 18, 30)
--->age between 18 and 30
notBetween(R column, Object val1, Object val2)
notBetween(boolean condition, R column, Object val1, Object val2)
notBetween("age", 18, 30)
--->age not between 18 and 30
like(R column, Object val)
like(boolean condition, R column, Object val)
like("name", "王")
--->name like '%王%'
notLike(R column, Object val)
notLike(boolean condition, R column, Object val)
notLike("name", "王")
--->name not like '%王%'
likeLeft(R column, Object val)
likeLeft(boolean condition, R column, Object val)
likeLeft("name", "王")
--->name like '%王'
likeRight(R column, Object val)
likeRight(boolean condition, R column, Object val)
likeRight("name", "王")
--->name like '王%'
isNull(R column)
isNull(boolean condition, R column)
isNull("name")
--->name is null
isNotNull(R column)
isNotNull(boolean condition, R column)
isNotNull("name")
--->name is not null
in(R column, Collection<?> value)
in(boolean condition, R column, Collection<?> value)
in("age",{1,2,3})
--->age in (1,2,3)
in(R column, Object... values)
in(boolean condition, R column, Object... values)
in("age", 1, 2, 3)
--->age in (1,2,3)
notIn(R column, Collection<?> value)
notIn(boolean condition, R column, Collection<?> value)
notIn("age",{1,2,3})
--->age not in (1,2,3)
notIn(R column, Object... values)
notIn(boolean condition, R column, Object... values)
notIn("age", 1, 2, 3)
--->age not in (1,2,3)
inSql(R column, String inValue)
inSql(boolean condition, R column, String inValue)
inSql("age", "1,2,3,4,5,6")
--->age in (1,2,3,4,5,6)
inSql("id", "select id from table where id < 3")
--->id in (select id from table where id < 3)
notInSql(R column, String inValue)
notInSql(boolean condition, R column, String inValue)
notInSql("age", "1,2,3,4,5,6")
--->age not in (1,2,3,4,5,6)
notInSql("id", "select id from table where id < 3")
--->id not in (select id from table where id < 3)
groupBy(R... columns)
groupBy(boolean condition, R... columns)
groupBy("id", "name")
--->group by id,name
orderByAsc(R... columns)
orderByAsc(boolean condition, R... columns)
orderByAsc("id", "name")
--->order by id ASC,name ASC
orderByDesc(R... columns)
orderByDesc(boolean condition, R... columns)
orderByDesc("id", "name")
--->order by id DESC,name DESC
orderBy(boolean condition, boolean isAsc, R... columns)
orderBy(true, true, "id", "name")
--->order by id ASC,name ASC
having(String sqlHaving, Object... params)
having(boolean condition, String sqlHaving, Object... params)
having("sum(age) > 10")
--->having sum(age) > 10
having("sum(age) > {0}", 11)
--->having sum(age) > 11
func(Consumer<Children> consumer)
func(boolean condition, Consumer<Children> consumer)
func(i -> if(true) {i.eq("id", 1)} else {i.ne("id", 1)})
or()
or(boolean condition)
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)eq("id",1).or().eq("name","老王")
--->id = 1 or name = '老王'
or(Consumer<Param> consumer)
or(boolean condition, Consumer<Param> consumer)
or(i -> i.eq("name", "李白").ne("status", "活着"))
--->or (name = '李白' and status <> '活着')
and(Consumer<Param> consumer)
and(boolean condition, Consumer<Param> consumer)
and(i -> i.eq("name", "李白").ne("status", "活着"))
--->and (name = '李白' and status <> '活着')
nested(Consumer<Param> consumer)
nested(boolean condition, Consumer<Param> consumer)
nested(i -> i.eq("name", "李白").ne("status", "活着"))
--->(name = '李白' and status <> '活着')
apply(String applySql, Object... params)
apply(boolean condition, String applySql, Object... params)
params
对应前面applySql
内部的{index}
部分.这样是不会有sql注入风险的,反之会有!apply("id = 1")
--->id = 1
apply("date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'")
--->date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'")
apply("date_format(dateColumn,'%Y-%m-%d') = {0}", "2008-08-08")
--->date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'")
last(String lastSql)
last(boolean condition, String lastSql)
last("limit 1")
exists(String existsSql)
exists(boolean condition, String existsSql)
exists("select id from table where age = 1")
--->exists (select id from table where age = 1)
notExists(String notExistsSql)
notExists(boolean condition, String notExistsSql)
notExists("select id from table where age = 1")
--->not exists (select id from table where age = 1)
::: tip 说明:
继承自 AbstractWrapper ,自身的内部属性 entity 也用于生成 where 条件
及 LambdaQueryWrapper, 可以通过 new QueryWrapper().lambda() 方法获取
:::
select(String... sqlSelect)
select(Predicate<TableFieldInfo> predicate)
select(Class<T> entityClass, Predicate<TableFieldInfo> predicate)
wrapper
内的entity
属性有值!select("id", "name", "age")
select(i -> i.getProperty().startsWith("test"))
::: tip 说明:
继承自 AbstractWrapper
,自身的内部属性 entity
也用于生成 where 条件
及 LambdaUpdateWrapper
, 可以通过 new UpdateWrapper().lambda()
方法获取!
:::
set(String column, Object val)
set(boolean condition, String column, Object val)
set("name", "老李头")
set("name", "")
--->数据库字段值变为空字符串set("name", null)
--->数据库字段值变为null
setSql(String sql)
setSql("name = '老李头'")
LambdaWrapper
QueryWrapper
中是获取LambdaQueryWrapper
UpdateWrapper
中是获取LambdaUpdateWrapper
::: tip 注意事项:
需要mybatis-plus
版本 >= 3.0.7
param 参数名要么叫ew
,要么加上注解@Param(Constants.WRAPPER)
使用${ew.customSqlSegment}
不支持 Wrapper
内的entity生成where语句
:::
由于kotlin
相比于java
多了数据对象(data class
),在未说明情况下可能会混用。建议按照以下形式定义持久化对象
@TableName("sys_user")
class User {
@TableId(type = IdType.AUTO)
var id: Int? = null
@TableField("username")
var name: String? = null
var roleId: Int? = null
}
注意:这里的TableId
及TableField
并非必要,只是为了展示Mybatis-Plus
中的annotation
使用
这里所有成员都需要定义为可空类型(?
),并赋予null
的初始值,方便我们在以下场景中使用(类似java中的updateSelective
)
val wrapper = KtUpdateWrapper(User::class.java).eq(User::id, 2)
val newRecord = User()
newRecord.name = "newName"
userMapper!!.update(newRecord, wrapper)
不建议使用data class
及全参数构造方法,这样我们会写很多不必要的null
来构造一个空对象
@Select("select * from mysql_data ${ew.customSqlSegment}")
List<MysqlData> getAll(@Param(Constants.WRAPPER) Wrapper wrapper);
List<MysqlData> getAll(Wrapper ew);
<select id="getAll" resultType="MysqlData">
SELECT * FROM mysql_data ${ew.customSqlSegment}
</select>
kotlin 可以使用
QueryWrapper
和UpdateWrapper
但无法使用LambdaQueryWrapper
和LambdaUpdateWrapper
如果想使用 lambda 方式的 wrapper 请使用KtQueryWrapper
和KtUpdateWrapper
请参考实例
val queryWrapper = KtQueryWrapper(User()).eq(User::name, "sss").eq(User::roleId, "sss2")
userMapper!!.selectList(queryWrapper)
val updateConditionWrapper = KtUpdateWrapper(User()).eq(User::name, "sss").eq(User::roleId, "sss2")
val updateRecord = User()
updateRecord.name = "newName"
userMapper!!.update(updateRecord, updateConditionWrapper)
val updateRecord = User()
updateRecord.id = 2
updateRecord.name = "haha"
userMapper.updateById(updateRecord)
// 区分:
// 链式调用 普通
UpdateChainWrapper<T> update();
// 链式调用 lambda 式。注意:不支持 Kotlin
LambdaUpdateChainWrapper<T> lambdaUpdate();
// 等价示例:
query().eq("id", value).one();
lambdaQuery().eq(Entity::getId, value).one();
// 等价示例:
update().eq("id", value).remove();
lambdaUpdate().eq(Entity::getId, value).remove();
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