wen 02-myBatisPlus的wrapper接口的使用
![02-myBatisPlus的wrapper接口的使用
[编程语言教程]](https://www.zixueka.com/wp-content/uploads/2024/01/1706710499-aa909a8820d2061.jpg)
02-myBatisPlus的wrapper接口的使用。
1.直接先上硬菜
| 序号 | 函数名 | 说明 | 说明/例子 |
|---|---|---|---|
| 1 | eq | 等于= | eq(“name”,”二狗子”) ==> where name = ‘二狗子‘ |
| 2 | ne | 不等于 <> | ne(“name”,”二狗子”) ==> where name <> ‘二狗子‘ |
| 3 | gt | 大于 > | gt(“age”,18) ==> where age >18 |
| 4 | ge | 大于等于 >= | ge(“”age”,18) ==> where age >=18 |
| 5 | lt | 小于 < | lt(“age”,18″) ==> where age <18 |
| 6 | le | 小于等于 <= | le(“age”,18) ==> where age <=18 |
| 7 | between | between 值1 and值2 | between(“age”,18,30) ==> where age between 18 and 30 |
| 8 | notBetween | not between 值1 and值2 | not between(“age”,18,30) ==> where age not between 18 and 30 |
| 9 | like | like ‘%值%‘ | like(“name”,”二”) ==> where name like ‘%二%‘ |
| 10 | notLike | not like ‘%值%‘ | notLike(“name”,”二”) ==> where name not like ‘%二%‘ |
| 11 | likeLeft | like ‘%值‘ | likeLeft(“name”,”二”) ==> where name like ‘%二‘ |
| 12 | likeRight | like ‘值%‘ | likeRight(“name”,”二”) ==> where name like ‘二%‘ |
| 13 | isNull | 字段 is null | isNUll(”name“) ==> where name is null |
| 14 | isNotNull | 字段 is not null | isNotNull(“name”) ==> where name is not null |
| 15 | in | 字段 in ( v0,v1,v2…） | in(“age”,{1,2,3}) ==> where age in (1,2,3) |
| 16 | notIn | 字段 not in(v0,v1…） | notIn(“age”,{1,2,3}) ==> where age not in(1,2,3) |
| 17 | inSql | 字段 in ( sql语句) | inSql(“id”,”select id form user where age > 3″) ==> id in(select id form user where age > 3) |
| 18 | notInSql | 字段 not in ( sql语句) | notInSql(“id”,”select id form user where age > 3″) ==> id not in(select id form user where age > 3) |
| 19 | groupBy | 分组：group by | groupBy(“id”,”name”) ==> group by id,name |
| 20 | orderByAsc | 排序 ：order by 正序 | orderByAsc(“id”,”name”) ==> order by id ASC,name ASC |
| 21 | orderByDesc | 排序 ：order by 倒序 | orderByDesc(“id”,”name”) ==> order by id DESC,name DESC |
| 22 | orderBy | 排序：order by | orderBy(“id”,”name”) ==> order by id ASC,name ASC |
| 23 | having | having(sql语句) | having(“sum{age} > {0}”,11) ==> having sum(age) >11 |
| 24 | or | 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则用and连接)eq(“id”,1).or().eq(“name”,”二狗子”) ==> id = 1 or name = ‘二狗子‘ |
| 25 | and | and嵌套 | and(mapper.eq(“id”,1).ne(“status”,”活着“))==> id = 1 and status <> ‘活着‘ |
| 26 | apply | 拼接sql | 注意事项：该方法可用于数据库函数。动态入参的params对应前面sqlHaving{index}部分。这样是不会有sql注入风险的，反之则会有！ apply(“date_format(dateColumn,‘%Y-%m-%d‘) = {0}”,”2020-10-24″) ==> date_format(dateColumn,‘%Y-%m-%d‘) = ‘2020-10-24‘； |
| 27 | last | 无视优化规则直接拼接到sql的最后 | 注意事项：只能调用一次，多次调用以最后一次为准。有sql注入风险，需要谨慎使用。last(“limit 1”); |
| 28 | exists | 拼接 exists（sql语句） | exists(“select id from user where age = 1”) ==> exists(select id from user where age = 1); |
| 29 | notExists | 拼接 not exists（sql语句） | notExists(“select id from user where age = 1”) ==>not exists(select id from user where age = 1); |
| 30 | nested | 正常嵌套，不带and或or | nested(mapper.eq(“id”,1).ne(“status”,”活着“)) ==> (id = 1 and status <> ‘活着‘) |
