关于mybatis中llike模糊查询中#和$的使用

模糊查询：

工作中用到，写三种用法吧，第四种为大小写匹配查询

1. sql中字符串拼接

SELECT * FROM tableName WHERE name LIKE CONCAT(CONCAT(‘%’, #{text}), ‘%’);

2. 使用 ${…} 代替 #{…}

SELECT * FROM tableName WHERE name LIKE ‘%${text}%’;

3. 程序中拼接

   Java

// or String searchText = “%” + text + “%”;

String searchText = new StringBuilder(“%”).append(text).append(“%”).toString();

parameterMap.put(“text”, searchText);

SqlMap.xml

SELECT * FROM tableName WHERE name LIKE #{text};

4. 大小写匹配查询

1. SELECT *  FROM TABLENAME  WHERE UPPER(SUBSYSTEM) LIKE ‘%’ || UPPER(‘jz’) || ‘%’
2. –或者是
3. SELECT *   FROM TABLENAME  WHERE LOWER(SUBSYSTEM) LIKE ‘%’ || LOWER(‘jz’) || ‘%’

   SELECT *  FROM TABLENAME  WHERE UPPER(SUBSYSTEM) LIKE '%' || UPPER('jz') || '%'
    --或者是
   SELECT *   FROM TABLENAME  WHERE LOWER(SUBSYSTEM) LIKE '%' || LOWER('jz') || '%'

异常：

java.lang.IllegalArgumentException: modify is ambiguous in Mapped Statements collection (try using the full name including the namespace, or rename one of the entries)
 at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:466)

 at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:349)

 at org.apache.ibatis.binding.MapperMethod.setupCommandType(MapperMethod.java:137)

 at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:46)

 at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:34)

 at $Proxy10.modify(Unknown Source)

抛出这个异常的原因可能是因为mapper.xml配置文件中<mapper>的namespace属性配置错误造成的，没有根据命名空间的值（全称类名）找到相应映射接口。

如：<mapper namespace=”com.xxx.xxx.mapper.TestMapper” >