Question

我想创建一个方法来动态创建表，只是将表名作为变量传递。我已经定义了我的xml mapper

<mapper namespace="com.mappers.TableCreatorMapper">
    <cache />
    <insert id="createNewTableIfNotExists" parameterType="String" > 
        CREATE TABLE IF NOT EXISTS #{tableName} 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB
    </insert>
</mapper>

我的Java接口映射器很简单：

public interface TableCreatorMapper {
     public void createNewTableIfNotExists(String tableName);
}

但是当我打电话给我的界面时

tableCreatorMapper.createNewTableIfNotExists("test");

我得到以下异常：

org.springframework.jdbc.BadSqlGrammarException: 
### Error updating database.  Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
### The error may involve com.mappers.TableCreatorMapper.createNewTableIfNotExists-Inline
### The error occurred while setting parameters
### SQL: CREATE TABLE IF NOT EXISTS ?          (         `ID` varchar(20) NOT NULL,         PRIMARY KEY (`ID`)         )    ENGINE=InnoDB
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''test' 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
' at line 1
    at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:231)
    at org.sp

如果我改为查询，为表名添加``：

 CREATE TABLE IF NOT EXISTS `#{tableName}`(
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB

我得到了

### The error occurred while setting parameters
### SQL: CREATE TABLE IF NOT EXISTS `?`(         `ID` varchar(20) NOT NULL,         PRIMARY KEY (`ID`)         )    ENGINE=InnoDB
### Cause: java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).
; SQL []; Parameter index out of range (1 > number of parameters, which is 0).; nested exception is java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).

知道为什么吗？

Answer 1

尝试

CREATE TABLE IF NOT EXISTS ${_parameter} 
        (
        `ID` varchar(20) NOT NULL,
        PRIMARY KEY (`ID`)
        ) 
        ENGINE=InnoDB

＃{name} 用于PreparedStatement中的参数（请参阅Parameters中的字符串替换）。

Answer 2

在DAO中

，使用注释@Param void createTableIfNotExist(@Param("uuid") String uuid);

在MAPPER中

，使用$

<update id="createTableIfNotExist" parameterType="java.lang.String">
  CREATE TABLE IF NOT EXISTS `table_${uuid}` 
  (
        `id` bigint(18) NOT NULL,
        `info` varchar(18) NOT NULL,
        PRIMARY KEY (`id`)
  )
  ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='this table is generated by java code.'
</update>

<bind>也可以在MAPPER中使用。

使用MyBatis和MySql以编程方式创建表

2 个答案: