使用 MyBatis 和 MySql 以编程方式创建 table
Creating a table programmatically using MyBatis and MySql
我想创建一种动态创建 table 的方法,只需将 table 名称作为变量传递即可。
我已经定义了我的 xml 映射器
<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);
}
但是当我调用我的接口时
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
如果我改为更改查询,为 table 名称添加 ``:
CREATE TABLE IF NOT EXISTS `#{tableName}`(
`ID` varchar(20) NOT NULL,
PRIMARY KEY (`ID`)
)
ENGINE=InnoDB
我明白了
### 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?
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(参见 Parameters 中的 String Substitution)。
在 DAO 中,使用注解 @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。
我想创建一种动态创建 table 的方法,只需将 table 名称作为变量传递即可。 我已经定义了我的 xml 映射器
<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);
}
但是当我调用我的接口时
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
如果我改为更改查询,为 table 名称添加 ``:
CREATE TABLE IF NOT EXISTS `#{tableName}`(
`ID` varchar(20) NOT NULL,
PRIMARY KEY (`ID`)
)
ENGINE=InnoDB
我明白了
### 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?
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(参见 Parameters 中的 String Substitution)。
在 DAO 中,使用注解 @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。